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PRINCIPAL FINANCIAL GROUP, INC. TABLE OF CONTENTS
Item 8. Financial Statements and Supplementary Data

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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM 10-K

For the transition period from                  to                 
Commission file number 1-16725

PRINCIPAL FINANCIAL GROUP, INC.
(Exact name of Registrant as specified in its charter)

(515) 247-5111
(Registrant's telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act:

        Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes ý No o

        Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Exchange Act. Yes o No ý

        Indicate by check mark whether the Registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the Registrant was required to file such reports) and (2) has been subject to such filing requirements for the past 90 days. Yes ý No o

        Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Website, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files). Yes ý No o

        Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K (§ 229.405 of this chapter) is not contained herein, and will not be contained, to the best of Registrant's knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment of this Form 10-K. o

        Indicate by check mark whether the Registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of "large accelerated filer", "accelerated filer" and "smaller reporting company" in Rule 12b-2 of the Exchange Act.

        Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act.) Yes o No ý

        As of February 6, 2013, there were outstanding 293,402,246 shares of Common Stock, $0.01 par value per share of the Registrant.

        The aggregate market value of the shares of the Registrant's common equity held by non-affiliates of the Registrant was $7,754,473,315 based on the closing price of $26.23 per share of Common Stock on the New York Stock Exchange on June 29, 2012.

Documents Incorporated by Reference

        The information required to be furnished pursuant to Part III of this Form 10-K is set forth in, and is hereby incorporated by reference herein from, the Registrant's definitive proxy statement for the annual meeting of stockholders to be held on May 22, 2013, to be filed by the Registrant with the United States Securities and Exchange Commission pursuant to Regulation 14A not later than 120 days after the year ended December 31, 2012.

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PRINCIPAL FINANCIAL GROUP, INC.
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NOTE CONCERNING FORWARD-LOOKING STATEMENTS

        This Annual Report on Form 10-K, including the Management's Discussion and Analysis of Financial Condition and Results of Operations, contains statements which constitute forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, including statements relating to trends in operations and financial results and the business and the products of the Registrant and its subsidiaries, as well as other statements including words such as "anticipate," "believe," "plan," "estimate," "expect," "intend" and other similar expressions. Forward-looking statements are made based upon management's current expectations and beliefs concerning future developments and their potential effects on us. Such forward-looking statements are not guarantees of future performance.

        Actual results may differ materially from those included in the forward-looking statements as a result of risks and uncertainties. Those risks and uncertainties include, but are not limited to the risk factors listed in Item 1A. "Risk Factors."

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PART I

Item 1.    Business

        Principal Financial Group, Inc. ("PFG") is a global investment management leader offering retirement services, insurance solutions and asset management. We offer businesses, individuals and institutional clients a wide range of financial products and services, including retirement, asset management and insurance through our diverse family of financial services companies. We have $403.0 billion in assets under management ("AUM") and approximately 18.3 million customers worldwide as of December 31, 2012.

        We primarily focus on small and medium-sized businesses, which we define as companies with less than 1,000 employees, providing a broad array of retirement and employee benefit solutions to meet the needs of the business, the business owner and their employees. We are the leading provider of corporate defined contribution plans in the U.S., according to Spectrem Group. We are also the leading employee stock ownership plan consultant. In addition, we are a leading provider of nonqualified plans, defined benefit plans and plan termination annuities. We are also one of the largest providers of specialty benefits insurance product solutions.

        We believe small and medium-sized businesses are an underserved market, offering attractive growth opportunities in the U.S. in retirement services and other employee benefits. We also believe there is a significant opportunity to leverage our U.S. retirement expertise into select international markets that have adopted or are moving toward private sector defined contribution pension systems. This opportunity is particularly compelling as aging populations around the world are driving increased demand for retirement accumulation, retirement asset management and retirement income management solutions.

Our Reportable Segments

        We organize our businesses into the following reportable segments:

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Retirement and Investor Services;



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Principal Global Investors;



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Principal International and



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U.S. Insurance Solutions.

        We also have a Corporate segment, which consists of the assets and activities that have not been allocated to any other segment.

        See Item 8. "Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 16, Segment Information" for financial results of our segments, including our operating revenues for our products and services described in each of the subsequent segment discussions.

Retirement and Investor Services Segment

        Our asset accumulation activities in the U.S. date back to the 1940s when we first began providing pension plan products and services. We now offer a comprehensive portfolio of asset accumulation products and services for retirement savings and investment:

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To businesses of all sizes with a concentration on small and medium-sized businesses, we offer products and services for defined contribution pension plans, including 401(k) and 403(b) plans, defined benefit pension plans, nonqualified executive benefit plans and employee stock ownership plan ("ESOP") consulting services. For more basic investment needs, we offer SIMPLE Individual Retirement Accounts ("IRA") and payroll deduction plans;



•

To large institutional clients, we also offer investment-only products, including guaranteed investment contracts ("GICs") and funding agreements and



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To employees of businesses and other individuals, we offer the ability to accumulate savings for retirement and other purposes through mutual funds, individual annuities and bank products.

        We organize our Retirement and Investor Services operations into two business groupings:

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Accumulation business — which includes full service accumulation, Principal Funds (our mutual fund business), individual annuities and bank and trust services; and



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Guaranteed business — which includes investment only and full service payout.

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Accumulation Business

Full Service Accumulation

Products

        We offer a wide variety of investment and administrative products for defined contribution pension plans, including 401(k) and 403(b) plans, defined benefit pension plans, nonqualified executive benefit plans and ESOPs. A 403(b) plan is a plan described in Section 403(b) of the Internal Revenue Code that provides retirement benefits for employees of tax-exempt organizations and public schools.

        Full service accumulation products respond to the needs of plan sponsors seeking both administrative and investment services for defined contribution plans or defined benefit plans. The investment component of both the defined contribution and defined benefit plans may be in the form of a general account, separate account, a mutual fund offering or a collective investment trust. In addition, defined contribution plans may also offer their own employer security as an investment option.

        We deliver both administrative and investment services to our defined contribution plan and defined benefit plan customers through annuities and mutual funds. Group annuities and the underlying investment options are not required to be registered with the United States Securities and Exchange Commission ("SEC"). Our mutual fund offering is called Principal Advantage. It is a qualified plan product based on our series mutual fund, Principal Funds, Inc. We offer investments covering the full range of stable value, equity, fixed income, real estate and international investment options managed by our Principal Global Investors segment as well as third-party asset managers.

        As of December 31, 2012, we provided full service accumulation products to (a) over 30,700 defined contribution pension plans, of which approximately 25,500 were 401(k) plans, including $93.7 billion in assets and covering 3.4 million eligible plan participants, and (b) to over 2,400 defined benefit pension plans, including $15.9 billion in assets and covering over 354,000 eligible plan participants. As of December 31, 2012, approximately 61% of our full service accumulation account values were managed by our affiliated asset manager, Principal Global Investors. Third-party asset managers provide asset management services with respect to the remaining assets.

Markets and Distribution

        We offer our full service accumulation products and services to employer-sponsored pension plans, including qualified and nonqualified defined contribution plans and defined benefit plans. Our primary target market is plans sponsored by small and medium-sized businesses, which we believe remains under-penetrated. According to Spectrem Group, in 2011, only 25% of businesses with between 10 and 49 employees, 50% of businesses with between 50 and 99 employees, 56% of businesses with between 100 and 249 employees and 69% of businesses with between 250 and 500 employees offered a 401(k) plan. The same study indicates that 75% of employers with between 500 and 1,000 employees, 78% of employers with between 1,000 and 5,000 employees and 79% of employers with 5,000 or more employees offered a 401(k) plan in 2011.

        We distribute our full service accumulation products and services nationally, primarily through a captive retirement services sales force. As of December 31, 2012, over 117 retirement services sales representatives in over 42 offices, operating as a wholesale distribution network, maintained relationships with over 12,100 independent brokers, consultants and agents. Retirement services sales representatives are an integral part of the sales process alongside the referring consultant or independent broker. We compensate retirement services sales representatives through a blend of salary and production-based incentives, while we pay independent brokers, consultants and agents a commission or fee.

        As of December 31, 2012, we had a separate staff of over 280 service and education specialists located in the sales offices who play a key role in the ongoing servicing of pension plans by providing local services to our customers, such as reviewing plan performance, investment options and plan design; communicating the customers' needs and feedback to us and helping employees understand the benefits of their pension plans. The following summarizes our distribution channels:

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We distribute our annuity-based products through sales representatives, agents and brokers who are primarily state licensed individuals.



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Principal Advantage, our mutual fund-based product, is targeted at defined contribution plans through broker-dealer distribution channels. Principal Advantage gives us access to Financial Industry Regulatory Authority-registered distributors who are not traditional sellers of annuity-based products and broadens opportunities for us in the investment advisor and broker-dealer distribution channels.



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Principal Retirement Income Edge® is designed to create a coordinated experience from accumulation to income management for advisors to use with their individual clients and plan participants who are nearing or enjoying retirement. The Principal Retirement Income Edge® program provides education and planning tools as well as a wide variety of products such as annuities, mutual funds and bank products to provide personalized income management solutions.



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Through our Retire Secure strategy we provide financial education and assistance to individual investors who are participants/members of employer-based accumulation solutions to help them achieve financial security.

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        We believe our approach to full service accumulation plan services distribution gives us a local sales and service presence that differentiates us from many of our competitors. We have also established a number of marketing and distribution relationships to increase the sales of our accumulation products.

Principal Funds

        We have been providing mutual funds to customers since 1969. We offer mutual funds to individuals, businesses and institutional investors for use within variable life and variable annuity contracts, for use in employer-sponsored pension plans, as a rollover investment option, and for general investment purposes.

Products and Services

        Principal Funds plans to grow into a top advisor sold mutual fund company with a sales force focused on multiple channels. As of November 2012, as reported by the Strategic Insight, we are ranked 20^th according to AUM (long term funds) of the top 50 intermediary sold mutual funds. We provide accounting, compliance, corporate governance and product development for all mutual funds we organize.

        Principal Funds, Inc.    Principal Funds, Inc. ("PFI") is a series mutual fund that, as of December 31, 2012, offered 64 investment options. This fund's five R class shares act as the funding vehicle for Principal Advantage, the defined contribution product described above under "Retirement and Investor Services Segment-Full Service Accumulation-Products." This fund also offers three classes of shares to individuals. One of these three share classes is for IRA rollovers (J shares) and two are for general investment purposes (A and C shares). Two additional classes of shares are available: (1) I shares, which are offered primarily to specified institutional investors, and (2) P shares, which are used primarily in adviser fee-based programs. As of December 31, 2012, the fund held $81.5 billion of AUM. We report the results for this fund in "Full Service Accumulation" or "Principal Funds" based on the distribution channel associated with the AUM.

        Principal Variable Contracts Funds, Inc.    Principal Variable Contracts Funds, Inc. is a series mutual fund that, as of December 31, 2012, provided 36 investment options for variable annuity and variable life insurance contracts issued by Principal Life Insurance Company ("Principal Life") and other insurance companies not affiliated with Principal Life. As of December 31, 2012, this fund had AUM of $6.5 billion. AUM backing Principal Life variable annuity contracts is reported in this segment under "Individual Annuities." AUM backing Principal Life variable life insurance contracts is reported in the U.S. Insurance Solutions segment.

        Principal Managed Portfolio.    Principal Managed Portfolio is an advisory product offered by our registered investment advisor, Princor Financial Services Corporation ("Princor"), which permits the client to invest only in Principal Funds, Inc. Clients are charged a quarterly asset-based fee on this product. As of December 31, 2012, Principal Managed Portfolio had accumulated $668.2 million in assets.

        Principal Advisory Select and Principal Dynamic Portfolios.    These are advisory products offered by our registered investment advisor, Princor, which permits the client to invest in a broad array of investments. Clients are charged a quarterly asset-based fee on these products. As of December 31, 2012, these products had accumulated $2.0 billion in assets.

Markets and Distribution

        Our markets for PFI's retail share classes are individuals seeking to accumulate savings for retirement and other purposes, as well as nonqualified individual savings plans utilizing payroll deductions. We also market PFI's retail share classes to participants in pension plans who are departing their plans and reinvesting their retirement assets into individual retirement accounts.

        We sell PFI's share classes primarily through registered representatives from other broker-dealers; affiliated financial representatives; independent brokers registered with our securities broker-dealer, Princor; direct deposits from our employees and others and Principal Connection. As of December 31, 2012, 63 retail sales representatives across the United States, operating as a wholesale distribution network, maintained relationships with over 47,000 independent brokers, consultants and agents. Principal Connection is our direct response distribution channel for retail financial services products to individuals. Principal Connection's services are available over the phone, on the Internet or by mail. Princor recruits, trains and supervises registered representatives selling our products through Principal Connection.

Individual Annuities

        Individual annuities offer a tax-deferred means of accumulating retirement savings, as well as a tax-efficient source of income during the payout period.

Products

        We offer both fixed and variable annuities to individuals and pension plans. Individual annuities may be categorized in two ways: (1) deferred, in which case assets accumulate until the contract is surrendered, the customer dies or the

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customer begins receiving benefits under an annuity payout option, or (2) immediate/payout, in which case payments begin within one year of issue and continue for a fixed period of time or for life.

        Fixed Deferred Annuities.    Our individual fixed deferred annuities consist of both single premium deferred annuity contracts and flexible premium deferred annuity contracts ("FPDAs"). Some FPDA contracts limit the period of time deposits are allowed (e.g., only one year). For most contracts, the principal amount is guaranteed. We credit the customer's account with a fixed interest rate and for a specified number of years. Thereafter, we reset, typically annually, the interest rate credited to the contract based upon our discretion, subject to contractual minimums, by taking into account market and other conditions. We also offer a fixed deferred annuity where the interest credited is linked to an external equity index, subject to maximum and minimum values. Our major source of income from fixed deferred annuities is the spread between the investment income earned on the underlying general account assets and the interest rate credited to the contracts. We bear the investment risk because, while we credit customers' accounts with a stated interest rate, we cannot be certain the investment income we earn on our general account assets will exceed that rate. The Principal Global Investors segment manages the assets supporting these contracts.

        Variable Deferred Annuities.    Individual variable deferred annuities are savings vehicles through which the customer makes one or more deposits of varying amounts and intervals. Customers have the flexibility to allocate their deposits to investment sub-accounts managed by the Principal Global Investors segment or other third-party asset managers. As of December 31, 2012, 84% of our $6.6 billion in variable annuity account balances was allocated to investment sub-accounts and our general account, which are managed by the Principal Global Investors segment and 16% was allocated to investment sub-accounts managed by third-party asset managers. Generally speaking, the customers bear the investment risk and have the right to allocate their assets among various separate investment sub-accounts. The value of the annuity fluctuates in accordance with the experience of the investment sub-accounts chosen by the customer. Customers have the option to allocate all or a portion of their account to our general account, in which case we credit interest at rates we determine, subject to contractual minimums. Customers may elect a living benefit guarantee (commonly known in the industry as a guaranteed minimum withdrawal benefit, or "GMWB"). We bear the GMWB investment risk. We attempt to hedge the GMWB investment risk through the use of sophisticated risk management techniques. As of December 31, 2012, $3.6 billion of the $6.6 billion of variable annuity account value had the GMWB rider. Our major source of revenue from variable annuities is mortality and expense fees we charge to the customer, generally determined as a percentage of the market value of the assets held in a separate investment sub-account.

        Fixed Immediate Annuities.    Our individual fixed immediate annuities consist almost exclusively of single premium immediate annuity contracts ("SPIAs"). SPIAs are products where the customer makes a single deposit and from which periodic benefit payments are made. Payments may be contingent upon the survival of one or two individuals or payments may be fixed, meaning payments are contractually guaranteed and do not depend on the continuing survival of any individual. Our major source of income from fixed immediate annuities is the spread between the investment income earned on the underlying general account assets and the interest rate implied in the calculation of annuity benefit payments. We bear the investment risk because we cannot be certain the investment income we earn on our general account assets will exceed the rate implied in the SPIA contracts. The Principal Global Investors segment manages the assets supporting these contracts.

Markets and Distribution

        Our target markets for individual annuities include owners, executives and employees of small and medium-sized businesses and individuals seeking to accumulate and/or eventually receive distributions of assets for retirement. We market both fixed and variable annuities to individuals for both qualified and nonqualified retirement savings.

        We sell our individual annuity products through our affiliated financial representatives, who accounted for 46%, 50% and 43% of annuity sales for the years ended December 31, 2012, 2011 and 2010, respectively. The remaining sales were made through banks, brokerage general agencies, mutual fund companies, Principal Connection and unaffiliated broker-dealer firms. Affiliated financial representatives continued to be the primary distribution channel of our variable deferred annuities. The majority of overall annuity sales, however, were from non-affiliated distribution channels, as a result of focused efforts to increase fixed annuity sales through non-affiliated distribution channels.

Bank and Trust Services

        Bank and trust services includes Principal Bank and Principal Trust Company. Principal Bank is a federal savings bank that began its activities in February 1998. As of December 31, 2012, Principal Bank had over 254,000 customers and approximately $2.4 billion in assets. Delaware Charter Guarantee & Trust Company, dba Principal Trust Company, is a Delaware state chartered non-deposit trust company that was chartered in 1899. It is one of the largest non-deposit trust companies in the U.S. As of December 31, 2012, we served as trustee to over 247,000 accounts, which held assets of approximately $127.6 billion. Principal Trust Company may not accept deposits and cannot make personal or commercial loans.

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Products

        Our current bank products and services include a suite of consumer checking and savings accounts, money market accounts, certificates of deposit ("CDs"), individual retirement accounts, small account rollovers from qualified retirement plans and sweep accounts associated with affiliated brokerage accounts. Principal Bank participates in the Certificate of Deposit Account Registry Service program through which certain customer CDs are exchanged for CDs of similar amounts from participating banks. The deposit products provide a relatively stable source of funding and liquidity and are used to fund purchases of investment securities and loans.

        Principal Trust Company specializes in providing trust solutions for a full array of employee benefit plans and accounts including 401(k) and 403(b) plans, defined benefit pension plans, nonqualified executive benefit plans, ESOPs, and self-directed tax-advantaged savings accounts, such as IRAs. Principal Trust Company also maintains collective investment funds and provides personal trust services.

Markets and Distribution

        We offer our bank products and services to employees of businesses and other individuals with a primary focus on helping customers accumulate savings for retirement and other purposes. We also pursue asset retention strategies with customers who seek to transfer assets from our other asset accumulation products by offering them our banking products and services. Principal Bank services customers through the telephone, mail and Internet.

        We deliver our directed trust services and collective investment funds to customers through our PFG affiliates and affiliated financial representatives. Administrative trust services for self-directed tax-advantaged savings accounts are sold through non-affiliated brokerage firms, clearing firms, financial advisors and asset managers.

Guaranteed Business

Investment Only

Products

        The three primary products for which we provide investment only services are: GICs, funding agreements and other investment only products.

        GICs and funding agreements pay a specified rate of return. The rate of return can be a floating rate based on an external market index or a fixed rate. Our investment only products contain provisions disallowing or limiting early surrenders, including penalties for early surrenders and minimum notice requirements.

        Deposits to investment only products are predominantly in the form of single payments. As a result, the level of new deposits can fluctuate from one fiscal quarter to another. Assets invested in GICs and funding agreements generate a spread between the investment income earned by us and the amount credited to the customer. Our other investment only products consist of separate accounts invested in either equities or fixed income instruments. The Principal Global Investors segment manages the assets supporting investment only account values.

Markets and Distribution

        We market GICs and funding agreements primarily to pension plan sponsors and other institutions. We also offer them as part of our full service accumulation products. We sell our GICs primarily to plan sponsors for funding of tax-qualified retirement plans. We sell our funding agreements directly to institutions that may or may not be pension funds and unconsolidated special purpose vehicles domiciled either in the U.S. or offshore for funding agreement-backed note programs. The funding agreements sold as part of these funding agreement-backed note programs work by having investors purchase debt obligations from the special purpose vehicle which, in turn, purchases the funding agreement from us with terms similar to those of the debt obligations. The strength of this market is dependent on debt capital market conditions. As a result, our sales through this channel can vary widely from one quarter to another. In addition to the special purpose vehicle selling the funding agreement-backed notes to U.S. and foreign institutional investors, the special purpose vehicle may also sell notes to U.S. retail investors through a SEC-registered shelf debt issuance program.

Full Service Payout

Products

        Full service payout products respond to the needs of pension plan participants who, upon retirement or termination of their employment, seek a guaranteed income stream. Plan participants who seek these services include those from pension plans we service, as well as pension plans other providers service. We primarily offer single premium group annuities, which are immediate or deferred annuities that provide a current or future specific income amount, fully guaranteed by us. These are available to defined contribution and defined benefit plan participants. We make regular payments to individuals, invest the underlying assets on their behalf and provide tax reporting to them. We also reinsure single premium immediate annuities issued by another insurer.

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        Single premium group annuities are traditionally used in conjunction with defined benefit plans, particularly those where the plan is being terminated. In such instances, the plan sponsor transfers all its obligations under the plan to an insurer by paying a single premium. Increasingly, these products are purchased by defined contribution plan participants who reach retirement age. Generally, plan sponsors restrict their purchases to insurance companies with superior or excellent financial quality ratings because the Department of Labor has mandated that annuities be purchased only from the "safest available" insurers.

        Premium received from full service payout products are generally in the form of single payments. As a result, the level of new premiums can fluctuate depending on the number of retirements and large-scale annuity sales in a particular fiscal quarter. The Principal Global Investors segment manages the assets supporting full service payout account values.

Markets and Distribution

        Our primary distribution channel for full service payout products is comprised of several specialized home office sales consultants working through consultants and brokers that specialize in this type of business. Our sales consultants also make sales directly to institutions. Our nationally dispersed retirement services sales representatives act as a secondary distribution channel for these products. Principal Connection also distributes full service payout products to participants in plans we service who are terminating employment or retiring.

Principal Global Investors Segment

        Our Principal Global Investors segment manages assets for sophisticated investors around the world, using a multi-boutique strategy that enables the segment to provide an expanded range of diverse investment capabilities including equity, fixed income and real estate investments. We also have experience in currency management, asset allocation, stable value management and other structured investment strategies. We focus on providing services to our other segments and third-party institutional clients. We maintain offices in Australia, Brazil, Dubai, Germany, Hong Kong, Japan, Netherlands, Singapore, the United Kingdom and the United States.

        We deliver our products and services through our network of specialized investment groups and boutiques including Principal Global Investors — Equities; Principal Global Investors — Fixed Income; Principal Real Estate Investors, LLC; Principal Enterprise Capital, LLC; Spectrum Asset Management Inc.; Post Advisory Group, LLC; Columbus Circle Investors; Edge Asset Management Inc.; Morley Financial Services Inc.; Macro Currency Group; Finisterre Capital LLP; Origin Asset Management LLP and Multi-Asset Advisors Group. As of December 31, 2012, Principal Global Investors and its boutiques managed $263.2 billion in assets.

Products and Services

        Our products and services are provided for a fee as defined by client mandates. Our fees are generally driven by AUM. We are diversified across three primary asset classes.

        Equity Investments.    As of December 31, 2012, Principal Global Investors — Equities along with Columbus Circle Investors, Edge Asset Management Inc. and Origin Asset Management LLP managed $79.1 billion in global equity assets. Our equity capabilities encompass large-cap, mid-cap and small-cap stocks in developed and emerging markets worldwide. As of December 31, 2012, 44% of equity AUM was derived from our pension products, 26% from other products of PFG and the remaining 30% from third-party institutional clients.

        Fixed Income Investments.    As of December 31, 2012, Principal Global Investors — Fixed Income along with Spectrum Asset Management Inc.; Post Advisory Group, LLC; Edge Asset Management Inc.; Morley Financial Services Inc. and Finisterre Capital LLP managed $130.1 billion in global fixed income assets. Collectively, our experience in fixed income management spans multiple economic and credit market cycles, and encompasses all major fixed income sectors and security types. Our research and risk management capabilities in worldwide debt markets provide a strong foundation for broadly diversified "multi-sector" portfolios, tailored to specific client objectives. As of December 31, 2012, 32% of these assets were derived from our pension products, 33% from other products of PFG, and the remaining 35% from third-party institutional clients.

        Real Estate Investments.    Principal Global Investors, through its affiliates Principal Real Estate Investors, LLC and Principal Enterprise Capital, LLC, managed a portfolio of primarily U.S. commercial real estate assets of $44.8 billion as of December 31, 2012. Principal Real Estate Investors, LLC provides our clients with a broad range of real estate investment options including private real estate equity, commercial mortgages, bridge/mezzanine loans, commercial mortgage-backed securities and real estate investment trust securities. As of December 31, 2012, 26% of the commercial real estate portfolio was derived from our pension products, 28% from other products of PFG and the remaining 46% from third-party institutional clients.

        Other.    We offer products and services through other asset classes including managing currency mandates through our Macro Currency Group boutique. As of December 31, 2012, we managed $9.2 billion with 100% of these assets derived from third-party institutional clients.

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        Multi-Asset Advisors Group was established to provide advice on multi-asset strategies to global clients and to develop and manage customized multi-asset products to address specific client needs. Multi-Asset Advisors Group helps Principal Global Investors optimize our broad range of capabilities while enhancing our position as a thought leader and trusted advisor to large institutional clients.

Markets and Distribution

        We employed 121 institutional sales, relationship management and client service professionals as of December 31, 2012, who worked with consultants and directly with large investors to acquire and retain third-party institutional clients. As of December 31, 2012, Principal Global Investors and its boutiques had approximately 665 third-party institutional clients with $98.2 billion of AUM in 36 countries.

Principal International Segment

        Our Principal International segment has operations in Brazil, Chile, China, Hong Kong Special Administrative Region ("SAR"), India, Mexico and Southeast Asia. We focus on countries with large middle classes, favorable demographics, and growing long-term savings, ideally with defined contribution retirement markets. We entered these locations through acquisitions, start-up operations and joint ventures.

        The activities of our Principal International segment reflect our efforts to accelerate the growth of our AUM by capitalizing on the international trend toward private sector defined contribution pension systems and individual long-term savings. Through the Principal International segment, we offer retirement products and services, annuities, mutual funds, institutional asset management and life insurance accumulation products.

Products, Markets and Distribution

        Brazil.    We offer pension, retirement income and asset accumulation products through a co-managed joint venture, Brasilprev Seguros e Previdencia ("Brasilprev") in which PFG owns 25% of the economic interest and 50.01% of the voting shares. The partner is Banco do Brasil ("Banco"), which had approximately 5,340 Brazilian branches as of September 30, 2012. Brasilprev has an exclusive agreement with Banco to distribute pension, retirement and long-term asset accumulation products. Our joint venture provides defined contribution products, complementary life protection and payout solutions for the retirement needs of employers and individuals. Banco's employees sell these products directly to individual clients through its bank branches. In addition, our joint venture reaches corporate clients through two wholesale distribution channels: (1) a network of independent brokers who sell to the public and (2) Banco's corporate account executives who sell to existing and prospective corporate clients. According to Federação Nacional de Previdência e Vida, our joint venture ranked third in the Brazilian private pension market based upon managed assets as of October 31, 2012.

        On April 2, 2012, we purchased a 60% indirect ownership in Claritas Administração de Recursos Ltda ("Claritas"), a leading Brazilian mutual fund and asset management company. The Sao Paulo-based company manages equity funds, balanced funds, managed accounts and other strategies for affluent clients and institutions through its multi-channel distribution network. This purchase positions us to capture future growth expected in the mutual fund and asset management business in Brazil.

        Chile.    We offer long-term savings products, retirement annuities, mutual funds, life insurance accumulation products and institutional asset management services.

        Retirement annuities are offered to individuals exiting the pre-retirement accumulation system. Annuity products are distributed through a network of brokers and independent agents numbering approximately 440 as of December 31, 2012.

        We serve the individual and group voluntary/complementary long-term savings market by offering "APV plans" (qualified individual retirement solutions) and "APVC plans" (qualified group retirement solutions that are similar to the U.S. 401(k) product line). According to the Asociacion de Adminstradoras de Fondos Mutuous de Chile, we ranked first in AUM for mutual fund companies offering these plans in Chile as of November 30, 2012. The plans, together with non-qualified mutual fund products, are distributed to retail clients through our proprietary sales force, financial advisors, brokerage houses, alliances with financial institutions and one of the largest retailers in Chile, Falabella.

        Life insurance accumulation products are also offered to individuals through brokers and financial advisors. We also offer institutional asset management services to pension funds, insurance companies, mutual fund companies and investment platforms through our proprietary sales force.

        On October 8, 2012, we signed a definitive agreement to acquire AFP Cuprum S.A. ("Cuprum"). The agreement required Empresas Penta S.A. and Inversiones Banpenta Limitada to sell their 63% ownership in Cuprum pursuant to a public tender offer that also included the remaining 37% of publicly traded shares. The transaction closed on February 4, 2013, resulting in an approximately 90% ownership stake in Cuprum. Cuprum is a leading pension manager in Chile, whose products include mandatory employee-funded pension plans, voluntary pension products (APV) and other long-term savings products.

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        China.    We offer mutual funds and asset management services to individuals and institutions through a minority-held joint venture that includes China Construction Bank ("CCB"), the majority partner. We sell mutual funds primarily through our partner bank, CCB. The bank provides extensive distribution capabilities for the joint venture in terms of brand awareness and the number of branch outlets, which number approximately 13,600.

        Hong Kong SAR.    We offer defined contribution pension and mutual fund products to both corporate and retail clients and also provide institutional asset management services.

        We actively compete in the defined contribution pension plan market. The government currently requires both employers and employees to each contribute 5% of an employee's income to a Mandatory Provident Fund ("MPF"). We target small and medium-sized employers and distribute products mainly through strategic alliances with intermediaries, e.g., insurance companies, brokers, consultants and banks. We have expanded our distribution capability to complement our MPF and mutual fund businesses by developing a proprietary sales force through a wholly owned investment financial planning company that will focus on retirement and long-term investment products.

        We sell mutual funds to retail customers primarily through strategic alliances with banks. To grow institutional asset management, our operations in Hong Kong SAR leverage Principal Global Investors' regional asset management and sales resources to jointly secure mandates.

        India.    We offer mutual funds and asset management services to both retail and corporate customers.

        In the mutual funds market, we compete by managing and administering funds for both individuals and corporations through a majority-owned joint venture. The minority partners are Punjab National Bank and Vijaya Bank, two large Indian commercial banks with a combined network of approximately 7,000 branches. Mutual funds are sold through regional offices and other bank branches located throughout India. In addition to the current mutual fund business, we are positioning ourselves to compete in the emerging pension and long-term savings market in India through the launch of a proprietary distribution company in October 2012 that will focus on retirement and long-term investment products.

        Mexico.    We offer defined contribution pension products, mutual funds, annuities and asset management services to institutional clients.

        Through our AFORE pension company, we manage and administer approximately 3.9 million individual retirement accounts under the mandatory privatized social security system for all non-government employees in Mexico. We distribute products and services through a proprietary sales force of approximately 1,200 sales representatives as of December 31, 2012, as well as independent brokers who sell directly to individuals. In addition, we have a distribution arrangement for the distribution of Principal AFORE's products through HSBC Bank's extensive network in Mexico.

        Our mutual fund company distributes products and services through a sales force of approximately 70 employees and through distribution agreements with other financial entities. We administer previously sold annuities and life products.

        Mexico has institutional asset management services, offering both domestic and international products.

        Southeast Asia.    We offer conventional and Islamic mutual funds and fund management services through our minority-held joint venture with CIMB Group, the majority partner. CIMB Group is the second largest Malaysian bank with a strong presence in many Asian countries. The joint venture has a sales force of approximately 6,200 mutual fund agents selling to retail customers as of December 31, 2012. We also market mutual funds through wholesale bank channels. The joint venture's main bank channels include approximately 1,100 bank branches throughout Malaysia, Indonesia, Thailand and Singapore. The joint venture also distributes its mutual funds through third party institutions including other banks and security houses.

        CIMB-Principal Asset Management ranked second in total unit trust assets managed and second in Islamic unit trust assets managed in the Malaysian asset management industry as of November 30, 2012. The joint venture also manages a significant amount of institutional asset mandates.

        In November 2012, we began operations for a voluntary retirement accumulation business under the Private Retirement Scheme ("PRS") through our joint venture in Malaysia, CIMB-Principal Asset Management. Contributions through the PRS scheme allows for both individual and employer tax advantaged contributions.

        The joint venture also has operations in Singapore (CIMB-Principal Asset Management (S) Pte Ltd), Indonesia (PT CIMB-Principal Asset Management) and Thailand (CIMB-Principal Asset Management Company Limited).

U.S. Insurance Solutions Segment

        Our U.S. Insurance Solutions segment offers individual and group insurance solutions. We focus on providing comprehensive insurance solutions for small and medium-sized businesses and their owners and executives. We organize our operations into two divisions: Individual Life Insurance and Specialty Benefits Insurance. However, we share key resources in our core areas such as strategic leadership, distribution, and marketing.

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Individual Life Insurance

        We began as an individual life insurer in 1879. Our U.S. operations administer approximately 539,000 individual life insurance policies with over $167.4 billion of individual life insurance in force as of December 31, 2012. We assist not only in personal insurance but also specialize in business insurance needs for small to medium-sized companies through our wide range of business and nonqualified solutions.

        Small and medium-sized companies are challenged with how to build quality benefits packages for executives, how to transition the company's ownership to a partner or family member and how to save for retirement. In addition, executives and other key employees often have personal insurance needs. These needs are the focus of our products within the individual life insurance arena.

Products and Services

        Our Business Owner and Executive Solutions platform as well as our nonqualified deferred compensation offering combines administration and consulting to service our client's needs. We target the business and personal insurance needs of owners and executives of small and medium-sized businesses with an increasing focus on providing insurance solutions for nonqualified executive benefits. In addition, we market our products to meet traditional retail insurance needs. We offer a variety of individual life insurance products, including universal life insurance, variable universal life insurance and term life insurance.

        Universal and Variable Universal Life Insurance.    Universal and variable universal life insurance products offer the policyholder the option of adjusting both the premium and the death benefit amounts of the insurance contract. Universal life insurance typically includes a cash value account that accumulates at a credited interest rate based on the investment returns of the block of business. Variable universal life insurance is credited with the investment returns of the various investment options selected. For the year ended December 31, 2012, 77% of individual life insurance annualized first year premium sales were generated from universal and variable universal life insurance products. Universal and variable universal life insurance represents 69% of individual life insurance premium and deposits for the year ended December 31, 2012, and 45% of individual life insurance in force as of December 31, 2012. Variable universal life insurance products represented 27% of our universal and variable universal life insurance deposits for the year ended December 31, 2012.

        After a deduction for policy level expenses, we credit net deposits to an account maintained for the policyholder. For universal life contracts, the entire account balance is invested in the general account. Interest is credited to the policyholder's account based on the earnings on general account investments. For variable universal life contracts, the policyholder may allocate the account balance among our general account and a variety of separate account choices. Interest is credited on amounts allocated to the Principal Life general account in the same manner as for universal life. Net investment performance on separate account investments is allocated directly to the policyholder accounts; the policyholder bears the investment risk. Some of our universal life and variable universal life insurance contracts contain what are commonly referred to as "secondary" or "no-lapse" guarantee provisions. A no-lapse guarantee keeps the contract in force, even if the contractholder's account balance is insufficient to cover all of the contract charges, provided that the contractholder has continually paid a specified minimum premium.

        Traditional Life Insurance.    Traditional life insurance includes participating whole life, adjustable life products and non-participating term life insurance products. Participating products and non-participating term life insurance products represented 3% and 20%, respectively, of our individual life insurance annualized first year premium sales for the year ended December 31, 2012, and 13% and 42%, respectively, of individual life insurance in force as of December 31, 2012. Adjustable life insurance products provide a guaranteed benefit in return for the payment of a fixed premium and allow the policyholder to set the coverage period, premium and face amount combination. Term insurance products provide a guaranteed death benefit for a specified period of time in return for the payment of a fixed premium. Policyholder dividends are not paid on term insurance.

Specialty Benefits Insurance

        Specialty benefits insurance, which includes group dental, vision, life and disability insurance, wellness programs and individual disability insurance, is an important component of the employee benefit offering at small and medium-sized businesses. We offer traditional employer sponsored and voluntary products for group dental, vision, life and disability. We also offer group dental, vision, and disability on a fee-for-service basis.

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Products and Services

        Group Dental and Vision Insurance.    We began selling group dental and vision insurance in the late 1960's. Our plans provide partial reimbursement for dental and vision expenses. As of December 31, 2012, we had nearly 34,000 group dental and vision insurance policies in force covering over 893,000 employee lives. According to Life Insurance and Market Research Association ("LIMRA"), we were the 7th largest group dental insurer in terms of number of contracts/employer groups in force in 2011. In addition to indemnity and preferred provider organization dental offered on both an employer paid and voluntary basis, we offer a prepaid dental plan in Arizona through our Employers Dental Services, Inc. subsidiary. On November 1, 2012, we finalized the purchase of a 100% interest in First Dental Health, a California based independent dental preferred provider organization. We acquired First Dental Health to expand our owned dental networks primarily in California.

        Group Life Insurance.    Group life insurance was one of our first group products beginning in the early 1940's. Our group life insurance provides coverage to employees and their dependents for a specified period. As of December 31, 2012, we had over 45,000 group policies providing over $115.3 billion of group life insurance in force to approximately 1.9 million employee lives. According to LIMRA in 2011, we were ranked 6th in the U.S. in terms of the number of group life insurance contracts in force. We currently sell traditional group life insurance that does not provide for accumulation of cash values on both an employer paid and voluntary basis. Our group life insurance business remains focused on the traditional, annually renewable term product. Group term life and group universal life accounted for 97% and 3%, respectively, of our total group life insurance in force as of December 31, 2012. We no longer market group universal life insurance to new employer groups.

        Group Disability Insurance.    Group disability insurance has also been sold since the early 1940's. Our group disability insurance provides a benefit to insured employees who become disabled. In most instances, this benefit is in the form of a monthly income. Our group disability products include both short-term and long-term disability, offered on both an employer paid and voluntary basis. As of December 31, 2012, long-term disability represents 65% of total group disability premium, while short-term disability represents 35% of total group disability premium. In addition, we provide disability management services, also called rehabilitation services, to assist individuals in returning to work as quickly as possible following disability. We also work with disability claimants to improve the approval rate of Social Security benefits, thereby reducing payment of benefits by the amount of Social Security payments received. As of December 31, 2012, we served approximately 1.3 million employee lives under nearly 33,000 contracts. According to LIMRA, our group short-term disability business was ranked 5th and our group long-term disability business was ranked 4th in the U.S. as of December 31, 2011, in terms of number of contracts/employer groups in force.

        Individual Disability Insurance.    Individual disability insurance has been sold since the early 1950's. Our individual disability insurance products provide income protection to the insured member and/or business in the event of disability. In most instances, this benefit is in the form of a monthly income. In addition to income replacement, we offer products to pay business-related costs such as overhead expenses for a disabled business owner, buy-out costs for business owners purchasing a disabled owner's interest in the business, expenditures for replacement of a key person and business loan payments. We also offer a product to protect retirement savings in the event of disability. As of December 31, 2012, we served approximately 150,000 individual disability policyholders, with our individual disability business being ranked 7th in the U.S. as of December 31, 2011, in terms of premium in force, according to LIMRA.

        Wellness.    We recognize the importance of promoting healthy behavior. Our programs are designed to improve health, reduce health insurance claim costs, reduce absenteeism and increase employee productivity. We work with employers to create a healthy culture through our year round wellness program, wellness screenings, counseling to high risk participants and other services. Wellness has been a part of the Specialty Benefits Insurance division since 2011.

        Fee-for-Service.    We offer administration of group dental, disability and vision benefits on a fee-for-service basis. The fee-for-service business also became a part of the Specialty Benefits Insurance division in 2011.

U.S. Insurance Solutions Markets and Distribution

        For each of our products, administration and distribution channels are customized to meet customer needs and expectations for that product.

        We sell our individual life and individual disability income products in all 50 states and the District of Columbia, primarily targeting owners and executives of small and medium-sized businesses. Small and medium-sized business sales represented 55% of individual life sales and 60% of individual disability sales for the year ended December 31, 2012. Much of our life insurance sales efforts focus on the Business Owner & Executive Solutions market. This strategy offers solutions to address business owner financial challenges such as exiting the business, business transition, retaining key employees and retirement planning. Key employees also have needs to supplement retirement income, survivor income, and business protection. We believe the Business Owner & Executive Solutions segment offers growth opportunities and we will continue to develop strategies to capitalize on this expanding market.

        We distribute our individual life and individual disability insurance products through our affiliated financial representatives and independent brokers, as well as other marketing and distribution alliances. Affiliated financial representatives were responsible for 28% of individual life insurance sales based on first year annualized premium and

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12% of individual disability sales for the year ended December 31, 2012. We had 1,071 affiliated financial representatives in 29 offices as of December 31, 2012. Although they are independent contractors, we have a close tie with affiliated financial representatives and we offer them benefits, training and access to tools and expertise. To meet the needs of the various marketing channels, particularly the independent brokers, we employ wholesale distributors — Regional Vice Presidents for individual life and Regional Vice Presidents for individual disability. A key differentiator in the nonqualified executive benefit sale is our Regional Vice Presidents — Nonqualified Plans, who are not only wholesalers but also consultants and subject-matter experts providing point-of-sale support in closing cases.

        We market our group life, disability, dental and vision insurance products to small and medium-sized businesses, primarily targeting our sales toward owners and human resources professionals. We sell our group life, disability, dental and vision products in all 50 states and the District of Columbia. We continually adapt our products and pricing to meet local market conditions. We market our fee-for-service capabilities to employers that self-insure their employees' dental, disability and vision benefits. We market our wellness and fee-for-service businesses in all 50 states and the District of Columbia.

        The group insurance market continues to see a shift to voluntary/worksite products due to various pressures on employers. In keeping with this market change, which shifts the funding of such products from the employer to the employee, we continue to place an enhanced focus on our voluntary benefits platform. We believe the voluntary/worksite market presents growth opportunities, and we will continue to develop strategies to capitalize on this expanding market.

        As of December 31, 2012, we had 108 sales representatives and 119 service representatives in 29 offices. Our sales representatives accounted for 96% of our group insurance sales for the year ended December 31, 2012. The group sales force plays a key role in the ongoing servicing of the case by providing local, responsive services to our customers and their brokers, such as renewing contracts, revising plans and solving any administrative issues; communicating the customers' needs and feedback to us and helping employees understand the benefits of their plans.

Corporate Segment

        Our Corporate segment manages the assets representing capital that has not been allocated to any other segment. Financial results of the Corporate segment primarily reflect our financing activities (including interest expense and preferred stock dividends), income on capital not allocated to other segments, inter-segment eliminations, income tax risks and certain income, expenses and other after-tax adjustments not allocated to the segments based on the nature of such items. Results of our exited group medical insurance business are reported in this segment. For further details, see Item 7. "Management's Discussion and Analysis of Financial Condition and Results of Operations — Transactions Affecting Comparability of Results of Operations."

Competition

        Competition in our segments is based on a number of factors including: scale, service, product features, price, investment performance, commission structure, distribution capacity, financial strength ratings and name recognition. We compete with a large number of financial services companies such as banks, mutual funds, broker-dealers, insurers and asset managers. Some of these companies offer a broader array of products, more competitive pricing, greater diversity of distribution sources, better brand recognition or, with respect to insurers, higher financial strength ratings. Some may also have greater financial resources with which to compete or may have better investment performance at various times. We believe we distinguish ourselves from our competitors through our:

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full service platform;



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strong customer relationships;



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focus on financial performance and



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expansive product portfolio.

Ratings

        Insurance companies are assigned financial strength ratings by rating agencies based upon factors relevant to policyholders. Financial strength ratings are generally defined as opinions as to an insurer's financial strength and ability to meet ongoing obligations to policyholders. Information about ratings provides both industry participants and insurance consumers meaningful insights on specific insurance companies. Higher ratings generally indicate financial stability and a stronger ability to pay claims.

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        Principal Life and Principal National Life Insurance Company ("PNLIC") have been assigned the following insurer financial strength ratings:

        A.M. Best's ratings for insurance companies range from "A++" to "S". A.M. Best indicates that "A++" and "A+" ratings are assigned to those companies that in A.M. Best's opinion have superior ability to meet ongoing obligations to policyholders. Fitch's ratings for insurance companies range from "AAA" to "C". Fitch "AA" ratings indicate very strong capacity to meet policyholder and contractholder obligations on a timely basis. Moody's Investors Service ratings for insurance companies range from "Aaa" to "C". Moody's Investors Service indicates that "Aa" ratings are assigned to those companies that have demonstrated excellent financial security. Standard & Poor's ratings for insurance companies range from "AAA" to "R". Standard & Poor's indicates that "A" ratings are assigned to those companies that have demonstrated strong financial security characteristics. In evaluating a company's financial and operating performance, these rating agencies review its profitability, leverage and liquidity, as well as its book of business, the adequacy and soundness of its reinsurance, the quality and estimated market value of its assets, the adequacy of its policy reserves, the soundness of its risk management programs, the experience and competency of its management and other factors. A.M. Best, Fitch, and Standard & Poor's maintain a stable outlook on the U.S. life insurance sector; however, Standard & Poor's indicates it is 'cautious' on maintaining the stable outlook. Moody's has changed its outlook to negative. Regardless of their published outlook on the sector, these rating agencies note that current challenges for the industry are the result of sustained low interest rates, global sovereign uncertainty, equity market volatility, and lingering unemployment and fiscal tightening.

        We believe our strong ratings are an important factor in marketing our products to our distributors and customers, as ratings information is broadly disseminated and generally used throughout the industry. Our ratings reflect each rating agency's opinion of our financial strength, operating performance and ability to meet our obligations to policyholders and are not evaluations directed toward the protection of investors. Such ratings are neither a rating of securities nor a recommendation to buy, hold or sell any security, including our common stock. For more information on ratings, see Item 7. "Management's Discussion and Analysis of Financial Condition and Results of Operations — Liquidity and Capital Resources — Financial Strength Rating and Credit Ratings."

Regulation

        Our businesses are subject to regulation and supervision by U.S. federal and state regulatory authorities as well as non-U.S. regulatory authorities for our operations outside the U.S., which can have a significant effect on our business. Our businesses are also affected by U.S. federal, state and local tax laws as well as tax laws for jurisdictions outside the U.S.

        PFG, our parent holding company, is not licensed as an insurer, investment advisor, broker-dealer, bank or other regulated entity. However, because it is the holding company for all of our operations, it is subject to regulation of our regulated entities, including as an insurance holding company and savings and loan holding company. We are subject to legal and regulatory requirements applicable to public companies, including public reporting and disclosure, securities trading, accounting and financial reporting and corporate governance.

U.S. Insurance Regulation

        We are subject to the insurance holding company laws in the states where our insurance companies are domiciled. Principal Life and PNLIC are domiciled in Iowa and their principal insurance regulatory authority is the Insurance Division of the Department of Commerce of the State of Iowa. Our other U.S. insurance companies are principally regulated by the insurance departments of the states in which they are domiciled. These laws generally require each insurance company directly or indirectly owned by the holding company to register with the insurance department in the insurance company's state of domicile and to furnish financial and other information about the operations of the companies within the holding company system. Transactions affecting the insurers in the holding company system must be fair and at arm's length. Most states have insurance laws that require regulatory approval of a direct or indirect change in control of an insurer or an insurer's holding company and laws requiring prior notification of state insurance departments of a change in control of a non-domiciliary insurance company doing business in that state.

        Annually, our U.S. insurance companies must submit an opinion from a board-appointed qualified actuary to state insurance regulators, where licensed, on whether the statutory assets held backing statutory reserves are sufficient to meet contractual obligations and related expenses of the insurer. If such an opinion cannot be rendered noting the sufficiency of assets, then the insurance company must set up additional statutory reserves drawing from available statutory surplus until such an opinion can be given.

        State insurance departments have broad administrative powers over the insurance business, including insurance company licensing and examination, agent licensing, establishment of reserve requirements and solvency standards,

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premium rate regulation, admittance of assets to statutory surplus, policy form approval, unfair trade and claims practices regulation and other matters. State insurance statutes also typically place restrictions and limitations on the amount of dividends or other distributions payable by insurance company subsidiaries to their parent companies. See Item 7. "Management's Discussion and Analysis of Financial Condition and Results of Operations — Liquidity and Capital Resources" for further details.

        In order to enhance the regulation of insurer solvency, the National Association of Insurance Commissioners ("NAIC") has established risk-based capital standards. The standards require life insurers to submit a report to state regulators on an annual basis regarding their risk-based capital based upon four categories of risk: asset risk, insurance risk, interest rate risk and business risk. As of December 31, 2011, the statutory surplus of each of our U.S. life insurance companies exceeded the minimum level of risk-based capital requirements required before state insurance departments would take action against an insurer.

        State and federal insurance and securities regulatory authorities and other state law enforcement agencies and attorneys general regularly make inquiries and conduct examinations or investigations regarding our compliance with, among other things, insurance laws and securities laws.

        Each state has insurance guaranty association laws under which insurers doing business in a state can be assessed, up to prescribed limits, in order to cover contractual benefit obligations of insolvent insurance companies. The guaranty associations levy assessments on each member insurer in a jurisdiction on the basis of the proportionate share of the premiums written by such insurer in the lines of business in which the insolvent insurer is engaged. Some jurisdictions permit the member insurers to recover the assessments paid through full or partial premium tax offsets.

Securities Regulation

        Insurance and investment products such as variable annuities, variable life insurance and some funding agreements that constitute securities and mutual fund products are subject to securities laws and regulations, including state securities regulation as well as federal regulation under the SEC, the Financial Industry Regulatory Authority and other regulatory authorities. These regulations affect investment advice, sales and related activities for these products.

        We also have entities which are registered as investment advisers with the SEC under the Investment Advisers Act of 1940.

Employee Retirement Income Security Act

        As we provide products and services for U.S. employee benefit plans, we are subject to regulation under the Employee Retirement Income Security Act ("ERISA"). ERISA provisions include reporting and disclosure requirements and standards of conduct.

Banking Regulation

        Principal Bank, a wholly owned subsidiary, is a federal savings bank regulated by the Office of the Comptroller of the Currency. Principal Bank is also a member of the Federal Deposit Insurance Corporation ("FDIC") and subject to its regulations. In July 2011, we became subject to oversight from and examination by the Federal Reserve Board ("Federal Reserve") pursuant to the Dodd-Frank Wall Street Reform and Consumer Protection Act ("Dodd-Frank Act"). This oversight includes all entities within the PFG family. Due to our ownership of Principal Bank, we are classified under federal banking law as a savings and loan holding company ("SLHC"). The Federal Reserve has adopted a procedure for deregistration as a SLHC for companies seeking to avail themselves of an exemption included within the Dodd-Frank Act. We intend to submit an application to the Federal Reserve to deregister as a SLHC. For more information, see Item 1A. "Risk Factors — Changes in laws, regulations or accounting standards may reduce our profitability — Financial services regulatory reform may reduce our profitability, impact how we do business or limit our ability to engage in certain capital expenditures."

Environmental Regulation

        As we own and operate real property, we are subject to federal, state and local environmental laws and could be subject to environmental liabilities and costs associated with required remediation of our properties. We routinely have environmental assessments performed for real estate being acquired or used as collateral for commercial mortgages we use for investment.

Regulation of International Businesses

        Our international businesses are supervised by regulatory authorities in the jurisdictions in which they operate.

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Risk Management

        Like all financial services companies, we are exposed to a wide variety of financial, operational and other risks, as described in Item 1A. "Risk Factors." Effective enterprise risk management is, therefore, a key component of our business model. Enterprise risk management helps us to:

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identify and manage those risks that present profitable growth opportunities, and avoid those that do not and



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balance the sometimes competing demands of our various stakeholders, meet our customer obligations, satisfy regulatory requirements and optimize shareholder returns relative to the risks we take.

        We utilize an integrated risk management framework to help us identify, assess, monitor, report and manage our risks within established limits and risk tolerances. The framework delivers important perspective that is used in strategic and tactical decision making and is adaptable to changes in our businesses and in the external environments in which we operate. Our approach also requires a commitment to continuous improvement and periodic validation.

        Our governance structure includes Board of Director oversight, internal risk committees, a corporate risk area and embedded risk professionals in all of our business units and functional areas. Our Board of Directors, Audit Committee, Finance Committee, Human Resource Committee and Nominating and Governance Committee provide oversight no less frequently than quarterly addressing various aspects and assessments of our risk profile. Quarterly reports on risk topics and an annual enterprise-wide risk report are provided to the Board of Directors by the Chief Risk Officer.

        Our internal risk committees meet on a regular and frequent basis to discuss various issues and reflect on profile status. Each business unit and key functional area has its own risk committee that is responsible for oversight of all risks within the unit. Quite often, these committees include key corporate leaders. We are also deploying committees that provide oversight around a certain risk or group of related risks across the organization. This matrix approach helps us maintain comprehensive risk coverage and preserve an integrated view of risks. Two committees reside at the top of our internal risk committee hierarchy. The Corporate Strategic Working Group provides enterprise-wide oversight around our strategic risk profile and the Enterprise Risk Management Committee, comprised of members from corporate senior management, exercises enterprise-wide oversight around all other risk profiles.

        The business units and functional areas are responsible for identifying, assessing, monitoring, reporting and managing their own risks. Risk professionals embedded within each business unit help align risk management practice with the strategies of the unit as well as enterprise-wide objectives. The Chief Risk Officer and supporting staff are separate from the business units and provide objective oversight, framework enablement and aggregated risk analysis. Internal Audit provides independent assurance around effective risk management design and control execution.

        We have established risk tolerances from an overall corporate perspective, a business unit perspective, and for specific categories of risks. We monitor a variety of risk metrics on an ongoing basis and make any necessary adjustments to help us stay within our established risk tolerances. Potentially significant actions are considered in terms of the possible impact on our risk profile, including but not limited to the capital required, the impact on near term and long-term earnings and the ability to meet our targets with respect to return on equity, liquidity, debt/capital, cash coverage and operational risk. Quarterly risk reporting provides a feedback loop between the business units and the Chief Risk Officer and includes, among other things, emerging risk outlooks or incident reporting, if necessary. We have developed a Business Continuity Management Program that identifies critical business functions and includes plans for their protection and recovery in the event of a disaster or other business interruption.

        We regularly build upon our already strong risk management practices to incorporate updated modeling tools, processes and metrics, which we actively use to better understand and manage our business.

Employees

        As of December 31, 2012, we had 13,373 employees. None of our employees are subject to collective bargaining agreements governing employment with us. We believe that our employee relations are satisfactory.

Internet Website

        Our Internet website can be found at www.principal.com. We make available free of charge on or through our Internet website, access to our annual report on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K and amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Securities Exchange Act of 1934 as soon as reasonably practicable after such material is filed with or furnished to the SEC. Also available free of charge on our Internet website is our code of business conduct and ethics, corporate governance guidelines and charters for the Audit, Finance, Human Resources and Nominating and Governance committees of our Board of Directors. Also see Item 10. "Directors, Executive Officers and Corporate Governance."

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Item 1A.    Risk Factors

        This section provides an overview of the risks that may impact our performance in the future.

Adverse capital and credit market conditions may significantly affect our ability to meet liquidity needs, as well as our access to capital and cost of capital.

        Our results of operations, financial condition, cash flows and statutory capital position could be materially adversely affected by continued volatility, uncertainty and disruption in the capital and credit markets.

        We maintain a level of cash and securities which, combined with expected cash inflows from investments and operations, is believed adequate to meet anticipated short-term and long-term benefit and expense payment obligations. However, withdrawal and surrender levels may differ from anticipated levels for a variety of reasons, such as changes in economic conditions or changes in our claims paying ability and financial strength ratings. For additional information regarding our exposure to interest rate risk and the impact of a downgrade in our financial strength ratings, see "— Changes in interest rates or credit spreads may adversely affect our results of operations, financial condition and liquidity, and our net income can vary from period-to-period" and "— A downgrade in our financial strength or credit ratings may increase policy surrenders and withdrawals, reduce new sales and terminate relationships with distributors, impact existing liabilities and increase our cost of capital, any of which could adversely affect our profitability and financial condition." In the event our current internal sources of liquidity do not satisfy our needs, we may have to seek additional financing and, in such case, we may not be able to successfully obtain additional financing on favorable terms, or at all. The availability of additional financing will depend on a variety of factors such as market conditions, the general availability of credit, the volume of trading activities, the overall availability of credit to the financial services industry, our credit ratings and credit capacity, as well as customers' or lenders' perception of our long- or short-term financial prospects. Similarly, our access to funds may be impaired if regulatory authorities or rating agencies take negative actions against us.

        Disruptions, uncertainty or volatility in the capital and credit markets may limit our access to capital required to operate our business, most significantly our insurance operations. Such market conditions may limit our ability to replace, in a timely manner, maturing liabilities; satisfy statutory capital requirements; fund redemption requests on insurance or other financial products; generate fee income and market-related revenue to meet liquidity needs and access the capital necessary to grow our business. As such, we may be forced to delay raising capital, issue shorter tenor securities than we prefer, utilize available internal resources or bear an unattractive cost of capital, which could decrease our profitability and significantly reduce our financial flexibility and liquidity.

        For further discussion on liquidity risk management, see Item 7. "Management's Discussion and Analysis of Financial Condition and Results of Operations — Liquidity and Capital Resources."

Continued difficult conditions in the global capital markets and the economy generally may materially and adversely affect our business and results of operations.

        Our results of operations are materially affected by conditions in the global capital markets and the economy generally, both in the U.S. and elsewhere around the world. Recently, concerns over the slow economic recovery, level of U.S. national debt and structural deficits, European sovereign debt crisis, the U.S. mortgage market, inflation levels, energy costs and geopolitical issues have contributed to increased volatility and diminished expectations for the economy and the markets going forward. These factors, combined with volatile oil prices, reduced business and consumer confidence and continued high unemployment, have negatively impacted the U.S. economy. Initially, the concerns on the part of market participants were focused on the subprime segment of the mortgage-backed securities market. However, these concerns expanded to include a broad range of mortgage- and asset-backed and other fixed income securities, including those rated investment grade, the U.S. and international credit and interbank money markets, generally, and a wide range of financial institutions and markets, asset classes and sectors. Although liquidity has improved, the market for fixed income instruments has continued to experience some price volatility, credit downgrade events and elevated probabilities of default. Our AUM and revenues may decline in such circumstances and our profit margins could erode. In addition, in the event of extreme prolonged market events, such as the global credit crisis, we could incur significant losses. Even in the absence of a market downturn, we are exposed to substantial risk of loss due to market volatility.

        Factors such as consumer spending, business investment, government spending, the volatility and strength of the capital markets, investor and consumer confidence and inflation levels all affect the business and economic environment and, ultimately, the amount and profitability of our business. In an economic downturn characterized by higher unemployment, lower family income, lower corporate earnings, lower business investment, negative investor sentiment and lower consumer spending, the demand for our financial and insurance products could be adversely affected. In addition, we may experience an elevated incidence of claims and lapses or surrenders of policies. Our policyholders may choose to defer paying insurance premiums or stop paying insurance premiums altogether. In addition, reductions in employment levels of our existing employer customers may result in a reduction in membership levels and premium income for our specialty benefits products. Participants within the retirement plans for which we provide administrative services may elect to reduce or stop their payroll deferrals to these plans, which would reduce AUM and revenues. In addition, reductions in employment levels may result in a decline in employee deposits into retirement plans. Adverse

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changes in the economy could affect net income negatively and could have a material adverse effect on our business, results of operations and financial condition.

Continued volatility or further declines in the equity markets could reduce our AUM and may result in investors withdrawing from the markets or decreasing their rates of investment, all of which could reduce our revenues and net income.

        Domestic and international equity markets experienced severe declines and heightened volatility in 2008 and early 2009. Because the revenues of our asset management and accumulation businesses are, to a large extent, based on the value of AUM, a decline in domestic and global equity markets will decrease our revenues. Turmoil in these markets could lead investors to withdraw from these markets, decrease their rates of investment or refrain from making new investments, which may reduce our net income, revenues and AUM.

        For further discussion on equity risk management, see Item 7A. "Quantitative and Qualitative Disclosures About Market Risk — Equity Risk."

Changes in interest rates or credit spreads may adversely affect our results of operations, financial condition and liquidity, and our net income can vary from period-to-period.

        We are exposed to significant financial and capital markets risk, including changes in interest rates, credit spreads, equity prices, real estate values, foreign currency exchange rates, market volatility, the performance of the economy in general, the performance of the specific obligors included in our portfolio and other factors outside our control. Our exposure to interest rate risk relates primarily to the market price and cash flow variability associated with changes in interest rates. A rise in interest rates would increase unrealized losses in our investment portfolio and, if long-term interest rates rise dramatically within a six to twelve month time period, certain segments of our life insurance and annuities businesses may be exposed to disintermediation risk. Disintermediation risk refers to the risk that our policyholders may surrender their contracts in a rising interest rate environment, requiring us to liquidate assets in an unrealized loss position. Due to the long-term nature of the liabilities associated with certain segments of our life insurance businesses, sustained declines in long-term interest rates may subject us to reinvestment risks and increased hedging costs. In other situations, declines in interest rates may result in increasing the duration of certain life insurance liabilities, creating asset and liability duration mismatches.

        Our investment portfolio also contains interest rate sensitive instruments, such as fixed income securities, which may be adversely affected by changes in interest rates from governmental monetary policies, domestic and international economic and political conditions and other factors beyond our control. A rise in interest rates would increase unrealized losses in our investment portfolio, offset by our ability to earn higher rates of return on funds reinvested. Conversely, a decline in interest rates would decrease the net unrealized loss position of our investment portfolio, offset by lower rates of return on funds reinvested. Although we take measures to manage the economic risks of investing in a changing interest rate environment, we may not be able to mitigate the interest rate risk of our assets relative to our liabilities.

        Our exposure to credit spreads primarily relates to market price variability and reinvestment risk associated with changes in credit spreads. A widening of credit spreads would increase unrealized losses in our investment portfolio, would increase losses associated with credit-based derivatives we have sold that do not qualify or have not been designated for hedge accounting where we assume credit exposure and, if issuer credit spreads increase as a result of fundamental credit deterioration, would likely result in higher other-than-temporary impairments. Credit spread tightening will reduce net investment income associated with new purchases of fixed maturities. Credit spread tightening may also cause an increase in the reported value of certain liabilities that are valued using a discount rate that reflects our own credit spread. In addition, market volatility may make it difficult to value certain of our securities if trading becomes less frequent. As such, valuations may include assumptions or estimates that may have significant period-to-period changes from market volatility, which could have a material adverse effect on our results of operations or financial condition. Continuing challenges include continued weakness in the U.S. residential and commercial real estate market and increased mortgage delinquencies, investor anxiety over the U.S. economy, rating agency downgrades of various structured products and financial issuers, unresolved issues with structured investment vehicles and monolines, deleveraging of financial institutions and hedge funds and a serious dislocation in the inter-bank market. If significant, continued volatility, changes in interest rates, changes in credit spreads and defaults, a lack of pricing transparency, market liquidity, declines in equity prices, declines in inflation-adjusted investments and the strengthening or weakening of foreign currencies against the U.S. dollar, individually or in tandem, could continue to have a material adverse effect on our results of operations, financial condition or cash flows through realized losses, impairments and changes in unrealized positions.

Our investment portfolio is subject to several risks that may diminish the value of our invested assets and the investment returns credited to customers, which could reduce our sales, revenues, AUM and net income.

An increase in defaults or write-downs on our fixed maturities portfolio may reduce our profitability.

        We are subject to the risk that the issuers of the fixed maturities we own will default on principal and interest payments, particularly if a major downturn in economic activity occurs. As of December 31, 2012, our U.S. investment operations held $47.9 billion of fixed maturities, or 77% of total U.S. invested assets, of which approximately 7% were

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below investment grade, including $605.6 million, or 1.27% of our total fixed maturities which we classified as either "problem," "potential problem" or "restructured." See Item 7. "Management's Discussion and Analysis of Financial Condition and Results of Operations — Investments — U.S. Investment Operations — Fixed Maturities."

        Our U.S. fixed maturities portfolio includes securities collateralized by residential and commercial mortgage loans. As of December 31, 2012, our U.S. investment operations held $4.4 billion of residential mortgage-backed securities, of which $3.3 billion are Government National Mortgage Association, Federal National Mortgage Association or Federal Home Loan Mortgage Corporation pass-through securities, and $3.9 billion of commercial mortgage-backed securities, which represent in combination 17% of our total fixed maturities portfolio. For residential mortgage-backed securities, prepayment speeds, changes in mortgage delinquency or recovery rates, credit rating changes by rating agencies, changes in property values underlying the loans and the quality of service provided by service providers on securities in our portfolios could lead to write-downs on these securities. For commercial mortgage-backed securities, changes in mortgage delinquency or default rates, interest rate movements, credit quality and vintage of the underlying loans, changes in property values underlying the loans and credit rating changes by rating agencies could result in write-downs of those securities. See Item 7. "Management's Discussion and Analysis of Financial Condition and Results of Operations — Investments — U.S. Investment Operations — Fixed Maturities."

        As of December 31, 2012, the international investment operations of our fully consolidated subsidiaries held $3.7 billion of fixed maturities, or 62%, of total international invested assets, of which 18% are government bonds. Some non-government bonds have been rated on the basis of the issuer's country credit rating. However, the ratings relationship between national ratings and global ratings is not linear with the U.S. The starting point for national ratings differs by country, which makes the assessment of credit quality more difficult. See Item 7. "Management's Discussion and Analysis of Financial Condition and Results of Operations — Investments — International Investment Operations." An increase in defaults on our fixed maturities portfolio could harm our financial strength and reduce our profitability.

An increased rate of delinquency and defaults on our commercial mortgage loans, including balloon maturities with and without amortizing payments, may adversely affect our profitability.

        Our commercial mortgage loan portfolio faces both delinquency and default risk. Commercial mortgage loans of $10.2 billion, of which no loans were in the process of foreclosure, represented 15% of our total invested assets as of December 31, 2012. The performance of our commercial mortgage loan investments, however, may fluctuate in the future. An increase in the delinquency rate of, and defaults under, our commercial mortgage loan portfolio could harm our financial strength and decrease our profitability.

        As of December 31, 2012, approximately $8.3 billion, or 82%, of our commercial mortgage loans before valuation allowance had balloon payment maturities. A balloon maturity is a loan with all or a meaningful portion of the loan amount due at the maturity of the loan. The default rate on commercial mortgage loans with balloon payment maturities has historically been higher than for commercial mortgage loans with a fully amortizing loan structure. Since most of the principal is repaid at maturity, the amount of loss on a default is generally greater than fully amortizing commercial mortgage loans. An increase in defaults on balloon maturity loans as a result of the foregoing factors could harm our financial strength and decrease our profitability.

Mark-to-market adjustments on certain equity method investments and trading securities may reduce our profitability or cause volatility in our reported earnings.

        Our investment portfolio includes certain equity method investments and trading securities that are reported at fair value on the consolidated statements of financial position, with changes in fair value reported in net investment income on the consolidated statements of operations. Mark-to-market adjustments on these investments may reduce our profitability or cause our net income to vary from period to period. We anticipate that acquisition and investment activities may increase the number and magnitude of these investments in the future.

We may have difficulty selling our privately placed fixed maturities, commercial mortgage loans and real estate investments because they are less liquid than our publicly traded fixed maturities.

        We hold certain investments that may lack liquidity, such as privately placed fixed maturities, commercial mortgage loans and real estate investments. These asset classes represented approximately 39% of the value of our invested assets as of December 31, 2012.

        If we require significant amounts of cash on short notice, we may have difficulty selling these investments in a timely manner, be forced to sell them for less than we otherwise would have been able to realize or both. The reported value of our relatively illiquid types of investments, our investments in the asset classes described above and, at times, our high quality, generally liquid asset classes, do not necessarily reflect the lowest possible price for the asset. If we were forced to sell certain of our assets in the current market, there can be no assurance that we will be able to sell them for the prices at which we have recorded them and we may be forced to sell them at significantly lower prices.

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The impairment of other financial institutions could adversely affect us.

        We use derivative instruments to hedge various risks we face in our businesses. See Item 7A. "Quantitative and Qualitative Disclosures About Market Risk." We enter into a variety of derivative instruments, including interest rate swaps, interest rate collars, swaptions, interest rate futures, currency swaps, currency forwards, currency options, equity options, equity futures, credit default swaps and total return swaps, with a number of counterparties in the financial services industry, including brokers and dealers, commercial banks, investment banks and other investment funds and other institutions. For transactions where we are in-the-money, we are exposed to credit risk in the event of default of our counterparty. We establish collateral agreements with nominal thresholds for a large majority of our counterparties to limit our exposure. However, our credit risk may be exacerbated when the collateral held by us cannot be realized or is liquidated at prices not sufficient to recover the full amount of the loan or derivative exposure. With regard to our derivative exposure, we have over-collateralization requirements on the portion of collateral we hold, based on the risk profile of the assets posted as collateral. We also have exposure to these financial institutions in the form of unsecured debt instruments and equity investments. Such losses or impairments to the carrying value of these assets may materially and adversely affect our business and results of operations.

Our requirements to post collateral or make payments related to declines in market value of specified assets may adversely affect our liquidity and expose us to counterparty credit risk.

        Many of our derivative transactions with financial and other institutions specify the circumstances under which the parties are required to post collateral. The amount of collateral we may be required to post under these agreements may increase under certain circumstances, which could adversely affect our liquidity. In addition, under the terms of some of our transactions we may be required to make payment to our counterparties related to any decline in the market value of the specified assets. Such payments could have an adverse effect on our liquidity. Furthermore, with respect to any such payments, we will have unsecured risk to the counterparty as these amounts are not required to be segregated from the counterparty's other funds, are not held in a third-party custodial account, and are not required to be paid to us by the counterparty until the termination of the transaction.

Environmental liability exposure may result from our commercial mortgage loan portfolio and real estate investments.

        Liability under environmental protection laws resulting from our commercial mortgage loan portfolio and real estate investments may harm our financial strength and reduce our profitability. Under the laws of several states, contamination of a property may give rise to a lien on the property to secure recovery of the costs of cleanup. In some states, this kind of lien has priority over the lien of an existing mortgage against the property, which would impair our ability to foreclose on that property should the related loan be in default. In addition, under the laws of some states and under the federal Comprehensive Environmental Response, Compensation and Liability Act of 1980, we may be liable for costs of addressing releases or threatened releases of hazardous substances that require remedy at a property securing a mortgage loan held by us, if our agents or employees have become sufficiently involved in the hazardous waste aspects of the operations of the related obligor on that loan, regardless of whether or not the environmental damage or threat was caused by the obligor. We also may face this liability after foreclosing on a property securing a mortgage loan held by us. This may harm our financial strength and decrease our profitability.

Regional concentration of our commercial mortgage loan portfolio in California may subject us to economic downturns or losses attributable to earthquakes in that state.

        Commercial mortgage lending in the state of California accounted for 20%, or $2.0 billion, of our commercial mortgage loan portfolio as of December 31, 2012. Due to this concentration of commercial mortgage loans in California, we are exposed to potential losses resulting from the risk of an economic downturn in California as well as to catastrophes, such as earthquakes, that may affect the region. While we generally do not require earthquake insurance for properties on which we make commercial mortgage loans, we do take into account property specific engineering reports, construction type and geographical concentration by fault lines in our investment underwriting guidelines. If economic conditions in California do not improve or continue to deteriorate or catastrophes occur, we may in the future experience delinquencies or defaults on the portion of our commercial mortgage loan portfolio located in California, which may harm our financial strength and reduce our profitability.

Our valuation of fixed maturities, equity securities and derivatives may include methodologies, estimations and assumptions which are subject to differing interpretations and could result in changes to investment valuations that may materially adversely affect our results of operations or financial condition.

        Fixed maturities, equity securities and derivatives reported at fair value on our consolidated statements of financial position represented the majority of our total cash and invested assets. The fair value hierarchy prioritizes the inputs to valuation techniques used to measure fair value into three levels. The level in the fair value hierarchy is based on the priority of the inputs to the respective valuation technique. The fair value hierarchy gives the highest priority to quoted prices in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3). An asset or liability's classification within the fair value hierarchy is based on the lowest level of significant input to its valuation.

•

Level 1: Fair values are based on unadjusted quoted prices in active markets for identical assets or liabilities.

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•

Level 2: Fair values are based on inputs other than quoted prices within Level 1 that are observable for the asset or liability, either directly or indirectly.



•

Level 3: Fair values are based on at least one significant unobservable input for the asset or liability.

        Excluding separate account assets as of December 31, 2012, 2%, 97% and 1% of our net assets and liabilities reported at fair value represented Level 1, Level 2 and Level 3, respectively. Our Level 1 assets and liabilities primarily include exchange traded equity securities, mutual funds and U.S. Treasury bonds. Our Level 2 assets and liabilities primarily include fixed maturities (including public and private bonds), equity securities, over-the-counter derivatives and other investments for which public quotations are not available but that are priced by third-party pricing services or internal models using substantially all observable inputs. Our Level 3 assets and liabilities include certain fixed maturities, private equity securities, commercial mortgage loan investments and obligations of consolidated variable interest entities for which the fair value option was elected, complex derivatives, embedded derivatives and an equity method real estate investment for which the fair value option was elected. Level 3 securities contain at least one significant unobservable market input and as a result considerable judgment may be used in determining the fair values. These fair values are generally obtained through the use of valuation models or methodologies using at least one significant unobservable input or broker quotes. Prices provided by independent pricing services or independent broker quotes that are used in the determination of fair value can vary for a particular security.

        For additional information on our valuation methodology, see Item 8. "Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 14, Fair Value Measurements."

        During periods of market disruption including periods of significantly rising or high interest rates, rapidly widening credit spreads or illiquidity, it may be difficult to value certain of our securities, for example collateralized mortgage obligations and collateralized debt obligations, if trading becomes less frequent and/or market data becomes less observable. There may be certain asset classes that were in active markets with significant observable data that become illiquid due to the current financial environment. In such cases, more securities may fall to Level 3 and thus require more subjectivity and management judgment. As such, valuations may include inputs and assumptions that are less observable or require greater estimation as well as valuation methods that require greater estimation, which could result in values that are different from the value at which the investments may be ultimately sold. Further, rapidly changing credit and equity market conditions could materially impact the valuation of securities as reported within our consolidated financial statements and the period-to-period changes in value could vary significantly. Decreases in value may have a material adverse effect on our results of operations or financial condition.

The determination of the amount of allowances and impairments taken on our investments requires estimations and assumptions which are subject to differing interpretations and could materially impact our results of operations or financial position.

        The determination of the amount of allowances and impairments vary by investment type and is based upon our periodic evaluation and assessment of known and inherent risks associated with the respective asset class. Such evaluations and assessments are revised as conditions change and new information becomes available. There can be no assurance that our management has accurately assessed the level of impairments taken and allowances reflected in our financial statements. Furthermore, additional impairments may need to be taken or allowances provided for in the future. Historical trends may not be indicative of future impairments or allowances.

        Additionally, our management considers a wide range of factors about the instrument issuer and uses their best judgment in evaluating the cause of the decline in the estimated fair value of the instrument and in assessing the prospects for recovery. Inherent in management's evaluation of the security are assumptions and estimates about the operations of the issuer and its future earnings potential. For further information regarding our impairment methodology, see Item 7. "Management's Discussion and Analysis of Financial Condition and Results of Operations — Investments — U.S. Investment Operations — Fixed Maturities."

Any impairments of or valuation allowances against our deferred tax assets in the future could adversely affect our results of operations and financial condition.

        Deferred tax liabilities and assets are determined based on the difference between the financial statement and tax bases of assets and liabilities using enacted tax rates expected to be in effect during the years in which the basis differences reverse. We are required to evaluate the recoverability of our deferred tax assets each quarter and establish a valuation allowance, if necessary, to reduce our deferred tax assets to an amount that is more-likely-than-not to be realizable. In determining the need for a valuation allowance, we consider many factors, including future reversals of existing taxable temporary differences, future taxable income exclusive of reversing temporary differences and carryforwards, taxable income in prior carryback years and implementation of any feasible and prudent tax planning strategies management would employ to realize the tax benefit.

        Inherent in the provision for income taxes are estimates regarding the deductibility of certain items, the timing of income and expense recognition and the current or future realization of operating losses, capital losses and certain tax credits. In the event these estimates differ from our prior estimates due to the receipt of new information, we may be required to significantly change the provision for income taxes recorded in the consolidated financial statements. Any

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such change could significantly affect the amounts reported in the consolidated financial statements in the year these estimates change. A further significant decline in value of assets incorporated into our tax planning strategies could lead to an increase of our valuation allowance on deferred tax assets having an adverse effect on current and future results.

Gross unrealized losses may be realized or result in future impairments, resulting in a reduction in our net income.

        Fixed maturities that are classified as available-for-sale ("AFS") are reported on the consolidated statements of financial position at fair value. Unrealized gains or losses on AFS securities are recognized as a component of equity and are, therefore, excluded from net income. Our U.S. investment operations held gross unrealized losses on fixed maturities of $0.8 billion pre-tax as of December 31, 2012, and the component of gross unrealized losses for securities trading down 20% or more for over six months was approximately $0.7 billion pre-tax. The accumulated change in fair value of the AFS securities is recognized in net income when the gain or loss is realized upon the sale of the asset or in the event that the decline in fair value is determined to be other than temporary (referred to as an other-than-temporary impairment). Realized losses or impairments may have a material adverse impact on our net income in a particular quarterly or annual period.

Competition from companies that may have greater financial resources, broader arrays of products, higher ratings and stronger financial performance may impair our ability to retain existing customers, attract new customers and maintain our profitability.

        We believe that our ability to compete is based on a number of factors including scale, service, product features, price, investment performance, commission structure, distribution capacity, financial strength ratings and name recognition. We compete with a large number of financial services companies such as banks, mutual funds, broker-dealers, insurers and asset managers, many of which have advantages over us in one or more of the above competitive factors.

        Each of our segments faces strong competition. The primary competitors for our Retirement and Investor Services and Principal Global Investors segments are asset managers, banks, broker-dealers and insurers. Our ability to increase and retain AUM is directly related to the performance of our investments as measured against market averages and the performance of our competitors. Even when securities prices are generally rising, performance can be affected by investment styles. Also, there is a risk that we may not be able to attract and retain the top talent needed to compete in our industry.

        Competition for our Principal International segment comes primarily from local financial services firms and other international companies operating on a stand-alone basis or in partnership with local firms.

        Our U.S. Insurance Solutions segment competes with insurers.

        National banks, with their large existing customer bases, may increasingly compete with insurers as a result of court rulings allowing national banks to sell annuity products in some circumstances, and as a result of legislation removing restrictions on bank affiliations with insurers. Specifically, the Gramm-Leach-Bliley Act of 1999 permits mergers that combine commercial banks, insurers and securities firms under one holding company. These developments may increase competition, in particular for our asset management and accumulation businesses, by substantially increasing the number, size and financial strength of potential competitors who may be able to offer, due to economies of scale, more competitive pricing than we can.

        In response to current market conditions, the U.S. and foreign governments in the markets we serve have taken actions, including but not limited to, direct government control or investment in certain entities. We may find that these actions create, among other things, unforeseen competitive advantages for our competitors due to explicit or implied support from the government.

We may not be able to protect our intellectual property and may be subject to infringement claims.

        We rely on a combination of contractual rights and copyright, trademark, patent and trade secret laws to establish and protect our intellectual property. Although we use a broad range of measures to protect our intellectual property rights, third parties may infringe or misappropriate our intellectual property. We may have to litigate to enforce and protect our copyrights, trademarks, patents, trade secrets and know-how or to determine their scope, validity or enforceability, which represents a diversion of resources that may be significant in amount and may not prove successful. The loss of intellectual property protection or the inability to secure or enforce the protection of our intellectual property assets could have a material adverse effect on our business and our ability to compete.

        We also may be subject to costly litigation in the event that another party alleges our operations or activities infringe upon such other party's intellectual property rights. Third parties may have, or may eventually be issued, patents or other protections that could be infringed by our products, methods, processes or services or could otherwise limit our ability to offer certain product features. Any party that holds such a patent could make a claim of infringement against us. We may also be subject to claims by third parties for breach of copyright, trademark, license usage rights, or misappropriation of trade secret rights. Any such claims and any resulting litigation could result in significant liability for damages. If we were found to have infringed or misappropriated a third party patent or other intellectual property rights, we could incur substantial liability, and in some circumstances could be enjoined from providing certain products or services to our

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customers or utilizing and benefiting from certain methods, processes, copyrights, trademarks, trade secrets or licenses, or alternatively could be required to enter into costly licensing arrangements with third parties, all of which could have a material adverse effect on our business, results of operations and financial condition.

A downgrade in our financial strength or credit ratings may increase policy surrenders and withdrawals, reduce new sales and terminate relationships with distributors, impact existing liabilities and increase our cost of capital, any of which could adversely affect our profitability and financial condition.

        A.M. Best, Fitch, Moody's Investors Services and Standard & Poor's publish financial strength ratings on U.S. life insurance companies that are indicators of an insurance company's ability to meet contractholder and policyholder obligations. These rating agencies also assign credit ratings on non-life insurance entities, such as PFG and Principal Financial Services, Inc. ("PFS"). Credit ratings are indicators of a debt issuer's ability to meet the terms of debt obligations in a timely manner, and are important factors in overall funding profile and ability to access external capital.

        Ratings are important factors in establishing the competitive position of insurance companies and maintaining public confidence in products being offered. A ratings downgrade, or the potential for such a downgrade, could, among other things:

•

materially increase the number of surrenders for all or a portion of the net cash values by the owners of policies, contracts and general account GICs we have issued, and materially increase the number of withdrawals by policyholders of cash values from their policies;



•

result in the termination of our relationships with broker-dealers, banks, agents, wholesalers and other distributors of our products and services;



•

reduce new sales, particularly with respect to general account GICs and funding agreements purchased by pension plans and other institutions;



•

cause some of our existing liabilities to be subject to acceleration, additional collateral support, changes in terms, or creation of additional financial obligations and



•

increase our cost of capital and limit our access to the capital markets.

        Any of these consequences could adversely affect our profitability and financial condition.

Our efforts to reduce the impact of interest rate changes on our profitability and retained earnings may not be effective.

        We attempt to significantly reduce the impact of changes in interest rates on the profitability and retained earnings of our asset accumulation and insurance operations. We accomplish this reduction primarily by managing the duration of our assets relative to the duration of our liabilities. During a period of rising interest rates, policy surrenders, withdrawals and requests for policy loans may increase as customers seek to achieve higher returns. Despite our efforts to reduce the impact of rising interest rates, we may be required to sell assets to raise the cash necessary to respond to such surrenders, withdrawals and loans, thereby realizing capital losses on the assets sold. Because volatile interest rates and credit spreads often make it more difficult to sell certain fixed income securities, there is also a risk that we will find it difficult to raise the cash necessary to fund a very large amount of withdrawal activity. An increase in policy surrenders and withdrawals may also require us to accelerate amortization of deferred policy acquisition costs ("DPAC") relating to these contracts, which would further reduce our profitability.

        During periods of declining interest rates, borrowers may prepay or redeem mortgages and bonds that we own, which would force us to reinvest the proceeds at lower interest rates. For some of our products, such as GICs and funding agreements, we are unable to lower the rate we credit to customers in response to the lower return we will earn on our investments. In addition, it may be more difficult for us to maintain our desired spread between the investment income we earn and the interest we credit to our customers during periods of declining interest rates, thereby reducing our profitability. Interest rates are currently at historically low levels. Interest rates have remained low over a sustained period of time, putting additional pressure on our spreads. Primarily as a result of lower interest rates, we had an unlocking of DPAC and other actuarial balances in 2012 that decreased net income by $96.7 million and continued lower interest rates could potentially result in increases in reserves.

        For further discussion on interest rate risk management, see Item 7A. "Quantitative and Qualitative Disclosures About Market Risk — Interest Rate Risk."

Guarantees within certain of our products that protect policyholders may decrease our earnings or increase the volatility of our results of operations or financial position under U.S. generally accepted accounted principles ("U.S. GAAP") if our hedging or risk management strategies prove ineffective or insufficient.

        Certain of our variable annuity products include guaranteed minimum death benefits and/or guaranteed minimum withdrawal benefits. Periods of significant and sustained downturns in equity markets, increased equity volatility or reduced interest rates could result in an increase in the valuation of the future policy benefit or policyholder account balance liabilities associated with such products, resulting in a reduction to net income. We use derivative instruments to mitigate changes in the liability exposure related to interest rate, equity market and volatility movements, and the

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volatility of net income associated with these liabilities. While we believe that these and other actions have mitigated the overall economic risks related to these benefits, we remain liable for the guaranteed benefits in the event that derivative counterparties are unable or unwilling to pay. The liability exposure and volatility of net income may also be influenced by changes in market credit spreads reflecting our own creditworthiness, for which we do not attempt to hedge. In addition, we are subject to the risk that hedging and other management procedures prove ineffective or that unanticipated policyholder behavior or mortality, combined with adverse market events, produces economic losses beyond the scope of the risk management techniques employed. These, individually or collectively, may have a material adverse effect on net income, financial condition or liquidity. We are also subject to the risk that the cost of hedging these guaranteed minimum benefits increases as implied volatilities increase and/or interest rates decrease, resulting in a reduction to net income.

If we are unable to attract and retain qualified employees and sales representatives and develop new distribution sources, our results of operations, financial condition and sales of our products may be adversely impacted.

        Our continued success is largely dependent on our ability to attract and retain qualified employees. We face intense competition in attracting and retaining key employees, including investment, marketing, finance, legal, compliance and other professionals. If we are unable to attract and retain qualified employees, our results of operations and financial condition may be adversely impacted.

        We distribute our asset accumulation, asset management and life and specialty benefit insurance products and services through a variety of distribution channels, including our own internal sales representatives, independent brokers, banks, broker-dealers and other third-party marketing organizations. We must attract and retain sales representatives to sell our products. Strong competition exists among financial services companies for efficient sales representatives. We compete with other financial services companies for sales representatives primarily on the basis of our financial position, support services and compensation and product features. If we are unable to attract and retain sufficient sales representatives to sell our products, our ability to compete and revenues from new sales would suffer.

Our international businesses face political, legal, operational and other risks that could reduce our profitability in those businesses.

        Our international businesses are subject to comprehensive regulation and supervision from central and/or local governmental authorities in each country in which we operate. New interpretations of existing laws and regulations or the adoption of new laws and regulations may harm our international businesses and reduce our profitability in those businesses. For example, Mexican legislation requires that all employees contribute to a mandatory pension fund. When employees do not select a pension provider ("AFORE"), they are assigned to an AFORE by the Mexican regulator. Numerous AFOREs, including Principal AFORE, have been assigned such customers. The Mexican regulator re-assigns these customers based on various investment criteria. If, and to the extent, existing customers are reassigned, it would have a negative impact on our revenues and earnings.

        Our international businesses face political, legal, operational and other risks that we do not face in our operations in the U.S. We face the risk of discriminatory regulation, nationalization or expropriation of assets, price controls and exchange controls or other restrictions that prevent us from transferring funds from these operations out of the countries in which they operate or converting local currencies we hold into U.S. dollars or other currencies. Some of our international businesses are, and are likely to continue to be, in emerging or potentially volatile markets. In addition, we rely on local staff, including local sales forces, in these countries where there is a risk that we may encounter labor problems with local staff, especially in countries where workers' associations and trade unions are strong. Some of our international businesses are joint ventures in which we hold a minority interest. In these joint ventures, we lack complete management and operational control over the operations, which may limit our ability to take action to protect or increase the value of our investment in the joint venture.

We may face losses if our actual experience differs significantly from our pricing and reserving assumptions.

        Our profitability depends significantly upon the extent to which our actual experience is consistent with the assumptions used in setting prices for our products and establishing liabilities for future insurance and annuity policy benefits and claims. The premiums that we charge and the liabilities that we hold for future policy benefits are based on assumptions reflecting a number of factors, including the amount of premiums that we will receive in the future, rate of return on assets we purchase with premiums received, expected claims, mortality, morbidity, expenses and persistency, which is the measurement of the percentage of insurance policies remaining in force from year to year. However, due to the nature of the underlying risks and the high degree of uncertainty associated with the determination of the liabilities for unpaid policy benefits and claims, we cannot determine precisely the amounts we will ultimately pay to settle these liabilities. As a result, we may experience volatility in the level of our profitability and our reserves from period-to-period, particularly for our health and disability insurance products. To the extent that actual experience is less favorable than our underlying assumptions, we could be required to increase our liabilities, which may harm our financial strength and reduce our profitability.

        For example, if mortality rates are higher than our pricing assumptions, we will be required to make greater claims payments on our life insurance policies than we had projected. However, this risk may be partially offset by our payout

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annuity business, where an increase in mortality rates will result in a decrease in benefit payments, and our use of third party reinsurance. Our results of operations may also be adversely impacted by an increase in morbidity rates.

        Our results of operations may also be adversely impacted if our actual investment earnings differ from our pricing and reserve assumptions. Changes in economic conditions may lead to changes in market interest rates or changes in our investment strategies, either of which could cause our actual investment earnings to differ from our pricing and reserve assumptions.

        For additional information on our insurance reserves, see Item 7. "Management's Discussion and Analysis of Financial Condition and Results of Operations — Critical Accounting Policies and Estimates — Insurance Reserves."

Our ability to pay stockholder dividends and meet our obligations may be constrained by the limitations on dividends Iowa insurance laws impose on Principal Life.

        We are an insurance holding company whose assets include all of the outstanding shares of the common stock of Principal Life and other subsidiaries. Our ability to pay dividends to our stockholders and meet our obligations, including paying operating expenses and any debt service, depends upon the receipt of dividends from Principal Life. Iowa insurance laws impose limitations on the ability of Principal Life to pay dividends to us. Any inability of Principal Life to pay dividends to us in the future may cause us to be unable to pay dividends to our stockholders and meet our other obligations. See Item 7. "Management's Discussion and Analysis of Financial Condition and Results of Operations — Liquidity and Capital Resources" for a discussion of regulatory restrictions on Principal Life's ability to pay us dividends.

The pattern of amortizing our DPAC and other actuarial balances on our universal life-type insurance contracts, participating life insurance policies and certain investment contracts may change, impacting both the level of the DPAC and other actuarial balances and the timing of our net income.

        Amortization of the DPAC asset and other actuarial balances depends on the actual and expected profits generated by the lines of business that incurred the expenses. Expected profits are dependent on assumptions regarding a number of factors including investment returns, benefit payments, expenses, mortality and policy lapse. Due to the uncertainty associated with establishing these assumptions, we cannot, with precision, determine the exact pattern of profit emergence. As a result, amortization of these balances will vary from period-to-period. To the extent that actual experience emerges less favorably than expected, or our expectation for future profits decreases, the DPAC asset and other actuarial balances may be adjusted, reducing our profitability in the current period.

        For additional information, see Item 7. "Management's Discussion and Analysis of Financial Condition and Results of Operation — Critical Accounting Policies and Estimates — Deferred Policy Acquisition Costs and Other Actuarial Balances."

We may need to fund deficiencies in our Closed Block assets.

        In connection with its conversion in 1998 into a stock life insurance company, Principal Life established an accounting mechanism, known as a "Closed Block" for the benefit of participating ordinary life insurance policies that had a dividend scale in force on July 1, 1998. Dividend scales are the actuarial formulas used by life insurance companies to determine amounts payable as dividends on participating policies based on experience factors relating to, among other things, investment results, mortality, lapse rates, expenses, premium taxes and policy loan interest and utilization rates. The Closed Block was designed to provide reasonable assurance to policyholders included in the Closed Block that, after the conversion, assets would be available to maintain the aggregate dividend scales in effect for 1997 if the experience underlying such scales were to continue.

        We allocated assets to the Closed Block as of July 1, 1998, in an amount such that we expected their cash flows, together with anticipated revenues from the policies in the Closed Block, to be sufficient to support the Closed Block business, including payment of claims, certain direct expenses, charges and taxes and to provide for the continuation of aggregate dividend scales in accordance with the 1997 policy dividend scales if the experience underlying such scales continued, and to allow for appropriate adjustments in such scales if the experience changed. We bear the costs of administrative expenses associated with Closed Block policies and, accordingly, these costs were not funded as part of the assets allocated to the Closed Block. Any increase in such costs in the future will be borne by us. As of December 31, 2012, Closed Block assets and liabilities were $ 4,456.7 million and $ 5,118.1 million, respectively.

        We will continue to pay guaranteed benefits under the policies included in the Closed Block, in accordance with their terms. The Closed Block assets, cash flows generated by the Closed Block assets and anticipated revenues from policies included in the Closed Block may not be sufficient to provide for the benefits guaranteed under these policies. If they are not sufficient, we must fund the shortfall. Even if they are sufficient, we may choose for business reasons to support dividend payments on policies in the Closed Block with our general account funds.

        The Closed Block assets, cash flows generated by the Closed Block assets and anticipated revenues from policies in the Closed Block will benefit only the holders of those policies. In addition, to the extent that these amounts are greater than the amounts estimated at the time we funded the Closed Block, dividends payable in respect of the policies included in the Closed Block may be greater than they would have been in the absence of a Closed Block. Any excess net income will be available for distribution over time to Closed Block policyholders but will not be available to our stockholders.

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A pandemic, terrorist attack or other catastrophic event could adversely affect our net income.

        Our mortality and morbidity experience could be adversely impacted by a catastrophic event. In addition, a severe catastrophic event may cause significant volatility in global financial markets, disruptions to commerce and reduced economic activity. The resulting macroeconomic conditions could adversely affect our cash flows, as well as the value and liquidity of our invested assets. We may also experience operational disruptions if our employees are unable or unwilling to come to work due to a pandemic or other catastrophe. We have developed extensive contingency plans to minimize the risk of operational disruptions. In addition, our use of reinsurance reduces our exposure to adverse mortality experience. Despite these measures, we may still be exposed to losses in the event of a pandemic, terrorist attack or other catastrophe.

Our reinsurers could default on their obligations or increase their rates, which could adversely impact our net income and profitability.

        We cede life and health insurance to other insurance companies through reinsurance. See Item 8. "Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 1, Nature of Operations and Significant Accounting Policies." However, we remain liable to the policyholder, even if the reinsurer defaults on its obligations with respect to the ceded business. If a reinsurer fails to meet its obligations, we will be forced to cover the claims on the reinsured policies. In addition, a reinsurer's insolvency may cause us to lose our reserve credits on the ceded business, in which case we would be required to establish additional reserves.

        The premium rates that we charge are based, in part, on the assumption that reinsurance will be available at a certain cost. Some of our reinsurance contracts contain provisions which limit the reinsurer's ability to increase rates on in-force business; however, some do not. If a reinsurer raises the rates that it charges on a block of in-force business, our profitability may be negatively impacted if we are not able to pass the increased costs on to the customer. If reinsurers raise the rates that they charge on new business, we may be forced to raise the premiums that we charge, which could have a negative impact on our competitive position.

        To mitigate the risks associated with the use of reinsurance, we carefully select our reinsurers, and we monitor their ratings and financial condition on a regular basis. We also spread our business among several reinsurers, in order to diversify our risk exposure.

We face risks arising from acquisitions of businesses.

        We have engaged in acquisitions of businesses in the past, and expect to continue to do so in the future. We face a number of risks arising from acquisition transactions, including difficulties in integrating the acquired business into our operations, difficulties in assimilating and retaining employees and intermediaries, difficulties in retaining the existing customers of the acquired entity, unforeseen liabilities that arise in connection with the acquired business and unfavorable market conditions that could negatively impact our growth expectations for the acquired business. These risks may prevent us from realizing the expected benefits from acquisitions and could result in the impairment of goodwill and/or intangible assets recognized at the time of acquisition.

        For additional information on our goodwill and other intangible assets, see Item 7. "Management's Discussion and Analysis of Financial Condition and Results of Operations — Critical Accounting Policies and Estimates — Goodwill and Other Intangible Assets."

We face risks arising from the acquisition of Cuprum

Our increased debt obligations as a result of the acquisition could have negative consequences.

        Our increased debt obligations could have negative consequences, including:

•

Making us more vulnerable to general adverse economic and industry conditions;



•

Requiring us to dedicate increased cash flow from operations to the payment of principal and interest on our debt, thereby reducing the funds we have available for other purposes;



•

Reducing our ability to execute on our strategy and reducing our flexibility in planning for or reacting to changes in our business and market conditions and



•

Limiting our access to capital markets such that additional capital may not be available or may only be available on unfavorable terms.

We may not realize the expected benefits of the Cuprum acquisition.

        The success of the Cuprum acquisition will in part depend on our ability to successfully on-board and operate Cuprum in conjunction with our existing businesses and to manage the future growth of Cuprum. The process of assuming control of Cuprum may be complex, costly and time-consuming and could include the following potential difficulties among others:

•

Implementing our business plan for our complementary businesses;

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•

Unanticipated issues in integrating logistics, information, communications and other systems;



•

Retaining key employees of Cuprum;



•

Changes in applicable laws and regulations or conditions imposed by regulators;



•

Operating risks inherent in Cuprum's business;



•

Retaining and growing Cuprum's customers and



•

Realizing revenue and expense synergies.

        In addition, we expect to continue to incur significant costs in connection with the Cuprum acquisition and the related operation of the Cuprum business. The Cuprum acquisition may also divert our or Cuprum's management's attention from other business concerns, which could have a negative effect on either our or Cuprum's business, results of operations or financial condition.

The obligations and liabilities of Cuprum, some of which may be unanticipated or unknown, may be greater than we have anticipated, which may diminish the value of Cuprum to us.

        Cuprum's obligations and liabilities, some of which may not have been disclosed to us or may not be reflected or reserved for in Cuprum's historical financial statements, may be greater than we have anticipated. The obligations and liabilities of Cuprum could have a material adverse effect on Cuprum's business or Cuprum's value to us or to our business, financial condition or results of operations. We have only limited indemnification from the Sellers under the Sales and Purchase Promise Agreement with respect to obligations or liabilities of Cuprum, whether known or unknown.

The acquisition of Cuprum increases our exposure in Chile and our overall exposure to international operations.

        The growth and profitability of Cuprum depend on the level of economic activity in Chile. The Chilean economy is influenced, to varying degrees, by economic conditions in other emerging market countries, including China. Economic conditions in Chile and other emerging market countries could have an adverse effect on Cuprum's and our business, results of operations or financial condition. In addition, the acquisition of Cuprum will increase our overall exposure to risks related to international operations. See "— Our international businesses face political, legal, operational and other risks that could reduce our profitability in those businesses."

        There can be no assurance that the Chilean economy will continue to grow in the future or that future developments in or affecting the Chilean economy will not have a material adverse effect on Cuprum's business, results of operations or financial condition; nor can there be assurance that future developments in or affecting the Chilean economy will not impair our ability to proceed with our business plan or have a material adverse effect on us. Cuprum is also subject to comprehensive regulation and supervision from governmental authorities in Chile. New interpretations of existing laws and regulations or the adoption of new laws and regulations may harm Cuprum's business and reduce its profitability.

        The Cuprum acquisition will increase our exposure to fluctuations in Chilean currency exchange rates, which affects the translation of local operating results into our consolidated financial statements and could reduce our profitability. See "— Fluctuations in foreign currency exchange rates could reduce our profitability."

Changes in laws, regulations or accounting standards may reduce our profitability.

Changes in regulations may reduce our profitability.

        Our insurance business is subject to comprehensive state regulation and supervision throughout the U.S. and in the international markets in which we operate. We are also impacted by federal legislation and administrative policies in areas such as employee benefit plan regulation, financial services regulations and federal taxation. The primary purpose of state regulation of the insurance business is to protect policyholders, not stockholders. The laws of the various states establish insurance departments with broad powers to regulate such matters as:

•

licensing companies to transact business,



•

licensing agents,



•

admitting statutory assets,



•

mandating a number of insurance benefits,



•

regulating premium rates,



•

approving policy forms,



•

regulating unfair trade and claims practices,



•

establishing statutory reserve requirements and solvency standards,



•

fixing maximum interest rates on life insurance policy loans and minimum rates for accumulation of surrender values,

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•

restricting various transactions between affiliates and



•

regulating the types, amounts and valuation of investments.

        State insurance regulators, federal regulators and the NAIC continually reexamine existing laws and regulations, and may impose changes in the future.

        State insurance guaranty associations have the right to assess insurance companies doing business in their state for funds to help pay the obligations of insolvent insurance companies to policyholders and claimants. Because the amount and timing of an assessment is beyond our control, the liabilities we have established for these potential assessments may not be adequate. In addition, regulators may change their interpretation or application of existing laws and regulations. Changes in laws or regulations or the interpretation thereof could significantly increase our compliance costs and adversely affect our profitability and financial strength.

        Federal legislation and administrative policies in areas such as employee benefit plan regulation, financial services regulation and federal taxation can reduce our profitability. For example, the U.S. Congress has, from time to time, considered legislation relating to changes in the Employee Retirement Income Security Act of 1974 to permit application of state law remedies, such as consequential and punitive damages, in lawsuits for wrongful denial of benefits, which, if adopted, could increase our liability for damages in future litigation. Additionally, new interpretations of existing laws and the passage of new legislation may harm our ability to sell new policies and increase our claims exposure on policies we issued previously. In addition, reductions in contribution levels to defined contribution plans may decrease our profitability.

Changes in tax laws could increase our tax costs and reduce sales of our insurance, annuity and investment products.

        Current federal income tax laws generally permit the tax-deferred accumulation of earnings on the premiums paid by the holders of annuities and life insurance products. Taxes, if any, are payable on income attributable to a distribution under the contract for the year in which the distribution is made. The U.S. Congress has, from time to time, considered legislation that would reduce or eliminate the benefit of such deferral of taxation on the accretion of value within life insurance and nonqualified annuity contracts. Enactment of this legislation, including a simplified "flat tax" income structure with an exemption from taxation for investment income, could result in fewer sales of our insurance, annuity and investment products. In addition, changes in the federal estate tax laws could negatively affect the demand for the types of life insurance used in estate planning.

        In addition, we benefit from certain tax items, including but not limited to, tax-exempt bond interest, dividends-received deductions, tax credits (such as foreign tax credits) and insurance reserve deductions. From time to time, the U.S. Congress, as well as foreign, state and local governments, considers legislation that could reduce or eliminate the benefits associated with these tax items. If such legislation is adopted, our profitability could be negatively impacted. We continue to evaluate the impact that potential tax reform, which lacks sufficient detail and is relatively uncertain, may have on our future results of operations and financial condition.

Changes in federal, state and foreign securities laws may reduce our profitability.

        Our asset management and accumulation and life insurance businesses are subject to various levels of regulation under federal, state and foreign securities laws. These laws and regulations are primarily intended to protect investors in the securities markets or investment advisory or brokerage clients and generally grant supervisory agencies broad administrative powers, including the power to limit or restrict the conduct of business for failure to comply with such laws and regulations. The downturn in the financial markets and resulting market-wide losses have caused legislative and regulatory bodies to consider various changes to existing securities laws and the legal framework governing the financial industry. Changes to these laws or regulations — or the interpretation thereof — that restrict the conduct of our business could significantly increase our compliance costs and reduce our profitability.

Financial services regulatory reform may reduce our profitability, impact how we do business or limit our ability to engage in certain capital expenditures.

        On July 21, 2010, the Dodd-Frank Act became law. The Dodd-Frank Act makes extensive changes to the laws regulating financial services firms and requires various federal agencies to adopt a broad range of new implementation rules and regulations. The federal agencies were given significant discretion in drafting the implementation rules and regulations, and consequently, many of the details and much of the impact of the Dodd-Frank Act will not be known for many months or years. In addition, the legislation mandates multiple studies and reports for Congress, which could result in additional legislative or regulatory action.

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        In July 2011, we became subject to oversight from and examination by the Federal Reserve and, therefore, various banking, capital and liquidity requirements may apply to us, due to our wholly owned full-service banking subsidiary. Due to our ownership of our federal savings bank subsidiary, we are classified under federal banking law as a SLHC. The Federal Reserve has adopted a procedure for deregistration as a SLHC for companies seeking to avail themselves of an exemption included with the Dodd-Frank Act. We intend to submit an application to the Federal Reserve to deregister as a SLHC. For our application to be successful, our federal savings bank will need to agree to limit its activities to only those permitted for a limited purpose trust institution. Deregistration from SLHC status will exempt us from capital requirements the Federal Reserve promulgates for SLHCs. There can be no assurance our application will be successful. We anticipate this process will take approximately one year.

        Nonetheless, even if we are successful in deregistering as a SLHC, it is possible (although we currently believe unlikely) that we could be designated as a "Nonbank Systemically Important Financial Institution" by the Financial Stability Oversight Council ("FSOC"). Being so designated would subject us to enhanced oversight and prudential standards by the Federal Reserve, beyond those applicable to our competitors not so designated.

        As to derivative activities, while the initial regulations indicate that we will not fall within the definition of a "Major Swap Participant" ("MSP"), it is possible that changes in the final rules could alter this interpretation. Designation as an MSP will result in more oversight of derivative transactions under the separate jurisdictions of the SEC and the Commodities Futures Trading Commission. This includes swaps traded through either regulated exchanges or approved clearinghouses, and requires additional collateral to support derivatives transactions.

        The changes resulting from the Dodd-Frank Act and the yet to be finalized implementation rules and regulations, as well as discretionary actions by the Federal Reserve and FSOC, may increase our compliance costs, lower the profitability of our business activities, require changes to certain of our business practices or otherwise adversely affect our business.

Changes in accounting standards may negatively impact our reported profitability and financial ratios.

        Accounting standards are subject to change and can negatively impact our reported profitability. See Item 8. "Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 1, Nature of Operations and Significant Accounting Policies." In addition to recently issued accounting guidance, the U.S. and international standard setters have a full agenda of topics they plan to review, any of which have the potential to negatively impact our reported profitability and financial ratios. The results for past accounting periods are not necessarily indicative of the results to be expected for any future accounting period.

We may be unable to mitigate the impact of Regulation XXX and Actuarial Guideline 38, potentially resulting in a negative impact to our capital position and/or a reduction in sales of term and universal life insurance products.

        The NAIC Model Regulation entitled "Valuation of Life Insurance Policies," commonly known as "Regulation XXX", establishes statutory reserve requirements for term life insurance policies and universal life insurance policies with secondary guarantees. Actuarial Guideline 38 ("AG38") clarifies the application of Regulation XXX with respect to certain universal life insurance products with secondary guarantees.

        The NAIC has amended AG38 in an effort to create more clarity around reserving practices for certain policies that are accounted for under this guideline. The effects of the changes to AG38 are two-fold:

•

Reserves for certain inforce policies will be subject to additional statutory reserve minimums effective for the December 31, 2012, reporting period and



•

Reserves for businesses sold after January 1, 2013, will be subject to a higher statutory reserve basis.

        We have implemented reinsurance and capital management actions to mitigate the capital impact of Regulation XXX and AG38 on our term and universal life insurance business. We cannot provide assurance that we will be able to continue to implement these actions for reinsuring future increases in redundant term and universal life insurance reserves. If we are unable to mitigate the impact of Regulation XXX and AG38 on these products, additional capital will be required to support those products, and we may be required to increase prices and/or reduce sales of our term and universal life insurance products. Even if we are able to continue utilizing these mitigating actions of reinsurance and related activity, our results could be negatively impacted due to costs related to additional amounts of reinsurance needed.

A computer system failure or security breach could disrupt our business, damage our reputation and adversely impact our profitability.

        We rely on computer systems to conduct business, including customer service, marketing and sales activities, customer relationship management and producing financial statements. While we have policies, procedures, automation and backup plans designed to prevent or limit the effect of failure, our computer systems may be vulnerable to disruptions or breaches as the result of natural disasters, man-made disasters, criminal activity, pandemics, or other events beyond our control. The failure of our computer systems for any reason could disrupt our operations, result in the loss of customer business and adversely impact our profitability.

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        We retain confidential information on our computer systems, including customer information and proprietary business information. Any compromise of the security of our computer systems that results in the disclosure of personally identifiable customer information could damage our reputation, expose us to litigation, increase regulatory scrutiny and require us to incur significant technical, legal and other expenses.

Loss of key vendor relationships or failure of a vendor to protect information of our customers or employees could adversely affect our business or result in losses.

        We rely on services and products provided by many vendors in the United States and abroad. These include, for example, vendors of computer hardware and software and vendors of services. In the event that one or more of our vendors suffers a bankruptcy or otherwise becomes unable to continue to provide products or services, or fails to protect personal information of our customers or employees, we may suffer operational impairments, reputational damage and financial losses.

Results of litigation and regulatory investigations may affect our financial strength or reduce our profitability.

        We are regularly involved in litigation, both as a defendant and as a plaintiff, but primarily as a defendant. Litigation naming us as a defendant ordinarily arises out of our business operations as a provider of asset management and accumulation products and services; life, health and disability insurance; and our investment activities.

        We are, from time to time, also involved in various governmental, regulatory and administrative proceedings and inquiries. We have received regulatory inquiries from certain state insurance regulators and other officials relating to compliance with unclaimed property laws and the use of data available on the U.S. Social Security Administration's Death Master File (or a similar database) to identify instances where benefits under life insurance policies, annuities and retained asset accounts are payable. It is possible that other jurisdictions may pursue similar inquiries and that such inquiries may result in payments to beneficiaries, escheatment of funds deemed abandoned under state laws and changes to procedures for the identification and escheatment of abandoned property.

        These factors may affect our financial strength or reduce our profitability. For further discussion on litigation and regulatory investigation risk, see Item 3. "Legal Proceedings," Item 8. "Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 12, Contingencies, Guarantees and Indemnifications" under the caption, "Litigation and Regulatory Contingencies" and Item 8. "Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 10, Income Taxes."

From time to time we may become subject to tax audits, tax litigation or similar proceedings, and as a result we may owe additional taxes, interest and penalties in amounts that may be material.

        We are subject to income taxes in the United States as well as many other jurisdictions. In determining our provisions for income taxes and our accounting for tax-related matters in general, we are required to exercise judgment. We regularly make estimates where the ultimate tax determination is uncertain. The final determination of any tax audit, appeal of the decision of a taxing authority, tax litigation or similar proceedings may be materially different from that reflected in our historical financial statements. The assessment of additional taxes, interest and penalties could be materially adverse to our current and future results of operations and financial condition.

Fluctuations in foreign currency exchange rates could reduce our profitability.

        Principal International generally writes policies denominated in various local currencies and invests the premiums and deposits in local currencies. Although investing in local currencies limits the effect of currency exchange rate fluctuation on local operating results, fluctuations in such rates affect the translation of these results into our consolidated financial statements. For further discussion on foreign currency exchange risk, see Item 7A. "Quantitative and Qualitative Disclosures About Market Risk — Foreign Currency Risk."

Applicable laws and our certificate of incorporation and by-laws may discourage takeovers and business combinations that some stockholders might consider in their best interests.

        State laws and our certificate of incorporation and by-laws may delay, defer, prevent, or render more difficult a takeover attempt that some stockholders might consider in their best interests. For instance, they may prevent our stockholders from receiving the benefit from any premium to the market price of our common stock offered by a bidder in a takeover context. Even in the absence of a takeover attempt, the existence of these provisions may adversely affect the prevailing market price of our common stock if they are viewed as discouraging takeover attempts in the future.

        State laws and our certificate of incorporation and by-laws may also make it difficult for stockholders to replace or remove our management. These provisions may facilitate management entrenchment, which may delay, defer or prevent a change in our control, which may not be in the best interests of our stockholders.

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        The following provisions, included in our certificate of incorporation and by-laws, may also have anti-takeover effects and may delay, defer or prevent a takeover attempt that some stockholders might consider in their best interests. In particular, our certificate of incorporation and by-laws:

•

permit our Board of Directors to issue one or more series of preferred stock;



•

divide our Board of Directors into three classes;



•

limit the ability of stockholders to remove directors;



•

prohibit stockholders from filling vacancies on our Board of Directors;



•

prohibit stockholders from calling special meetings of stockholders;



•

impose advance notice requirements for stockholder proposals and nominations of directors to be considered at stockholder meetings and



•

require the approval of at least 75% of the voting power our outstanding common stock for the amendment of our by-laws and provisions of our certificate of incorporation governing:



•

the classified board,



•

the director's discretion in determining what he or she reasonably believes to be in the best interests of Principal Financial Group, Inc.,



•

the liability of directors,



•

the removal of directors by shareholders,



•

the prohibition on stockholder actions by written consent and



•

the supermajority voting requirements.

        In addition, Section 203 of the General Corporation Law of the State of Delaware may limit the ability of an "interested stockholder" to engage in business combinations with us. An interested stockholder is defined to include persons owning 15% or more of our outstanding voting stock.

Our financial results may be adversely impacted by global climate changes.

        Atmospheric concentrations of carbon dioxide and other greenhouse gases have increased dramatically since the industrial revolution, resulting in a gradual increase in global average temperatures and an increase in the frequency and severity of natural disasters. These trends are expected to continue in the future and have the potential to impact nearly all sectors of the economy to varying degrees. Our initial research indicates that climate change does not pose an imminent or significant threat to our operations or business, but we will continue to monitor new developments in the future.

        Potential impacts may include the following:

•

Changes in temperatures and air quality may adversely impact our mortality and morbidity rates. For example, increases in the level of pollution and airborne allergens may cause an increase in upper respiratory and cardiovascular diseases, leading to increased claims in our insurance businesses. However, the risk of increased mortality on our life insurance business may be partly offset by our payout annuity business, where an increase in mortality results in a decrease in benefit payments.



•

Climate change may impact asset prices, as well as general economic conditions. For example, rising sea levels may lead to decreases in real estate values in coastal areas. Additionally, government policies to slow climate change (e.g., setting limits on carbon emissions) may have an adverse impact on sectors such as utilities, transportation and manufacturing. Changes in asset prices may impact the value of our fixed income, real estate and commercial mortgage investments. We manage our investment risks by maintaining a well-diversified portfolio, both geographically and by sector. We also monitor our investments on an ongoing basis, allowing us to adjust our exposure to sectors and/or geographical areas that face severe risks due to climate change.



•

A natural disaster that affects one of our office locations could disrupt our operations and pose a threat to the safety of our employees. However, we have extensive Business Continuity and Disaster Recovery planning programs in place to help mitigate this risk.

Item 1B.    Unresolved Staff Comments

        None.

Item 2.    Properties

        As of December 31, 2012, we own 27 properties in our home office complex in Des Moines, Iowa, and in various other locations. Of these 27 properties, 12 are office buildings, 1 is a warehouse facility, 11 are parking lots and ramps,

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1 is a park/green space, 1 is a childcare center and 1 is a power generation plant. Of the office and warehouse space, we occupy approximately 93% of the 3.0 million square feet of space in these buildings. The balance of the space in these buildings is rented to commercial tenants or is occupied by the property management company servicing these properties. We lease office space for various offices located throughout the U.S. and internationally. We believe that our owned and leased properties are suitable and adequate for our current business operations.

Item 3.    Legal Proceedings

        Disclosure concerning material legal proceedings can be found in Item 8. "Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 12, Contingencies, Guarantees and Indemnifications" under the caption, "Litigation and Regulatory Contingencies" and Item 8. "Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 10, Income Taxes" under the caption, "Other Tax Information," which are incorporated here by this reference.

Executive Officers of the Registrant

        The following information is furnished with respect to our executive officers, each of whom is elected by and serves at the pleasure of the Board of Directors.

        Timothy M. Dunbar, 55, has been Senior Vice President of the Company and Principal Life since 2011, and Chief Investment Officer of the Company and Principal Life since January 1, 2013. Prior to that date, Mr. Dunbar was in charge of Strategy and Finance for the Company and Principal Life in 2011 and 2012, overseeing the business management and strategic direction of the capital markets, corporate strategy and corporate treasury areas. He retains his responsibility for capital markets. Mr. Dunbar previously served as the executive director and head of equities for Principal Global Investors from 2004 until 2011.

        Gregory B. Elming, 52, has been Senior Vice President and Chief Risk Officer of the Company and Principal Life since March 2011. Prior to that time, he was Senior Vice President and Controller of the Company and Principal Life since 2007 and Vice President and Controller of the Company and Principal Life since 2002.

        Daniel J. Houston, 51, who heads the Retirement and Investor Services and U.S. Insurance Solutions segments of our operations, was named President, Retirement, Insurance and Financial Services of the Company and Principal Life on January 1, 2010. He was President, Retirement and Investor Services of the Company and Principal Life from February 2008 until January 2010, and was Executive Vice President, Retirement and Investor Services of the Company and Principal Life from June 2006 to February 2008.

        Terrance J. Lillis, 60, has been Senior Vice President and Chief Financial Officer of the Company and Principal Life since August 2008 and Senior Vice President of the Company and Principal Life since May 2008. Prior to that time, he was Chief Financial Officer — Retirement and Investor Services division of Principal Life since December 2001.

        James P. McCaughan, 59, who heads the Principal Global Investors segment of our operations, has been President, Principal Global Investors of the Company and Principal Life since December 2003. Prior to that time, he served as Executive Vice President and global head of asset management for the Company and Principal Life since April 2002. From 2000 to 2002, he was Chief Executive Officer of the Americas division of Credit Suisse Asset Management in New York, New York.

        Mary A. O'Keefe, 56, who heads Corporate Relations, has been Senior Vice President and Chief Marketing Officer of the Company and Principal Life since February 2005, Senior Vice President of the Company since April 2001, and Senior Vice President of Principal Life since January 1998.

        Gary P. Scholten, 55, has been Senior Vice President and Chief Information Officer of the Company and Principal Life since November 2002. From 1998 to 2002, he was Vice President of retail information services of Principal Life.

        Karen E. Shaff, 58, has been Executive Vice President and General Counsel of the Company and Principal Life since February 2004. Prior thereto, she was Senior Vice President and General Counsel of the Company since April 2001, and Senior Vice President and General Counsel of Principal Life since January 2000.

        Luis Valdes, 55, who has been the head of the Principal International segment of our operations since March 2012, has been President, Principal International of the Company and Principal Life since March 2011. Prior to his current position, he has been Senior Vice President and President — PFG Latin America of the Company and Principal Life since March 2010, and was Vice President — Principal International of Principal Life from 2000 until March 2010.

        Larry D. Zimpleman, 61, has been a Director of the Company and Principal Life since 2006. He has been Chairman, President and Chief Executive Officer of the Company and Principal Life since May 2009 and was President and Chief Executive Officer of the Company and Principal Life from May 2008 to May 2009. Prior thereto, he was President and Chief Operating Officer of the Company and Principal Life from 2006 to May 2008. He was President, Retirement and Investor Services of the Company and Principal Life from December 2003 through May 2006. Mr. Zimpleman served as chairman of the board and a director of the Principal Funds from December 2001 to December 2008.

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PART II

Item 5.    Market for Registrant's Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities

        Our common stock began trading on the New York Stock Exchange ("NYSE") under the symbol "PFG" on October 23, 2001. Prior to such date, there was no established public trading market for our common stock. On February 6, 2013, there were 384,486 stockholders of record of our common stock.

        The following table presents the high and low prices for our common stock on the NYSE for the periods indicated and the dividends declared per share during such periods.

        We changed to paying dividends quarterly on our common stock in 2012. Previously, we paid our common stock dividends annually. Future dividend decisions will be based on and affected by a number of factors, including our results and financial requirements and the impact of regulatory restrictions. See Item 7. "Management's Discussion and Analysis of Financial Condition and Results of Operations — Liquidity and Capital Resources" for a discussion of regulatory restrictions on Principal Life's ability to pay dividends.

        The following table presents the amount of our share purchase activity for the periods indicated:

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Item 6.   Selected Financial Data

        The following table sets forth certain selected historical consolidated financial information. We derived the consolidated financial information (except for amounts referred to as "Other Supplemental Data") for each of the years ended December 31, 2012, 2011 and 2010 and as of December 31, 2012 and 2011 from our audited consolidated financial statements and notes to the financial statements included in this Form 10-K. We derived the consolidated financial information (except for amounts referred to as "Other Supplemental Data") for the years ended December 31, 2009 and 2008 and as of December 31, 2010, 2009 and 2008 from our audited consolidated financial statements not included in this Form 10-K. The following summary of consolidated financial information (except for amounts referred to as "Other Supplemental Data") has been prepared in accordance with U.S. GAAP.

        In order to fully understand our consolidated financial information, please also see Item 7. "Management's Discussion and Analysis of Financial Condition and Results of Operations" and our audited consolidated financial statements and the notes to the financial statements included in this Form 10-K. The results for past accounting periods are not necessarily indicative of the results to be expected for any future accounting period.

Item 7.   Management's Discussion and Analysis of Financial Condition and Results of Operations

        The following analysis discusses our financial condition as of December 31, 2012, compared with December 31, 2011, and our consolidated results of operations for the years ended December 31, 2012, 2011 and 2010, and, where appropriate, factors that may affect our future financial performance. The discussion should be read in conjunction with our audited consolidated financial statements and the related notes to the financial statements and the other financial information included elsewhere in this Form 10-K.

Forward-Looking Information

        Our narrative analysis below contains forward-looking statements intended to enhance the reader's ability to assess our future financial performance. Forward-looking statements include, but are not limited to, statements that represent our beliefs concerning future operations, strategies, financial results or other developments, and contain words and phrases such as "anticipate," "believe," "plan," "estimate," "expect," "intend," and similar expressions. Forward-looking

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statements are made based upon management's current expectations and beliefs concerning future developments and their potential effects on us. Such forward-looking statements are not guarantees of future performance.

        Actual results may differ materially from those included in the forward-looking statements as a result of risks and uncertainties. Those risks and uncertainties include, but are not limited to the risk factors listed in Item 1A. "Risk Factors."

Overview

        We provide financial products and services through the following reportable segments:

•

Retirement and Investor Services is organized into the Accumulation business, which includes full service accumulation, Principal Funds (our mutual fund business), individual annuities and bank and trust services; and the Guaranteed business, which includes investment only and full service payout. We offer a comprehensive portfolio of asset accumulation products and services for retirement savings and investment:



•

To businesses of all sizes with a concentration on small and medium-sized businesses, we offer products and services for defined contribution pension plans, including 401(k) and 403(b) plans, defined benefit pension plans, nonqualified executive benefit plans and ESOP consulting services. For more basic investment needs, we offer SIMPLE IRA and payroll deduction plans;



•

To large institutional clients, we also offer investment-only products, including GICs and funding agreements and



•

To employees of businesses and other individuals, we offer the ability to accumulate savings for retirement and other purposes through mutual funds, individual annuities and bank products.



•

Principal Global Investors, which consists of our asset management operations, manages assets for sophisticated investors around the world, using a multi-boutique strategy that enables the segment to provide an expanded range of diverse investment capabilities including equity, fixed income and real estate investments. Principal Global Investors also has experience in currency management, asset allocation, stable value management and other structured investment strategies.



•

Principal International, which offers retirement products and services, annuities, mutual funds, institutional asset management and life insurance accumulation products through operations in Brazil, Chile, China, Hong Kong SAR, India, Mexico and Southeast Asia.



•

U.S. Insurance Solutions, which provides individual life insurance as well as specialty benefits in the U.S. Our individual life insurance products include universal and variable universal life insurance and traditional life insurance. Our specialty benefit products include group dental and vision insurance, individual and group disability insurance and group life insurance. Effective January 1, 2011, wellness services and fee-for-service claims administration transitioned to the Specialty Benefits division from the Corporate segment.



•

Corporate, which manages the assets representing capital that has not been allocated to any other segment. Financial results of the Corporate segment primarily reflect our financing activities (including interest expense and preferred stock dividends), income on capital not allocated to other segments, inter-segment eliminations, income tax risks and certain income, expenses and other after-tax adjustments not allocated to the segments based on the nature of such items.

Economic Factors and Trends

        In 2012, positive net customer cash flows and market performance led to increases in our Retirement and Investor Services segment's account values and our Principal Global Investors segment's AUM. Since account values and AUM are the base by which these businesses generate revenues, the increase in account values and AUM has contributed to the overall improvement of our profits.

        In our Principal International segment, we continued to grow our business organically through our existing subsidiaries and joint ventures and through strategic acquisitions. Local currency AUM, a key indicator of earnings growth for the segment, increased significantly as a result of positive net customer cash flows and market performance. The financial results for the Principal International segment are also impacted by fluctuations of the foreign currency to U.S. dollar exchange rates for the countries in which we have business.

        The U.S. Insurance Solutions segment has been impacted by lower interest rates for the past few years as well as decreases in our long term interest rate assumptions. The current low interest rate environment has caused spread compression, whereas the decrease in long term interest rate assumptions has led to higher reserves and lower profit margins in both divisions. In addition, we experienced a slowdown in the growth of group products between 2009 and 2010 relative to prior years due to a combination of lower sales, higher lapses, reduced growth in salaries and reductions in covered lives of our existing group customers as a result of economic pressure. Since 2011, we have seen signs of recovery through higher sales, slight inforce membership growth and improved retention.

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Profitability

        Our profitability depends in large part upon our:

•

amount of AUM;



•

spreads we earn that result from the difference between what we earn and what we credit to policyholders;



•

ability to generate fee revenues by providing administrative and investment management services;



•

ability to price our insurance products at a level that enables us to earn a margin over the cost of providing benefits and the related expenses;



•

ability to manage our investment portfolio to maximize investment returns and minimize risks such as interest rate changes or defaults or impairments of invested assets;



•

ability to effectively hedge fluctuations in foreign currency to U.S. dollar exchange rates on certain transactions and



•

ability to manage our operating expenses.

Critical Accounting Policies and Estimates

        The increasing complexity of the business environment and applicable authoritative accounting guidance requires us to closely monitor our accounting policies. Our significant accounting policies are described in Item 8. "Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 1, Nature of Operations and Significant Accounting Policies." We have identified critical accounting policies that are complex and require significant judgment and estimates about matters that are inherently uncertain. A summary of our critical accounting policies is intended to enhance the reader's ability to assess our financial condition and results of operations and the potential volatility due to changes in estimates and changes in guidance. The identification, selection and disclosure of critical accounting estimates and policies have been discussed with the Audit Committee of the Board of Directors.

Valuation and Impairment of Fixed Income Investments

        Fixed Maturities.    Fixed maturities include bonds, redeemable preferred stock and certain non-redeemable preferred stock. We classify our fixed maturities as either available-for-sale or trading and, accordingly, carry them at fair value in the consolidated statements of financial position. The fair values of our public fixed maturities are primarily based on market prices from independent pricing services. We have regular interactions with these vendors to ensure we understand their pricing methodologies and to confirm they are utilizing observable market information. In addition, 22% of our invested asset portfolio is invested in fixed maturities that are private placement assets, where there are no readily available market quotes to determine the fair market value. The majority of these assets are valued using a spread pricing matrix that utilizes observable market inputs. Securities are grouped into pricing categories that vary by asset class, sector, rating and average life. Each pricing category is assigned a risk spread based on studies of observable public market data or market clearing data from the investment professionals assigned to specific security classes. The expected cash flows of the security are then discounted back at the current Treasury curve plus the appropriate risk spread. Certain market events that could impact the valuation of securities include issuer credit ratings, business climate, management changes, litigation and government actions among others. See item 8. "Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 14, Fair Value Measurements" for further discussion.

        If we are unable to price a fixed maturity security from third party pricing vendors we may obtain a broker quote or utilize an internal pricing model specific to the asset utilizing relevant market information to the extent available. Less than 1% of our fixed maturities were valued using internal models.

        A rate increase based on the combined movement of interest rates and credit spreads of 100 basis points would produce a total value of approximately $41.8 billion, as compared to the recorded amount of $43.9 billion related to our fixed maturity, available-for-sale assets held by the Principal Life general account as of December 31, 2012.

        We had a $1,529.6 million increase in net unrealized gains within the U.S. fixed maturities, available-for-sale portfolio for the year ended December 31, 2012, of which an approximate $0.2 billion net unrealized gain can be attributed to an approximate 7 basis points decrease in interest rates in addition to other market factors that increased unrealized gains. We had a $741.5 million increase in net unrealized gains for the year ended December 31, 2011, of which an approximate $2.2 billion net unrealized gain can be attributed to an approximate 98 basis points decrease in interest rates offset in part by net unrealized losses related to other market factors, primarily from widening of credit spreads.

        Fixed maturities classified as available-for-sale are subject to impairment reviews. When evaluating fixed maturities for impairment, we consider relevant facts and circumstances in evaluating whether a credit or interest-related impairment is other than temporary. Relevant facts and circumstances considered include: (1) the extent and length of time the fair value has been below cost; (2) the reasons for the decline in value; (3) the financial position and access to capital of the issuer, including the current and future impact of any specific events; (4) for structured securities, the adequacy of the expected cash flows and (5) our intent to sell a security or whether it is more likely than not we will be

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required to sell the security before recovery of its amortized cost which, in some cases, may extend to maturity. When it is determined that the decline in value is other than temporary the carrying value of the security is reduced to its fair value, and a corresponding impairment loss is reported primarily in net income, with noncredit impairment losses for certain fixed maturities we do not intend to sell reported in other comprehensive income.

        There are a number of significant risks and uncertainties inherent in the process of monitoring impairments and determining if an impairment is other than temporary. These risks and uncertainties include: (1) the risk that our assessment of an issuer's ability to meet all of its contractual obligations will change based on changes in the credit characteristics of that issuer; (2) the risk that the economic outlook will be worse than expected or have more of an impact on the issuer than anticipated; (3) the risk that our investment professionals are making decisions based on fraudulent or misstated information in the financial statements provided by issuers and (4) the risk that new information obtained by us or changes in other facts and circumstances lead us to change our intent to hold the security until it recovers in value. Any of these situations could result in a charge to net income in a future period. At December 31, 2012, we had $4,996.9 million in available-for-sale fixed maturities with gross unrealized losses totaling $871.1 million. Included in the gross unrealized losses are losses attributable to both movements in market interest rates as well as movement in credit spreads. Net income would be reduced by approximately $871.1 million, on a pre-tax basis, if all the securities in an unrealized loss position were deemed to be other than temporarily impaired and our intent was to sell all such securities.

        Mortgage Loans.    Mortgage loans consist primarily of commercial mortgage loans. At December 31, 2012, the carrying value of our commercial mortgage loans was $10,183.3 million. Commercial mortgage loans are generally reported at cost adjusted for amortization of premiums and accrual of discounts, computed using the interest method and net of valuation allowances.

        Commercial mortgage loans are considered impaired when, based on current information and events, it is probable that we will be unable to collect all amounts due according to contractual terms of the loan agreement. When we determine that a loan is impaired, a valuation allowance is created for the difference between the carrying amount of the mortgage loan and the estimated value less cost to sell. Estimated value is based on either the present value of the expected future cash flows discounted at the loan's effective interest rate, the loan's observable market price or the fair value of the collateral.

        The determination of the calculation and the adequacy of the mortgage loan valuation allowance and mortgage impairments are subjective. Our periodic evaluation and assessment of the adequacy of the mortgage loan valuation allowance and the need for mortgage impairments is based on known and inherent risks in the portfolio, adverse situations that may affect the borrower's ability to repay, the estimated value of the underlying collateral, composition of the loan portfolio, current economic conditions, loss experience and other relevant factors. The calculation for determining mortgage impairment amounts requires estimating the amounts and timing of future cash flows expected to be received on specific loans, estimating the value of the collateral and gauging changes in the economic environment in general. The total valuation allowance can be expected to increase when economic conditions worsen and decrease when economic conditions improve. For more detailed information concerning mortgage loan valuation allowances and impairments, see "Investments — U.S. Investment Operations — Mortgage Loans," and Item 8. "Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 4, Investments — Mortgage Loan Valuation Allowance."

        We have a large experienced commercial real estate staff centrally located in Des Moines, which includes commercial mortgage underwriters, loan closers, loan servicers, engineers, appraisers, credit analysts, research staff, legal staff, information technology personnel and portfolio managers. Experienced commercial real estate senior management adheres to a disciplined process in reviewing all transactions for approval on a consistent basis. The typical commercial mortgage loan for us averages in the mid 48% percent loan-to-value range at origination with a net operating income coverage ratio of 3.2 times the annual debt service and is internally rated A+ on a bond equivalent basis. Based on the most recent analysis, our commercial mortgage loan portfolio, excluding mortgage loans held in our Principal Global Investors segment, has an overall loan-to-value ratio of 54% with a 2.2 times debt service coverage. The large equity cushion and strong debt service coverage in our commercial mortgage investments will help insulate us from stress during times of weak commercial real estate fundamentals.

Derivatives

        We primarily use derivatives to hedge or reduce exposure to market risks. The fair values of exchange-traded derivatives are determined through quoted market prices. The fair values of over-the-counter derivative instruments are determined using either pricing valuation models that utilize market observable inputs or broker quotes. On an absolute fair value basis, 92% of our over-the-counter derivative assets and liabilities are valued using pricing valuation models, while the remaining 8% are valued using broker quotes. See Item 8. "Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 14, Fair Value Measurements" for further discussion. The fair values of our derivative instruments can be impacted by changes in interest rates, foreign exchange rates, credit spreads, equity indices, and volatility, as well as other contributing factors.

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        We also issue certain annuity contracts and other insurance contracts that include embedded derivatives that have been bifurcated from the host contract. They are valued using a combination of historical data and actuarial judgment. See Item 8. "Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 14, Fair Value Measurements" for further discussion. We include our assumption for own non-performance risk in the valuation of these embedded derivatives. As our credit spreads widen or tighten, the fair value of the embedded derivative liabilities decrease or increase, leading to an increase or decrease in net income. If the current market credit spreads reflecting our own creditworthiness move to zero (tighten), the reduction to net income would be approximately $10.7 million, net of DPAC and income taxes, based on December 31, 2012, reported amounts. The use of risk margins for the valuation of embedded derivatives increases the fair value of the embedded derivative liabilities.

        The accounting for derivatives is complex and interpretations of the applicable accounting standards continue to evolve. Judgment is applied in determining the availability and application of hedge accounting designations and the appropriate accounting treatment. Judgment and estimates are used to determine the fair value of some of our derivatives. Volatility in net income can result from changes in fair value of derivatives that do not qualify or are not designated for hedge accounting and changes in fair value of embedded derivatives.

Deferred Policy Acquisition Costs and Other Actuarial Balances

        Incremental direct costs of contract acquisition as well as certain costs directly related to acquisition activities (underwriting, policy issuance and processing, medical and inspection and sales force contract selling) for the successful acquisition of new and renewal insurance policies and investment contract business are capitalized to the extent recoverable. Maintenance costs and acquisition costs that are not deferrable are charged to net income as incurred.

        Amortization Based on Estimated Gross Profits.    DPAC for universal life-type insurance contracts, participating life insurance policies and certain investment contracts are amortized over the expected lifetime of the policies in relation to estimated gross profits ("EGPs"). In addition to DPAC, the following actuarial balances are also amortized in relation to EGPs.

•

Sales inducement asset — Sales inducements are amounts that are credited to the contractholder's account balance as an inducement to purchase the contract. Like DPAC, the cost of the sales inducement is capitalized and amortized over the expected life of the contract, in proportion to EGPs.



•

Unearned revenue liability — An unearned revenue liability is established when we collect fees or other policyholder assessments that represent compensation for services to be provided in future periods. These revenues are deferred and then amortized over the expected life of the contract, in proportion to EGPs.



•

Reinsurance asset or liability — For universal-life type products that are reinsured, a reinsurance asset or liability is established to spread the expected net reinsurance costs or profits in proportion to the EGPs on the underlying business.



•

Present value of future profits ("PVFP") — This is an intangible asset that arises in connection with the acquisition of a life insurance company or a block of insurance business. PVFP for universal life-type insurance contracts, participating life insurance policies and certain investment contracts is amortized over the expected life of the contracts acquired, in proportion to EGPs.

        We also have additional benefit reserves that are established for annuity or universal life-type contracts that provide benefit guarantees, or for contracts that are expected to produce profits followed by losses. The liabilities are accrued in relation to estimated contract assessments.

        We define EGPs to include assumptions relating to mortality, morbidity, lapses, investment yield and expenses as well as the change in our liability for certain guarantees and the difference between actual and expected reinsurance premiums and recoveries, depending on the nature of the contract. We develop an estimate of EGPs at issue and each valuation date. As actual experience emerges, the gross profits may vary from those expected either in magnitude or timing, in which case a true-up to actual occurs as a charge or credit to current net income. In addition, we are required to revise our assumptions regarding future experience if actual experience or other evidence suggests that earlier estimates should be revised; we refer to this as unlocking. Both actions, reflecting actual experience and changing future estimates, can change both the current amount and the future amortization pattern of the DPAC asset and related actuarial balances.

        For individual variable life insurance, individual variable annuities and group annuities that have separate account U.S. equity investment options, we utilize a mean reversion methodology (reversion to the mean assumption), a common industry practice, to determine the future domestic equity market growth rate assumption used for the calculation of EGPs. If actual annualized U.S. equity market performance varies from our 8% long-term assumption, we assume different performance levels in the short-term such that the mean return is equal to the long-term assumption over the mean reversion period. However, our mean reversion process generally limits assumed returns to a range of 4 - 12% during the mean reversion period. The 12% cap was reached during the third quarter of 2008, and the mean reversion rate has remained at the 12% cap since then. Therefore, until the mean reversion rate falls below the 12% cap, we will not adjust the equity return assumption by the amount needed to result in a mean return equal to the long-term assumption.

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        In limited circumstances, DPAC and certain of the actuarial balances noted above are amortized in proportion to estimated gross revenues rather than EGPs. Estimated gross revenues include similar assumptions as the revenue component of EGPs and the changes of future estimates and reflection of actual experience is done in the same manner as EGPs discussed above.

        Amortization Based on Premium-Paying Period.    DPAC of non-participating term life insurance and individual disability policies are amortized over the premium-paying period of the related policies using assumptions consistent with those used in computing policyholder liabilities. Once these assumptions are made for a given policy or group of policies, they will not be changed over the life of the policy unless a loss recognition event occurs. As of December 31, 2012, these policies accounted for 15% of our total DPAC balance.

        Internal Replacements.    We review policies for modifications that result in the exchange of an existing contract for a new contract. If the new contract is determined to be an internal replacement that is substantially changed from the replaced contract, any unamortized DPAC and related actuarial balances are written off and acquisition costs related to the new contract are capitalized as appropriate. If the new contract is substantially unchanged, we continue to amortize the existing DPAC and related actuarial balances.

        Recoverability.    DPAC and sales inducement assets are subject to recoverability testing at the time of policy issue and loss recognition testing on an annual basis, or when an event occurs that may warrant loss recognition. Likewise, PVFP is subject to impairment testing on an annual basis, or when an event occurs that may warrant impairment. If loss recognition or impairment is necessary, the asset balances are written off to the extent that it is determined that future policy premiums and investment income or gross profits are not adequate to cover related losses and expenses.

        Sensitivities.    As of December 31, 2012, the net balance of DPAC and related actuarial balances, excluding balances affected by changes in other comprehensive income, was a $2,354.9 million asset. We perform sensitivity analyses to assess the impact that certain assumptions have on our DPAC and related actuarial balances. The following table shows the estimated immediate impact of various assumption changes on our DPAC and related actuarial balances.

Goodwill and Other Intangible Assets

        Goodwill and other intangible assets include the cost of acquired subsidiaries in excess of the fair value of the net tangible assets recorded in connection with acquisitions. Goodwill and intangible assets with indefinite lives are not amortized; rather, we test the carrying value for impairment at least annually at the reporting unit level, which is a business one level below the operating segment. We formally conduct our annual goodwill and other intangible asset impairment testing during the fourth quarter. Under certain circumstances, interim impairment tests may be required if events occur or circumstances change that would more likely than not reduce the fair value of a reporting unit below its carrying value. See Item 8. "Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 1, Nature of Operations and Significant Accounting Policies" for further discussion.

        We perform a two-step test in our evaluation of the carrying value of goodwill. In Step 1 of the evaluation, the fair value of each reporting unit is determined and compared to the carrying value of the reporting unit. If the fair value is greater than the carrying value, then the carrying value of the reporting unit is deemed to be recoverable, and Step 2 is not required. If the fair value estimate is less than the carrying value, it is an indicator that impairment may exist, and Step 2 is required. In Step 2, the reporting unit's goodwill implied fair value is determined. The reporting unit's fair value as determined in Step 1 is assigned to all of its net assets (recognized and unrecognized) as if the reporting unit were acquired in a business combination as of the date of the impairment test. If the implied fair value of the reporting unit's goodwill is lower than its carrying amount, goodwill is impaired and written down to its implied fair value.

        The determination of fair value for our reporting units is primarily based on an income approach whereby we use discounted cash flows for each reporting unit. When available, and as appropriate, we use market approaches or other valuation techniques to corroborate discounted cash flow results. The discounted cash flow model used for each reporting unit is based on either income or distributable cash flow, depending on the reporting unit being valued.

        For the income model, we determine fair value based on the present value of the most recent income projections for each reporting unit and calculate a terminal value utilizing a terminal growth rate. The significant assumptions in the

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operating income model include: income projections, including the underlying assumptions; discount rate and terminal growth rate.

        For the distributable cash flow model, we determine fair value based on the present value of projected statutory net income and changes in required capital to determine distributable income for the respective reporting unit. The significant assumptions in the distributable cash flow model include: required capital levels; income projections, including the underlying assumptions; discount rate; new business projection period and new business production growth.

        Intangible assets with useful lives are amortized as related benefits emerge and are reviewed periodically for indicators of impairment in value. If facts and circumstances suggest possible impairment, the sum of the estimated undiscounted future cash flows expected to result from the use of the asset is compared to the current carrying value of the asset. If the undiscounted future cash flows are less than the carrying value, an impairment loss is recognized for the excess of the carrying amount of assets over their fair value. For those assets amortized as related benefits emerge, the most significant assumptions involved in the estimation of future benefits include surrender/lapse rates, interest margins and mortality.

        We did not recognize a material impairment in our 2012 consolidated statement of operations. Investment management contracts acquired in our 2006 purchase of WM Advisors, Inc. are considered an indefinite lived intangible and are the most material intangible asset included in our 2012 consolidated statement of financial position with a carrying value of $608.0 million. Positive net cash flows and expected future flows combined with significantly lower than expected expenses more than offset lower than expected market returns on the underlying assets acquired. As a result, the fair value of this intangible asset as of December 31, 2012, was in excess of its carrying value. We cannot predict certain future events that might adversely affect the reported value of goodwill and other intangible assets that totaled $543.4 million and $927.2 million, respectively, as of December 31, 2012. Such events include, but are not limited to, strategic decisions made in response to economic and competitive conditions, the impact of the economic environment on our customer base, interest rate movements, declines in the equity markets, the legal environment in which the businesses operate or a material negative change in our relationships with significant customers. Additional information about impairments is described in Item 8. "Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 2, Goodwill and Other Intangible Assets."

Insurance Reserves

        Reserves are liabilities representing estimates of the amounts that will come due, at some point in the future, to or on behalf of our policyholders. U.S. GAAP, allowing for some degree of managerial judgment, prescribes the methods of establishing reserves.

        Future policy benefits and claims include reserves for individual traditional and group life insurance, accident and health insurance and individual and group annuities that provide periodic income payments, which are computed using assumptions of mortality, morbidity, lapse, investment performance and expense. These assumptions are based on our experience and are periodically reviewed against industry standards to ensure actuarial credibility. For long duration insurance contracts, once these assumptions are made for a given policy or group of policies, they will not be changed over the life of the policy. However, significant changes in experience or assumptions may require us to provide for expected future losses on a product by establishing premium deficiency reserves. Premium deficiency reserves may also be established for short duration contracts to provide for expected future losses. Our reserve levels are reviewed throughout the year using internal analysis including, among other things, experience studies, claim development analysis and annual statutory asset adequacy analysis. To the extent experience indicates potential loss recognition, we recognize losses on certain lines of business. The ultimate accuracy of the assumptions on these long-tailed insurance products cannot be determined until the obligation of the entire block of business on which the assumptions were made is extinguished. Short-term variances of actual results from the assumptions used in the computation of the reserves are reflected in current period net income and can impact quarter-to-quarter net income.

        Future policy benefits and claims also include reserves for incurred but unreported health, disability and life insurance claims. We recognize claims costs in the period the service was provided to our policyowners. However, claims costs incurred in a particular period are not known with certainty until after we receive, process and pay the claims. We determine the amount of this liability using actuarial methods based on historical claim payment patterns as well as emerging medical cost trends, where applicable, to determine our estimate of claim liabilities. We also look back to assess how our prior periods' estimates developed. To the extent appropriate, changes in such development are recorded as a change to current period claim expense. Historically, the amount of the claim reserve adjustment made in subsequent reporting periods for prior period estimates have been within a reasonable range given our normal claim fluctuations.

Benefit Plans

        The reported expense and liability associated with pension and other postretirement benefit plans requires the use of assumptions. Numerous assumptions are made regarding the discount rate, expected long-term rate of return on plan assets, turnover, expected compensation increases, health care claim costs, health care cost trends, retirement rates and mortality. The discount rate and the expected return on plan assets have the most significant impact on the level of expense.

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        The assumed discount rate is determined by projecting future benefit payments inherent in the Projected Benefit Obligation and discounting those cash flows using a spot yield curve for high quality corporate bonds. Our assumed discount rate for the 2012 year-end was 4.00%. Typically a 0.25% decrease in the discount rate would increase the pension benefits Projected Benefit Obligation and the Net Periodic Pension Cost ("NPPC") by approximately $99.3 million and $13.6 million, respectively. Typically a 0.25% decrease in the discount rate would increase the other postretirement benefits Accumulated Postretirement Benefit Obligation by approximately $3.6 million and would have a nominal impact on the Net Periodic Benefit Cost ("NPBC"). Typically a 0.25% increase in the discount rate would result in decreases in benefit obligations and expenses at a level generally commensurate with those noted above.

        The assumed long-term rate of return on plan assets is set at the long-term rate expected to be earned based on the long-term investment policy of the plans and the various classes of the invested funds. Historical and future expected returns of multiple asset classes were analyzed to develop a risk-free real rate of return and risk premiums for each asset class. The overall long-term rate for each asset class was developed by combining a long-term inflation component, the real risk free rate of return and the associated risk premium. A weighted average rate was developed based on long-term returns for each asset class, the plan's target asset allocation policy and the tax structure of the trusts. For the 2012 NPPC and 2012 NPBC, an 8.00% and 7.30% weighted average long-term rate of return was used, respectively. For the 2013 NPPC and 2013 NPBC, a 7.50% and 5.62% weighted average long-term rate of return assumption, respectively, will be used. Typically a 0.25% decrease in the assumed long-term rate of return would increase the NPPC by approximately $4.2 million and the NPBC by approximately $1.3 million. Typically a 0.25% increase in this rate would result in a decrease to expense at the same levels. The assumed return on plan assets is based on the fair market value of plan assets as of December 31, 2012.

        The compensation increase assumption is generally set at a rate consistent with current and expected long-term compensation and salary policy, including inflation. Actuarial gains and losses are amortized using a straight-line amortization method over the average remaining service period of employees, which is approximately 7 years for pension costs and approximately 11 years for other postretirement benefit costs. Prior service costs are amortized on a weighted average basis over approximately 2 years for pension and 3 years for other postretirement benefit costs. See Item 8. "Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 11, Employee and Agent Benefits" for further discussion.

Income Taxes

        We provide for income taxes based on our estimate of the liability for taxes due. Our tax accounting represents management's best estimate of various events and transactions, such as completion of tax audits or establishment of, or changes to, a valuation allowance associated with certain deferred tax assets, which could affect our estimates and effective income tax rate in a particular quarter or annual period. Deferred tax liabilities and assets are determined based on the difference between the financial statement and tax bases of assets and liabilities using enacted tax rates expected to be in effect during the years in which the basis differences reverse. We are required to evaluate the recoverability of our deferred tax assets each quarter and establish a valuation allowance, if necessary, to reduce our deferred tax assets to an amount that is more-likely-than-not to be realizable. In determining the need for a valuation allowance, we consider many factors, including future reversals of existing taxable temporary differences, future taxable income exclusive of reversing temporary differences and carryforwards, taxable income in prior carryback years and implementation of any feasible and prudent tax planning strategies management would employ to realize the tax benefit.

        Inherent in the provision for income taxes are estimates regarding the deductibility of certain items, the timing of income and expense recognition and the current or future realization of operating losses, capital losses and certain tax credits. In the event these estimates differ from our prior estimates due to the receipt of new information, we may be required to significantly change the provision for income taxes recorded in the consolidated financial statements. Any such change could significantly affect the amounts reported in the consolidated financial statements in the year these estimates change. A further significant decline in value of assets incorporated into our tax planning strategies could lead to an increase of our valuation allowance on deferred tax assets having an adverse effect on current and future results. In management's judgment, total deferred income tax assets are more likely than not to be realized.

        In addition, the amount of income taxes paid is subject to audits in U.S. as well as various state and foreign jurisdictions. Tax benefits are recognized for book purposes when the more-likely-than-not threshold is met with regard to the validity of an uncertain tax position. Once this threshold is met, for each uncertain tax position we recognize in earnings the largest amount of benefit that is greater than 50% likely of being realized upon ultimate settlement with the Internal Revenue Service or other income taxing authorities for audits ongoing or not yet commenced.

        We had $334.6 million and $263.2 million of current income tax receivables associated with outstanding audit issues reported as other assets in our consolidated statements of financial position as of December 31, 2012 and 2011, respectively. We believe that we have adequate defenses against, or sufficient provisions for, the contested issues, but final resolution of contested issues could take several years while legal remedies are pursued. Consequently, we do not anticipate the ultimate resolution of audits ongoing or not yet commenced to have a material impact on our net income.

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Transactions Affecting Comparability of Results of Operations

Acquisitions

        We entered into acquisition agreements for the following businesses, among others, during the past three years.

        First Dental Health.    On November 1, 2012, we finalized the purchase of our 100% interest in First Dental Health, a California based independent dental preferred provider organization. First Dental Health is consolidated within the U.S. Insurance Solutions segment.

        AFP Cuprum S.A.    On October 8, 2012, we announced the signing of a definitive agreement to acquire Cuprum, a premier pension manager in Chile. The agreement required Empresas Penta S.A. and Inversiones Banpenta Limitada to sell their 63% ownership in Cuprum pursuant to a public tender offer that also included the remaining 37% of publicly traded shares. The transaction closed February 4, 2013, resulting in an approximately 90% ownership stake in Cuprum for a purchase price of approximately $1.4 billion. Cuprum will be consolidated within the Principal International segment.

        Claritas Administração de Recursos Ltda./Claritas Investments, Ltd.    On April 2, 2012, we finalized the purchase of a 60% indirect ownership in Claritas, a leading Brazilian mutual fund and asset management company. The Sao Paulo-based company manages equity funds, balanced funds, managed accounts and other strategies for affluent clients and institutions through its multi-channel distribution network. Claritas had $1.8 billion in AUM at the time of acquisition and is consolidated within the Principal International segment.

        Origin Asset Management LLP.    On October 3, 2011, we finalized the purchase of a 74% interest in Origin Asset Management LLP ("Origin"), a global equity specialist based in London. The initial payment was $63.6 million. Origin had $2.6 billion in AUM in global and international equities at the time of the acquisition and is consolidated within the Principal Global Investors segment.

        HSBC AFORE, S.A. de C.V.    On August 8, 2011, we finalized the purchase of our 100% interest in HSBC AFORE, S.A. de C.V. ("HSBC AFORE"), a Mexican pension business, from HSBC Bank for $206.1 million. In addition, we have established a distribution arrangement with HSBC Bank for the distribution of Principal AFORE's products through HSBC Bank's extensive network in Mexico. HSBC AFORE was merged into our Principal AFORE pension company, which is consolidated within the Principal International segment.

        Finisterre Capital LLP and Finisterre Holdings Limited.    On July 1, 2011, we finalized the purchase of a 51% interest in Finisterre Capital LLP and Finisterre Holdings Limited, (together "Finisterre Capital"), an emerging markets debt investor based in London. The initial payment was $84.6 million, with a possible additional contingent payment of up to $30.0 million in 2013, dependent upon performance targets. Finisterre Capital had $1.7 billion in AUM at the time of acquisition and is accounted for on the equity method within the Principal Global Investors segment.

Other

        Actuarial Assumption Updates.    During the third quarter of 2012, we reviewed and updated assumptions that are inputs to the models for DPAC and other actuarial balances. We also reviewed our actuarial models and made improvements as necessary. As a result of these actions, we had an unlocking of DPAC and other actuarial balances that decreased total company net income by $96.7 million for the year ended December 31, 2012.

        We updated our actuarial models to reflect the lower interest rate environment in our U.S. operations. The updates to our long-term interest rate assumptions and related refinements to the interest rate component of our actuarial models resulted in an unlocking that negatively impacted operating earnings. The negative unlocking from the lower interest rates was partially offset by the positive impact from the increased expected persistency in our individual annuities business. The net negative segment operating earnings impact was $66.3 million, which was comprised of $55.2 million for our U.S. Insurance Solutions segment and $11.1 million for our Retirement and Investor Services segment.

        In addition to the interest rate assumption update, we updated other assumptions and made model refinements that resulted in a net negative unlocking and a $24.4 million decrease to operating earnings in total for the Retirement and Investor Services, Principal International and U.S. Insurance Solutions segments for the year ended December 31, 2012.

        Within our individual life insurance business, we have an integrated actuarial model that impacts several line items within our income statement. Operating earnings for the individual life insurance business was negatively impacted $62.9 million for the year ended December 31, 2012. The impact on the income statement line items was as follows — fee revenues increased $13.5 million; benefits, claims and settlement expenses increased $67.2 million; and operating expenses increased $43.0 million.

        Catalyst Health Solutions, Inc.    In July 2012, Catalyst Health Solutions, Inc. merged with a wholly owned subsidiary of SXC Health Solutions Corp. As a result of the merger, we realized an after-tax gain. We subsequently contributed appreciated stock of the ultimate surviving corporation (now known as Catamaran Corp.) to The Principal Financial Group Foundation, Inc. and sold our remaining interest in Catamaran Corp., resulting in a total after-tax net realized capital gain of $141.2 million.

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        Individual Life Insurance Amortization.    During the first quarter of 2012, our individual life insurance business changed its basis for amortizing DPAC and other actuarial balances on a portion of our universal life insurance products. The actuarial balances for these products are now amortized based on estimated gross revenues instead of EGPs. In addition to impacting comparability of changes in actuarial balances between 2011 and 2012, this change required an unlocking of the actuarial balances to reflect the pattern of estimated gross revenues, which resulted in volatility within certain income statement line items in the first quarter of 2012. Specifically, fee revenues decreased $46.6 million; benefits, claims and settlement expenses increased $87.9 million; and operating expenses decreased $139.6 million. However, on a net basis the impact was a net gain of $3.3 million after-tax, which is not material.

        Individual Life Insurance Assumption Changes.    During the second quarter of 2011, we updated premium assumptions in our individual life insurance business, which impacts comparability between reported time periods. Specifically, fee revenues increased $4.9 million; benefits, claims and settlement expenses increased $43.1 million; and operating expenses increased $14.9 million. Given the large magnitude of the assumption changes, we removed the after-tax impact of $(34.5) million from operating earnings and reported it as an other after-tax adjustment in order to aid in comparability at the segment level.

        Catalyst Health Solutions, Inc.    In early April 2011, we sold a portion of our interest in Catalyst Health Solutions,  Inc., which was accounted for on the equity method. The $46.0 million after-tax gain was reported as a net realized capital gain in the second quarter of 2011. The remaining portion of the investment continued to be accounted for as an equity method investment.

        Individual Life Interest Rate Assumption Change.    During the fourth quarter of 2010, we lowered our long term interest rate assumption, which negatively impacted operating earnings by $6.8 million. Fee revenues increased $7.4 million; benefits, claims and settlement expenses decreased $4.6 million and operating expenses increased $22.5 million.

        Group Medical Insurance Business.    On September 30, 2010, we announced our decision to exit the group medical insurance business (insured and administrative services only) and entered into an agreement with United Healthcare Services, Inc. to renew group medical insurance coverage for our customers as the business transitions. The exiting of the group medical insurance business does not qualify for discontinued operations treatment under U.S. GAAP. Therefore, the results of operations for the group medical insurance business are still included in our consolidated income from continuing operations.

        With the exception of corporate overhead, amounts related to our group medical insurance business previously included in segment operating earnings have been removed from operating earnings for all periods presented and are reported as other after-tax adjustments. The operating revenues associated with our exited group medical insurance business were $25.0 million, $606.3 million and $ 1,403.9 million for the year ended December 31, 2012, 2011 and 2010, respectively. The other after-tax adjustments associated with the after-tax earnings (loss) of our exited group medical insurance business were $(9.6) million, $50.9 and $24.0 million for the years ended December 31, 2012, 2011 and 2010, respectively.

        Brasilprev Seguros e Previdencia S.A.    On April 30, 2010, we signed definitive agreements with Banco, including the Shareholders Agreement governing the operations of our pension joint venture, Brasilprev. The agreements result in Brasilprev having, for 23 years, the exclusive right to distribute pension products within the Banco bank network and a reduction in our economic interest from 46% to 25%, which resulted in a $72.1 million after-tax net realized capital gain in the second quarter of 2010. Brasilprev continues to be jointly managed and reported as an equity method investment in our Principal International segment. Due to the reduction in our economic interest, we reflect a lower percentage of the earnings from the operation. However, we expect the operation to grow and offset the decline from the lower percentage.

Fluctuations in Foreign Currency to U.S. Dollar Exchange Rates

        Fluctuations in foreign currency to U.S. dollar exchange rates for countries in which we have operations can affect reported financial results. In years when foreign currencies weaken against the U.S. dollar, translating foreign currencies into U.S. dollars results in fewer U.S. dollars to be reported. When foreign currencies strengthen, translating foreign currencies into U.S. dollars results in more U.S. dollars to be reported.

        Foreign currency exchange rate fluctuations create variances in our financial statement line items but have not had a material impact on our consolidated financial results. Principal International segment operating earnings were negatively impacted by $16.6 million for the year ended December 31, 2012, as a result of fluctuations in foreign currency to U.S. dollar exchange rates. For a discussion of our approaches to managing foreign currency exchange rate risk, see Item 3. "Quantitative and Qualitative Disclosures About Market Risk — Foreign Currency Risk."

Stock-Based Compensation Plans

        For information related to our Stock-Based Compensation Plans, see Item 8. "Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 17, Stock-Based Compensation Plans."

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Effects of Inflation

        The impact of inflation has not had a material effect on our annual consolidated results of operations over the past three years. However, we may be materially affected by inflation in the future. For further discussion on inflation, see Item 1A. "Risk Factors — Continued difficult conditions in the global capital markets and the economy generally may materially and adversely affect our business and results of operations."

Employee and Agent Benefits Expense

        The 2012 annual defined benefit pension expense for substantially all of our employees and certain agents was $122.3 million pre-tax, which was a $29.5 million increase from the 2011 pre-tax pension expense of $92.8 million. This increase is due primarily to a decline in the discount rate from 5.65% for 2011 to 5.15% for 2012. The expected long-term return on plan assets used to develop the 2012 expense remained at the same 8.00% as for 2011.

        The 2013 annual defined benefit pension expense for substantially all of our employees and certain agents is expected to be $143.3 million pre-tax, which is a $21.0 million increase from the 2012 pre-tax pension expense of $122.3 million. This increase is due primarily to a decrease in the discount rate from 5.15% for 2012 to 4.00% for 2013. Also, the expected long-term return on plan assets used to develop the 2013 expense decreased to 7.50%.

        The 2012 annual other postemployment benefit ("OPEB") plan expense (income) for employees and certain agents was $(55.2) million pre-tax, which is a $2.8 million difference from the 2011 pre-tax OPEB income of $(58.0) million. The weighted average expected long-term return on plan assets used to develop the expense (income) in 2012 was 7.30% which was based on the weighted average expected long-term asset returns for the medical, life and long-term care plan. The expected long-term rates for the medical, life and long-term care plans were 7.25%, 7.75%, and 5.85%, respectively. The discount rate used to develop the 2012 expense (income) was 5.15%.

        The 2013 annual OPEB plan expense (income) for employees and certain agents is expected to be $(47.0) million pre-tax, which is an $8.2 million difference from the 2012 pre-tax OPEB income of $(55.2) million. The weighted average expected long-term return on plan assets used to develop the expense (income) in 2013 was 5.62% which was based on weighted average expected long-term asset returns for the medical, life and long-term care plan. The expected long-term rates for the medical, life and long-term care plans were 5.40%, 7.75% and 5.85%, respectively. The expected rate of return for the medical plans was reduced to 5.40% to reflect the after-tax return on the plan assets resulting from the decision to have taxes paid by the trust instead of PLIC. The discount rate used to develop the 2013 expense (income) decreased to 4.00%, down from the 5.15% discount rate used in 2012.

Healthcare Reform

        During the first quarter of 2010, federal legislation was enacted that reformed the healthcare system. Among many changes, the newly enacted healthcare legislation eliminates the tax deductibility of retiree prescription drug expenses incurred after 2012, up to the Medicare Part D subsidy amount, which had been allowed to encourage employers to offer retiree drug coverage. We recognized $7.8 million negative impact of net income for the year ended December 31, 2010, associated with the release of the portion of our deferred tax asset on accrued retiree prescription drug expenses related to our employees that will no longer be tax-deductible after December 31, 2012.

Impact of Low Interest Rate Environment

        The exposure from the low interest rates is reflected in a reduction in the spreads between the investment income we earn and the interest we credit to our customers. Some of our products, primarily our fixed deferred annuity, general account group annuity and universal life insurance products, include guaranteed minimum interest rates. During periods of low or declining interest rates, borrowers may prepay or redeem mortgages and fixed maturities that are invested to support our product obligations, which would force us to reinvest the proceeds at lower interest rates. The resulting lower net investment income may make it more difficult for us to maintain our desired spread and thereby reduce our profitability. See Item 7A "Quantitative and Qualitative Disclosures About Market Risk," for a presentation of the differences between the interest rates being credited to contractholders and the respective guaranteed minimum interest rates.

        Some of our universal life insurance contracts contain secondary guarantees, which keep the contract in force, even if the contractholder's account balance is insufficient to cover all of the contract charges, provided that the contractholder has continually paid a specified minimum premium. It is possible that more of these secondary guarantees could be triggered, possibly increasing our policyholder obligation and thereby reducing our profitability.

        Declining or low interest rates could impact the discount rate assumption used for the purposes of valuing reserves and our pension and other postretirement benefit obligations. A decrease in the discount rate could result in higher reserves as well as lower margins and an increase in the annual pension and other postretirement benefit expense.

        Our expectation of estimated gross profits is an important consideration in determining the amortization of DPAC and other actuarial balances. To the extent a low interest rate environment impacts our assumptions regarding future EGPs, an unlocking of DPAC and other actuarial balances could occur, decreasing net income.

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        Lastly, lower net investment income could result in the establishment of a premium deficiency reserve for certain of our insurance products.

        We anticipate that a sustained low interest rate environment would reduce the growth in net income.

Recent Accounting Changes

        For recent accounting changes, see Item 8. "Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 1, Nature of Operations and Significant Accounting Policies" under the captions, "Accounting Changes" and "Recent Accounting Pronouncements."

Results of Operations

        The following table presents summary consolidated financial information for the years indicated:

Year Ended December 31, 2012 Compared to Year Ended December 31, 2011

Net Income Available to Common Stockholders

        Net income available to common stockholders increased primarily due to higher gains associated with the merger of Catalyst Health Solutions, Inc. and the subsequent disposition of our remaining interest in the surviving corporation in 2012 compared to the portion of our interest sold in 2011 and a negative impact of a court ruling on some uncertain tax positions in 2011 with no corresponding activity in 2012.

Total Revenues

        Premiums increased $772.2 million for the Retirement and Investor Services segment primarily due to an increase in sales of single premium group annuities with life contingencies. The single premium product, which is typically used to fund defined benefit plan terminations, can generate large premiums from very few customers and therefore tends to vary from period to period. Partially offsetting this increase was a $509.2 million decrease for the Corporate segment primarily due to a reduction in average covered medical members in our exited group medical insurance business.

        Fee revenues increased $93.3 million for our Retirement and Investor Services segment primarily due to higher fees stemming from an increase in average account values, which resulted from positive equity market performance in 2012 and strong net cash flow from customers. Fee revenues also increased $48.4 million for our Principal International segment primarily due to higher investment management fees driven by higher average AUM in Mexico and the Claritas acquisition in Brazil. In addition, fees increased $44.6 million for our Principal Global Investors segment primarily due to

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higher fee revenues as a result of increased AUM. Partially offsetting these increases was an $86.3 million decrease in fee revenues for the Corporate segment primarily due to a reduction in average fee-for-service members in our exited group medical insurance business.

        Net investment income decreased due to lower investment yields on our invested assets and cash in our U.S. operations, and lower inflation-based investment returns on average invested assets and cash as a result of lower inflation in Chile and the weakening of the Latin American currencies against the U.S. dollar. These decreases were partially offset by an increase in average invested assets and cash. For additional information, see "Investments — Investment Results."

        Net realized capital gains (losses) can be volatile due to other than temporary impairments of invested assets, mark-to-market adjustments of certain invested assets and our decision to sell invested assets. Net realized capital gains (losses) increased primarily due to higher gains associated with the merger of Catalyst Health Solutions, Inc. and the subsequent disposition of our remaining interest in the surviving corporation in 2012 compared to the portion of our interest sold in 2011 and a decrease in credit impairments on fixed maturities, available-for-sale. For additional information, see "Investments — Investment Results."

Total Expenses

        Benefits, claims and settlement expenses increased $695.8 million for the Retirement and Investor Services segment primarily due to an increase in change in reserves resulting from an increase in sales of single premium group annuities with life contingencies. Benefits, claims and settlement expenses also increased $210.4 million for the U.S. Insurance Solutions segment primarily due to the change in amortization basis, unlocking associated with a change in our long-term interest rate assumptions and model refinements in the third quarter of 2012 and growth in our individual life insurance business. Partially offsetting these increases was a $384.4 million decrease in benefits, claims and settlement expenses for the Corporate segment primarily due to a reduction in average covered medical members in our exited group medical insurance business.

Income Taxes

        The effective income tax rates were 14% and 23% for the years ended December 31, 2012 and 2011, respectively. The effective income tax rate for the year ended December 31, 2012 was lower than the U.S. corporate income tax rate of 35% ("U.S. statutory rate") primarily due to income tax deductions allowed for corporate dividends received, the presentation of taxes on our share of earnings generated from equity method investments in net investment income and the interest exclusion from taxable income. The effective income tax rate for the year ended December 31, 2011, was lower than the U.S. statutory rate primarily due to income tax deductions allowed for corporate dividends received, the presentation of taxes on our share of earnings generated from equity method investments in net investment income and the interest exclusion from taxable income, which were partially offset by the impact of a court ruling on some uncertain tax positions. The effective income tax rate decreased to 14% from 23% for the years ended December 31, 2012 and 2011, respectively, primarily due to the impact of a 2011 court ruling on some uncertain tax positions.

Year Ended December 31, 2011 Compared to Year Ended December 31, 2010

Net Income Available to Common Stockholders

        Net income available to common stockholders decreased primarily due to the negative impact of a court ruling on some uncertain tax positions in 2011. This decrease to net income available to common stockholders was partially offset by higher earnings in our Retirement and Investor Services, Principal International and Principal Global Investors segments.

Total Revenues

        Premiums decreased $770.3 million for the Corporate segment primarily due to a reduction in average covered medical members in our exited group medical insurance business.

        Fees increased $72.4 million for our U.S. Insurance Solutions segment primarily due to growth in the universal life and variable universal life lines of business. Fees also increased $72.3 million for our Retirement and Investor Services segment primarily due to higher fees stemming from an increase in average account values, which resulted from general positive equity market performance in 2011. In addition, fees increased $64.0 million for our Principal Global Investors segment primarily due to higher fee revenues driven by an increase in average AUM as well as increased performance fees in our equity business and higher borrower fees from our real estate business.

        Net investment income decreased due to lower investment yields and a decrease in average invested assets and cash, excluding the fair value adjustment associated with fixed maturities and equity securities, primarily due to our decision to scale back our investment only business. These decreases were partially offset by higher inflation-based investment returns on average invested assets and cash as a result of higher inflation in Chile and the strengthening of the Latin American currencies against the U.S. dollar. For additional information, see "Investments — Investment Results."

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        Net realized capital gains (losses) can be volatile due to other than temporary impairments of invested assets, mark-to market adjustments of certain invested assets and our decision to sell invested assets. Net realized capital losses decreased primarily due to a gain associated with the sale of a portion of our interest in Catalyst Health Solutions, Inc. in 2011, lower losses related to the residential mortgage loan loss provision for our Bank and Trust Services business and lower net impairment losses on fixed maturities, available-for-sale. These decreases were partially offset by a 2010 gain associated with the signing of our Shareholders Agreement with Banco pertaining to our Brasilprev joint venture with no corresponding activity in 2011. For additional information, see "Investments — Investment Results."

Total Expenses

        Benefits, claims and settlement expenses decreased $607.1 million for the Corporate segment primarily due to a reduction in average covered medical members in our exited group medical insurance business.

Income Taxes

        The effective income tax rates were 23% and 13% for the years ended December 31, 2011 and 2010, respectively. The effective income tax rate for the year ended December 31, 2011, was lower than the U.S. statutory rate primarily due to income tax deductions allowed for corporate dividends received, the presentation of taxes on our share of earnings generated from equity method investments in net investment income and the interest exclusion from taxable income, which were partially offset by the impact of a court ruling on some uncertain tax positions. The effective income tax rate for the year ended December 31, 2010, was lower than the U.S. statutory rate primarily due to income tax deductions allowed for corporate dividends received, the presentation of taxes on our share of earnings generated from equity method investments in net investment income and the interest exclusion from taxable income. The effective income tax rate increased to 23% from 13% for the years ended December 31, 2011 and 2010, respectively, primarily due to the impact of a 2011 court ruling on some uncertain tax positions.

Results of Operations by Segment

        For results of operations by segment see Item 8. "Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 16, Segment Information."

Retirement and Investor Services Segment

Retirement and Investor Services Trends

        Several key factors impact revenue and earnings growth in our Retirement and Investor Services segment. These factors include: the ability of our distribution channels to generate new sales and retain existing business; pricing decisions that take account of competitive conditions, persistency, investment returns, mortality trends, and operating expense levels; investment management performance; equity market returns and interest rate changes. Profitability ultimately depends on our ability to price products and invest assets at a level that enables us to earn a margin over the cost of providing benefits and the expense of acquiring and administering those products.

        Net revenue is a key metric used to understand RIS earnings growth. Net revenue is defined as operating revenues less benefits, claims and settlement expenses, including dividends to policyholders. Net revenue from our Accumulation business is primarily fee based and is impacted by changes in the equity markets. Net revenue from our Guaranteed business is driven by our ability to earn an investment spread. Accumulation business net revenue has grown due to growth in the block of business as well as improvement in the equity markets. Guaranteed business net revenue has declined due to our decision to scale back this business and due to investment spread compression.

        The following table presents the Retirement and Investor Services net revenue for the years indicated:

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Retirement and Investor Services Segment Summary Financial Data

        The following table presents certain summary financial data relating to the Retirement and Investor Services segment for the periods indicated:

Year Ended December 31, 2012 Compared to Year Ended December 31, 2011

Operating Earnings

        Operating earnings increased $15.5 million in our Accumulation business resulting from positive equity market performance in 2012 and strong net cash flow from customers, which was partially offset by higher staff related costs, including pension and other postretirement benefits, and higher non-deferrable commissions and investment management fees stemming from an increase in average account values. Operating earnings decreased $3.3 million in our Guaranteed business primarily resulting from lower mortality reserve gains in 2012 compared to 2011.

Net Revenue

        Net revenue increased $127.1 million in our Accumulation business primarily due to higher fees stemming from an increase in average account values, which resulted from positive equity market performance in 2012 and strong net cash flow from customers.

Operating Expenses

        Operating expenses increased $124.7 million in our Accumulation business primarily due to higher staff related costs, including pension and other postretirement benefits. In addition, operating expenses increased due to higher non-deferrable commissions and investment management fees stemming from increased sales and an increase in average account values, respectively.

Income Taxes

        The effective income tax rates for the segment were 21% and 23% for the years ended December 31, 2012 and 2011, respectively. The effective income tax rates were lower than the U.S. statutory rate primarily as a result of income tax deductions allowed for corporate dividends received and the interest exclusion from taxable income.

Year Ended December 31, 2011 Compared to Year Ended December 31, 2010

Operating Earnings

        Operating earnings increased $23.9 million in our Accumulation business resulting from higher fees stemming from generally positive equity market performance since 2010. This increase was partially offset by an increase in DPAC amortization expense resulting from mostly level equity markets in 2011, compared to improving equity markets in 2010. Operating earnings decreased $4.0 million in our Guaranteed business primarily resulting from a gain from early extinguishment of medium term notes in 2010 with no corresponding experience in 2011. This decrease was partially offset by a decrease in change in reserves resulting from a larger than normal reserve increase in the third quarter of 2010 with no corresponding activity in 2011, as well as a larger reserve release due to favorable mortality experience in 2011.

Net Revenue

        Net revenue increased $97.5 million in our Accumulation business primarily due to higher fees stemming from an increase in average account values, which resulted from general positive equity market performance in 2011. Partially

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offsetting the increase in net revenue was a $16.6 million decrease in our Guaranteed business primarily due to lower spread earnings and a decline in average account values.

Operating Expenses

        Operating expenses increased $57.2 million in our Accumulation business primarily due to an increase in DPAC amortization expense resulting from mostly level equity markets in 2011, compared to improving equity markets in 2010 and an increase in non-deferrable commission expense and investment management fees resulting from generally positive equity market performance since 2010. Operating expenses decreased $11.9 million in our Guaranteed business primarily resulting from a decrease in DPAC amortization stemming from larger than normal DPAC amortization in 2010 due to an increase in liability call options exercised by us.

Income Taxes

        The effective income tax rates for the segment were 23% and 21% for the years ended December 31, 2011 and 2010, respectively. The effective income tax rates were lower than the U.S. statutory rate primarily as a result of income tax deductions allowed for corporate dividends received and the interest exclusion from taxable income.

Principal Global Investors Segment

Principal Global Investors Trends

        Our overall AUM increased $35.4 billion in 2012 primarily due to continued strong portfolio management as well as positive market performance. We also continue to expand our global presence and experience success in winning institutional asset management mandates and other deposits.

        The following table provides a summary of Principal Global Investor's affiliated and third-party AUM as of the years indicated:

Principal Global Investors Segment Summary Financial Data

        AUM is a key indicator of earnings growth for our Principal Global Investors segment, as AUM is the base by which we generate revenues. Net cash flow and market performance are the two main drivers of AUM growth. Net cash flow reflects our ability to attract and retain client deposits. Market performance reflects equity, fixed income and real estate market performance. The percentage growth in earnings of the segment will generally track with the percentage growth in AUM. This trend may vary due to changes in business and/or product mix.

        The following table presents the AUM rollforward for assets managed by Principal Global Investors for the years indicated:

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        The following table presents certain summary financial data relating to the Principal Global Investors segment for the years indicated:

Year Ended December 31, 2012 Compared to Year Ended December 31, 2011

Operating Earnings

        Operating earnings increased due to higher fee revenue as a result of increased AUM. These increases were partially offset by higher expenses stemming from our focused investment for growth in the areas of global distribution and targeted investment teams.

Income Taxes

        The effective income tax rates for the segment were 32% and 35% for the years ended December 31, 2012 and 2011, respectively. The effective income tax rate was lower than the U.S. statutory rate for the year ended December 31, 2012, primarily due to inclusion of income attributable to noncontrolling interest in pre-tax operating earnings with no corresponding change in income taxes reported by us as the controlling interest.

Year Ended December 31, 2011 Compared to Year Ended December 31, 2010

Operating Earnings

        Operating earnings increased due to higher fee revenues driven by an increase in average AUM. In addition, operating earnings increased due to higher borrower fees from our real estate business resulting from higher transaction volumes and higher servicing fees. These increases were partially offset by higher staff related costs resulting from higher compensation expense, as well as other expenses generally related to our acquisition of Origin in 2011.

Income Taxes

        The effective income tax rate for the segment was 35% for both the years ended December 31, 2011 and 2010.

Principal International Segment

Principal International Trends

        Our Principal International businesses focus on countries with favorable demographics and growing long-term savings and defined contribution markets. With variations depending upon the specific country, we have targeted these markets for sales of retirement and related products and services, including defined contribution pension plans, annuities and mutual funds to businesses and individuals. In some of our international markets, we complement our sales of these products with institutional asset management and life insurance accumulation products.

        We have pursued our international strategy through a combination of start-ups, acquisitions and joint ventures, which require infusions of capital consistent with our strategy of long-term growth and profitability.

Principal International Segment Summary Financial Data

        AUM is a key indicator of earnings growth for the segment, as AUM is the base by which we can generate local currency profits. Net customer cash flow and market performance are the two main drivers of local currency AUM growth. Net customer cash flow reflects our ability to attract and retain client deposits. Market performance reflects the investment returns on our underlying AUM. The percentage growth or decline in the earnings of our Principal International segment will generally track with the percentage growth or decline in AUM. This trend may vary due to changes in business and/or product mix. Our financial results are also impacted by fluctuations of the foreign currency to U.S. dollar exchange rates for the countries in which we have operations. AUM of our foreign subsidiaries is translated

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into U.S. dollar equivalents at the end of the reporting period using the spot foreign exchange rates. Revenue and expenses for our foreign subsidiaries are translated into U.S. dollar equivalents at the average foreign exchange rates.

        The following table presents the Principal International segment AUM rollforward for the years indicated:

        Net revenue is a key metric used to understand the earnings growth for the Principal International segment. Net revenue is defined as operating revenues less benefits, claims and settlement expenses. The following table presents the net revenue of the Principal International segment for the years indicated.

        Net revenue increased primarily due to higher fees driven by higher average AUM in Mexico, higher earnings in our equity method investment in Brazil and the Claritas acquisition in Brazil. These were partially offset by the weakening of the Latin American currencies against the U.S. dollar.

        The following table presents certain summary financial data of the Principal International segment for the years indicated.

Year Ended December 31, 2012 Compared to Year Ended December 31, 2011

Operating Earnings

        Operating earnings increased primarily due to higher fees driven by higher average AUM in Mexico and in our equity method investment in Brazil. These increases were partially offset by the weakening of the Latin American currencies against the U.S. dollar and higher PVFP and DPAC amortization resulting from net unlocking and true-ups in Mexico.

Operating Revenues

        Premiums in Chile increased $20.2 million primarily due to higher sales of single premium annuities with life contingencies, which was partially offset by the weakening of the Chilean peso against the U.S. dollar.

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        Fees and other revenues increased primarily due to higher investment management fees driven by higher average AUM in Mexico and the Claritas acquisition in Brazil, which was partially offset by the weakening of the Latin American currencies against the U.S. dollar.

        Net investment income decreased primarily due to lower inflation-based investment returns on average invested assets and cash as a result of lower inflation in Chile and the weakening of the Latin American currencies against the U.S. dollar. These decreases were partially offset by higher earnings in our equity method investment in Brazil and higher average invested assets in Chile.

Total Expenses

        Benefits, claims and settlement expenses in Chile decreased $14.0 million primarily due to lower inflation-based interest crediting rates to customers and the weakening of the Chilean peso against the U.S. dollar, which were partially offset by an increase in the change in reserves related to higher sales of single premium annuities with life contingencies.

        Operating expenses increased primarily due to higher PVFP and DPAC amortization resulting from net unlocking and true-ups in Mexico coupled with growth initiatives across the segment. These increases were partially offset by the weakening of the Latin American currencies against the U.S. dollar.

Income Taxes

        The effective income tax rates for the segment were 1% and 2% for the years ended December 31, 2012 and 2011, respectively. The effective income tax rates were lower than the U.S. statutory rate primarily due to taxes on our share of earnings generated from our equity method investments. Specifically, our share of earnings generated from equity method investments, net of foreign taxes incurred, are reported within net investment income whereas any residual U.S. tax expense or benefit related to equity method investments is reported in income taxes. Lower tax rates of foreign jurisdictions also contributed to the lower effective income tax rates.

Year Ended December 31, 2011 Compared to Year Ended December 31, 2010

Operating Earnings

        Operating earnings increased primarily due to higher fees driven by higher average AUM as a result of net customer cash flows, market performance and the HSBC AFORE acquisition; the strengthening of the Latin American currencies against the U.S. dollar and higher earnings in our equity method investment in Brazil despite a reduction in the economic interest during the second quarter of 2010.

Operating Revenues

        Premiums in Chile increased $9.6 million primarily due to the strengthening of the Chilean peso against the U.S. dollar, which was partially offset by lower sales of single premium annuities with life contingencies.

        Fees and other revenues increased primarily due to higher investment management fees driven by higher average AUM in Mexico as a result of the HSBC AFORE acquisition.

        Net investment income increased primarily due to higher inflation-based investment returns on average invested assets and cash as a result of higher inflation in Chile, the strengthening of the Latin American currencies against the U.S. dollar and higher earnings in our equity method investment in Brazil despite a reduction in the economic interest during the second quarter of 2010.

Total Expenses

        Benefits, claims and settlement expenses in Chile increased $87.7 million primarily due to higher inflation-based interest crediting rates to customers and the strengthening of the Chilean peso against the U.S. dollar.

        Operating expenses increased primarily due to expenses related to the HSBC AFORE acquisition in Mexico, higher compensation expenses across the segment and the strengthening of the Latin American currencies against the U.S. dollar.

Income Taxes

        The effective income tax rates for the segment were 2% and -1% for the years ended December 31, 2011 and 2010, respectively. The effective income tax rates were lower than the U.S. statutory rate primarily due to taxes on our share of earnings generated from our equity method investments. Specifically, our share of earnings generated from equity method investments, net of foreign taxes incurred, are reported within net investment income whereas any residual U.S. tax expense or benefit related to equity method investments is reported in income taxes. Lower tax rates of foreign jurisdictions also contributed to the lower effective income tax rates.

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U.S. Insurance Solutions Segment

Individual Life Insurance Trends

        Our life insurance premiums and fees are influenced by both economic and industry trends. We have been primarily focused on marketing our universal and variable universal life insurance products. As such, premiums related to our traditional life insurance products have declined for several years. To address recent economic and industry trends, we introduced new term products in 2011. Term life insurance sales increased 58% in 2012.

        The following table provides a summary of our individual universal and variable universal life insurance fee revenues and our individual traditional life insurance premiums for the years indicated:

Specialty Benefits Insurance Trends

        Premium and fees in our specialty benefits insurance business are also influenced by economic and industry trends. Premium and fees have risen more slowly in recent years due to more moderate increases in underlying salaries and lower membership in existing group contracts. We are seeing signs of improvement in both areas.

        The following table provides a summary of our specialty benefits insurance premium and fees for the years indicated:

U.S. Insurance Solutions Segment Summary Financial Data

        There are several key indicators for earnings growth in our U.S. Insurance Solutions segment. The ability of our distribution channels to generate new sales and retain existing business drives growth in our block of business, premium revenue and fee revenues. Our earnings growth also depends on our ability to price our products at a level that enables us to earn a margin over the cost of providing benefits and the expense of acquiring and administering those products. Factors impacting pricing decisions include competitive conditions, economic trends, persistency, our ability to assess and manage trends in mortality and morbidity and our ability to manage operating expenses.

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        The following table presents certain summary financial data relating to the U.S. Insurance Solutions segment for the years indicated:

Year Ended December 31, 2012 Compared to Year Ended December 31, 2011

Operating Earnings

        Operating earnings decreased $60.8 million in our individual life insurance business primarily due to unfavorable unlocking associated with a change in our long-term interest rate assumptions and model refinements in the third quarter of 2012. Operating earnings decreased $5.3 million in our specialty benefits business primarily due to lower yields on invested assets and higher pension and postretirement benefits.

Operating Revenues

        Premiums increased $64.8 million in our specialty benefits insurance business due to growth in all lines of our business and continued recovery in employment and salary trends. Premiums decreased $19.5 million in our individual life insurance business primarily due to an increase in use of ceded premium stemming from growth in our universal life and variable universal life lines of business and, to a lesser extent, expected continued decline from the decreasing block of traditional life insurance business.

        Fees and other revenues increased $3.2 million in our individual life insurance business due to growth in the universal life and variable universal life lines of business and unlocking associated with a change in our long-term interest rate assumptions and model refinements in the third quarter of 2012. The increase was offset by negative unlocking of unearned revenue associated with the change in basis for amortizing DPAC and other actuarial balances in the first quarter of 2012. In addition, fees and other revenues increased $1.7 million in our specialty benefits insurance business primarily due to the acquisition of First Dental Health.

Total Expenses

        Benefits, claims and settlement expenses increased $220.8 million in our individual life insurance business primarily due to the change in amortization basis in the first quarter of 2012, unlocking associated with a change in our long-term interest rate assumptions and model refinements in the third quarter of 2012 and growth in the block of business. In addition, benefits, claims and settlement expenses increased $44.2 million resulting from continued growth in our specialty benefits insurance business.

        Operating expenses decreased $125.1 million in our individual life business primarily due to lower DPAC amortization associated with the change in basis for amortizing DPAC and other actuarial balances in the first quarter of 2012, partially offset by unlocking associated with the change in our long-term interest rate assumptions and model refinements. Operating expenses increased $26.8 million in our specialty benefits insurance business primarily due to growth in the block of business and higher staff related costs, including pension and other postretirement benefits.

Income Taxes

        The effective income tax rates for the segment were 31% and 32% for the years ended December 31, 2012 and 2011, respectively. The effective income tax rates were lower than the U.S. statutory rate as a result of the interest exclusion from taxable income and income tax deductions allowed for corporate dividends received.

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Year Ended December 31, 2011 Compared to Year Ended December 31, 2010

Operating Earnings

        Operating earnings increased due to lowering our long-term interest rate assumptions in 2010 in our individual life insurance business. Growth in specialty benefits also increased operating earnings.

Operating Revenues

        Premiums increased $69.9 million in our specialty benefits insurance business due to strong sales, stabilizing existing case membership and improved lapse rates. Premiums decreased $31.6 million in our individual life insurance business primarily due to the expected continued decline from our decreasing block of traditional life insurance business and the increase use of ceded premium stemming from growth in our universal life and variable universal life lines of business.

        Fees and other revenues increased $58.2 million in our individual life insurance business primarily due to growth in the universal life and variable universal life lines of business.

Total Expenses

        Benefits, claims and settlement expenses increased $50.6 million resulting from continued growth in our specialty benefits insurance business. In addition, benefits, claims and settlement expense increased $23.6 million in our individual life insurance business primarily due to growth in the universal life and variable universal life lines of business.

        Operating expenses increased $39.7 million in our specialty benefits insurance business primarily due to growth. Operating expenses increased $19.5 million in our individual life insurance business due to growth in universal life and variable universal life lines of business.

Income Taxes

        The effective income tax rate for the segment was 32% for both the years ended December 31, 2011 and 2010. The effective income tax rate was lower than the U.S. statutory rate as a result of the interest exclusion from taxable income and income tax deductions allowed for corporate dividends received.

Corporate Segment

Corporate Segment Summary Financial Data

        The following table presents certain summary financial data relating to the Corporate segment for the years indicated:

Year Ended December 31, 2012 Compared to Year Ended December 31, 2011

Operating Loss

        The operating loss decreased due to a reduction in corporate overhead expenses needed to support the exited group medical insurance business. This decrease was partially offset by higher interest expense on corporate debt.

Year Ended December 31, 2011 Compared to Year Ended December 31, 2010

Operating Loss

        The operating loss increased due to a decrease in earnings on average invested assets for the segment, representing capital that has not been allocated to any other segment. This increase was partially offset by a reduction in corporate overhead expenses needed to support the exited group medical insurance business and the 2011 transition of wellness and

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non-medical fee-for-service claim administration businesses, which had operating losses in 2010, from this segment to the U.S. Insurance Solutions segment.

Liquidity and Capital Resources

        Liquidity and capital resources represent the overall strength of a company and its ability to generate strong cash flows, borrow funds at a competitive rate and raise new capital to meet operating and growth needs. Our legal entity structure has an impact on our ability to meet cash flow needs as an organization. Following is a simplified organizational structure.

Liquidity

        Our liquidity requirements have been and will continue to be met by funds from consolidated operations as well as the issuance of commercial paper, common stock, debt or other capital securities and borrowings from credit facilities. We believe that cash flows from these sources are sufficient to satisfy the current liquidity requirements of our operations, including reasonably foreseeable contingencies.

        We maintain a level of cash and securities which, combined with expected cash inflows from investments and operations, is believed to be adequate to meet anticipated short-term and long-term payment obligations. We will continue our prudent capital management practice of regularly exploring options available to us to maximize capital flexibility, including accessing the capital markets and careful attention to and management of expenses.

        Our liquidity is supported by a portfolio of U.S. government and agency and residential pass-through government-backed securities, of which we held $4.3 billion as of December 31, 2012, that may be utilized to bolster our liquidity position, as collateral for secured borrowing transactions with various third parties or by disposing of the securities in the open market, if needed. As of December 31, 2012, approximately $10.9 billion, or 99%, of our institutional guaranteed investment contracts and funding agreements cannot be redeemed by contractholders prior to maturity. Our life insurance and annuity liabilities contain provisions limiting early surrenders.

        As of December 31, 2012 and 2011, we had short-term credit facilities with various financial institutions in an aggregate amount of $905.0 million and $725.0 million, respectively. As of December 31, 2012 and 2011, we had $40.8 million and $105.2 million, respectively, of outstanding borrowings related to our credit facilities, with no assets pledged as support as of December 31, 2012. None of these credit arrangements, other than our commercial paper back-stop facility, are committed facilities. Due to the financial strength and the strong relationships we have with these providers, as well as the small size of these facilities, we are comfortable that there is a very low risk that the financial institutions would not be able to fund these facilities. During the first quarter of 2012, we refinanced our $579.0 million revolving credit agreement that serves as a back-stop to our commercial paper program. The new facility, effective March 30, 2012, was increased to $800.0 million. This facility provides 100% back-stop support for our commercial paper program. The credit agreement is broken into two tranches, a $500.0 million four year facility that matures in March 2016, and a $300 million 364-day facility. The four year facility is set up with PFG, PFS and Principal Life as co-borrowers; the 364-day facility is for Principal Life only. The facility is supported by eighteen banks, most if not all of which have other relationships with us. We have no reason to believe that our current providers would be unable or unwilling to fund the facility if necessary. As of December 31, 2012 and 2011, commercial paper outstanding was $0.0 million and $50.0 million, respectively.

        The Holding Companies: Principal Financial Group, Inc. and Principal Financial Services, Inc.    The principal sources of funds available to our parent holding company, PFG, to meet its obligations, including the payments of dividends on common stock, debt service and the repurchase of stock, are dividends from subsidiaries as well as its ability to borrow funds at competitive rates and raise capital to meet operating and growth needs. Dividends from Principal Life, our primary subsidiary, are limited by Iowa law. Under Iowa laws, Principal Life may pay dividends only from the earned surplus arising from its business and must receive the prior approval of the Insurance Commissioner of the State of Iowa ("the Commissioner") to pay stockholder dividends or make any other distribution if such distributions would exceed certain statutory limitations. Iowa law gives the Commissioner discretion to disapprove requests for distributions in excess

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of these limits. Extraordinary dividends are those, together with dividends or other distributions made within the preceding twelve months, that exceed the greater of (i) 10% of Principal Life's statutory policyholder surplus as of the previous year-end or (ii) the statutory net gain from operations from the previous calendar year. Based on December 31, 2012 statutory results, the dividend limitation for Principal Life is approximately $472.0 million in 2013.

        In 2012, total stockholder dividends paid by Principal Life to its parent were $700.0 million, which were extraordinary and were approved by the Commissioner.

        Based on Iowa law, Principal Life could have distributed approximately $509.7 million in statutory dividends in 2011. Principal Life distributed paid-in and contributed surplus in the amount of $500.0 million to its parent company in 2011. In addition, Principal Life requested and received permission from the Commissioner to pay an extraordinary dividend in the amount of $250.0 million, which was paid by Principal Life to its parent in 2011.

        Based on Iowa law, Principal Life could have distributed approximately $608.7 million in statutory dividends in 2010. No dividends were paid as of December 31, 2010; however, on June 21, 2010, Principal Life distributed paid-in and contributed surplus in the amount of $300.0 million to its parent company.

        Operations.    Our primary consolidated cash flow sources are premiums from insurance products, pension and annuity deposits, asset management fee revenues, administrative services fee revenues, income from investments and proceeds from the sales or maturity of investments. Cash outflows consist primarily of payment of benefits to policyholders and beneficiaries, income and other taxes, current operating expenses, payment of dividends to policyholders, payments in connection with investments acquired, payments made to acquire subsidiaries, payments relating to policy and contract surrenders, withdrawals, policy loans, interest payments and repayment of short-term debt and long-term debt. Our investment strategies are generally intended to provide adequate funds to pay benefits without forced sales of investments. For a discussion of our investment objectives, strategies and a discussion of duration matching, see "Investments" as well as Item 7A. "Quantitative and Qualitative Disclosures About Market Risk — Interest Rate Risk."

        Cash Flows.    Activity, as reported in our consolidated statements of cash flows, provides relevant information regarding our sources and uses of cash. The following discussion of our operating, investing and financing portions of the cash flows excludes cash flows attributable to the separate accounts.

        Net cash provided by operating activities was $3,080.9 million, $2,713.3 million and $2,791.7 for the years ended December 31, 2012, 2011 and 2010, respectively. As an insurance business, we typically generate positive cash flows from operating activities, as premiums collected from our insurance products and income received from our investments exceed policy acquisition costs, benefits paid, redemptions and operating expenses. These positive cash flows are then invested to support the obligations of our insurance products and required capital supporting these products. Our cash flows from operating activities are affected by the timing of premiums, fees, and investment income received and expenses paid. The increase in cash provided by operating activities in 2012 compared to 2011 was the result of an increase in premiums and other consideration received primarily due to an increase in sales of single premium group annuities with life contingencies and a decrease in claims paid. The increase was partially offset by fluctuations in receivables and payables associated with the timing of settlement. The decrease in cash provided by operating activities in 2011 compared to 2010 was the result of a decrease in premiums and other consideration received, partially offset by a decrease in claims, due to our decision to exit the group medical insurance business. The decrease in cash provided by operating activities was also offset by fluctuations in receivables and payables associated with the timing of settlement.

        Net cash used in investing activities was $1,611.4 million and $202.1 million for the years ended December 31, 2012, and 2011, respectively, compared to net cash provided by investing activities of $27.5 million for the year ended December 31, 2010. The increase in cash used in investing activities in 2012 compared to 2011 was due to an increase in net purchases of investments. The increase in cash used in investing activities in 2011 compared to 2010 was primarily due to purchases of interest in subsidiaries in 2011.

        Net cash used in financing activities was $126.2 million, $1,554.7 million and $3,182.2 million for the years ended December 31, 2012, 2011 and 2010, respectively. The decrease in cash used in financing activities was primarily due to the issuance of senior notes in 2012, net of principal repayments, with no corresponding activity in the prior year. Also contributing to the decrease in cash used in financing activities is a decrease in treasury stock repurchased in the current year. The decrease in cash used in financing activities in 2011 compared to 2010 is primarily due to a decrease in net withdrawals of Principal Life general account investment contracts, due to our decision to scale back our investment only business, partially offset by an increase in cash used to repurchase treasury stock in 2011.

        Shelf Registration.    On May 24, 2011, our shelf registration statement was filed with the SEC and became effective. The shelf registration replaces the shelf registration that had been in effect since June 2008. Under our current shelf registration, we have the ability to issue in unlimited amounts, unsecured senior debt securities or subordinated debt securities, junior subordinated debt, preferred stock, common stock, warrants, depository shares, stock purchase contracts and stock purchase units of PFG, trust preferred securities of three subsidiary trusts and guarantees by PFG of these trust preferred securities. Our wholly owned subsidiary, PFS, may guarantee, fully and unconditionally or otherwise, our obligations with respect to any non-convertible securities, other than common stock, described in the shelf

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registration. For information on senior notes issued from our shelf registration, see Item 8. "Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 9, Debt."

        Preferred Stock Dividend Restrictions and Payments.    For preferred stock dividend restriction and payment information, see Item 8. "Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 13, Stockholders' Equity."

        Short-Term Debt and Long-Term Debt.    For debt information, see Item 8. "Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 9, Debt."

        Stockholders' Equity.    Proceeds from the issuance of our common stock were $28.9 million, $25.9 million and $20.6 million in 2012, 2011 and 2010, respectively.

        The following table summarizes our return of capital to common stockholders.

        For additional stockholders' equity information, see Item 8. "Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 13, Stockholders' Equity."

Capitalization

        The following table summarizes our capital structure:

        As of December 31, 2012, we had $270.3 million of excess capital in the holding companies, consisting of cash and highly liquid assets available for debt maturities, interest, preferred stock dividends and other holding company obligations. This is exclusive of the capital that has been earmarked as of December 31 for the Cuprum acquisition consummation. In addition, we continue to maintain sufficient capital levels in Principal Life based on our current financial strength ratings.

Contractual Obligations

        The following table presents payments due by period for long-term contractual obligations as of December 31, 2012.

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Pension and Other Postretirement Plan Funding

        We have defined benefit pension plans covering substantially all of our U.S. employees and certain agents. See Item 8. "Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 11, Employee and Agent Benefits" for a complete discussion of these plans and their effect on the consolidated financial statements.

        We report the net funded status of our pension and other postretirement plans in the consolidated statements of financial position. The net funded status represents the differences between the fair value of plan assets and the projected benefit obligation for pension plans and other postretirement plans. The measurement of the net funded status can vary based upon the fluctuations in the fair value of the plan assets and the actuarial assumptions used for the plans as discussed below. The net underfunded status of the pension and other postretirement benefit obligation was $584.0 million pre-tax and $427.9 million pre-tax as of December 31, 2012 and 2011, respectively. Nonqualified pension plan assets are not included as part of the funding status mentioned above. The nonqualified pension plan assets are held in Rabbi trusts for the benefit of all nonqualified plan participants. The assets held in a Rabbi trust are available to satisfy the claims of general creditors only in the event of bankruptcy. Therefore, these assets are fully consolidated in our consolidated statements of financial position and are not reflected in our funded status as they do not qualify as plan assets under U.S. GAAP. The market value of assets held in these trusts was $300.8 million and $281.2 million as of December 31, 2012 and 2011, respectively.

        Our funding policy for the qualified pension plan is to fund the plan annually in an amount at least equal to the minimum annual contributions required under ERISA and, generally, not greater than the maximum amount that can be deducted for federal income tax purposes. We do not anticipate contributions will be needed to satisfy the minimum funding requirements of ERISA for our qualified pension plan. At this time, it is too early to estimate the amount that may be contributed, but it is possible that we may fund the plans in 2013 in the range of $75 - $125 million. This includes funding for both our qualified and nonqualified pension plans. We may contribute to our other postretirement benefit plans in 2013 pending further analysis.

Contractual Commitments

        In connection with our banking business, we make additional commitments to extend credit, which are agreements to lend to a customer as long as there is no violation of any conditions established in the contract. Commitments generally have fixed expiration dates or other termination clauses and may require payment of a fee. A majority of these commitments are lines of credit and are expected to expire without being drawn upon. Therefore, the total commitment amounts do not necessarily represent future cash funding requirements. We evaluate each customer's creditworthiness on a case-by-case basis. The total commitments to fund loans were $58.7 million as of December 31, 2012.

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        We have made commitments to fund certain limited partnerships in which we are a limited partner. As of December 31, 2012, the amount of unfunded commitments was $30.6 million. We are only required to fund additional equity under these commitments when called upon to do so by the general partner; therefore, these commitments are not liabilities on our consolidated statements of financial position.

Off-Balance Sheet Arrangements

        Variable Interest Entities.    We have relationships with various types of special purpose entities and other entities where we have a variable interest as described in Item 8. "Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 3, Variable Interest Entities." We have made commitments to fund certain limited partnerships, as previously discussed in "Contractual Commitments", some of which are classified as unconsolidated variable interest entities.

        Guarantees and Indemnifications.    As of December 31, 2012, there have been no significant changes to guarantees and indemnifications since December 31, 2011. For guarantee and indemnification information, see Item 8. "Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 12, Contingencies, Guarantees and Indemnifications" under the caption, "Guarantees and Indemnifications."

Financial Strength Rating and Credit Ratings

        Our ratings are influenced by the relative ratings of our peers/competitors as well as many other factors including our operating and financial performance, asset quality, liquidity, asset/liability management, overall portfolio mix, financial leverage (i.e., debt), risk exposures, operating leverage, ratings and other factors.

        A.M. Best Company, Inc., Fitch Rating Ltd., Moody's Investors Service and S&P publish financial strength ratings on U.S. life insurance companies that are indicators of an insurance company's ability to meet contractholder and policyholder obligations. These rating agencies also assign credit ratings on non-life insurance entities, such as PFG and PFS. Credit ratings are indicators of a debt issuer's ability to meet the terms of debt obligations in a timely manner, and are important factors in overall funding profile and ability to access external capital. Such ratings are not a recommendation to buy, sell or hold securities. Ratings are subject to revision or withdrawal at any time by the assigning rating agency.

        A.M. Best, Fitch, and Standard & Poor's maintain a stable outlook on the U.S. life insurance sector, however, Standard & Poor's indicates it is 'cautious' on maintaining the stable outlook. Moody's has changed its outlook to negative. Regardless of their published outlook on the sector, these rating agencies note that current challenges for the industry are the result of sustained low interest rates, global sovereign uncertainty, equity market volatility, and lingering unemployment and fiscal tightening.

        In October, at the time the Cuprum acquisition was announced, A.M. Best affirmed the financial strength ratings of Principal Life and Principal National Life Insurance Company with no change to the stable outlook. S&P and Moody's affirmed the financial strength ratings but changed outlooks to negative. The negative outlooks assigned reflect the pressure from the transaction on certain cash coverage and debt metrics, as well as execution risk. Fitch also affirmed the financial strength ratings of Principal Life and Principal National Life Insurance Company. However, the outlook was changed to rating watch negative, reflecting the execution risk of the pending Cuprum acquisition. On February 12, 2013, after the acquisition was closed, Fitch affirmed the financial strength ratings of Principal Life and Principal National Life Insurance Company and changed the outlook to negative. The negative outlook reflects the pressure of the transaction on certain cash coverage and debt metrics as well as integration risk.

        In its annual review completed in December, A.M. Best affirmed the financial strength ratings of Principal Life and Principal National Life Insurance Company with a stable outlook.

        The following table summarizes our significant financial strength and debt ratings from the major independent rating organizations. The debt ratings shown are indicative ratings. Outstanding issuances are rated the same as indicative ratings unless otherwise noted. Actual ratings can differ from indicative ratings based on contractual terms.

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Impacts of Income Taxes

        For income tax information, see Item 8. "Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 10, Income Taxes."

Fair Value Measurement

        Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (an exit price). The fair value hierarchy prioritizes the inputs to valuation techniques used to measure fair value into three levels for disclosure purposes. The fair value hierarchy gives the highest priority (Level 1) to quoted prices in active markets for identical assets or liabilities and gives the lowest priority (Level 3) to unobservable inputs. An asset or liability's classification within the fair value hierarchy is based on the lowest level of significant input to its valuation. See Item 8. "Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 14, Fair Value Measurements" for further details, including a reconciliation of changes in Level 3 fair value measurements.

        As of December 31, 2012, 41% of our net assets (liabilities) were Level 1, 55% were Level 2 and 4% were Level 3. Excluding separate account assets as of December 31, 2012, 2% of our net assets (liabilities) were Level 1, 97% were Level 2 and 1% were Level 3.

        As of December 31, 2011, 41% of our net assets (liabilities) were Level 1, 55% were Level 2 and 4% were Level 3. Excluding separate account assets as of December 31, 2011, 3% of our net assets (liabilities) were Level 1, 96% were Level 2 and 1% were Level 3.

Changes in Level 3 fair value measurements

        Net assets (liabilities) measured at fair value on a recurring basis using significant unobservable inputs (Level 3) as of December 31, 2012, were $4,987.4 million as compared to $4,647.3 million as of December 31, 2011. The increase was primarily related to gains on other invested assets and real estate included in our separate account assets. This increase was partially offset by sales and net transfers out of Level 3 into Level 2 for certain fixed maturities, available-for-sale. The transfers out of Level 3 were due to our obtaining prices from third party pricing vendors or using internal models based on substantially observable market information versus relying on broker quotes or utilizing significant unobservable inputs.

        Net assets (liabilities) measured at fair value on a recurring basis using significant unobservable inputs (Level 3) as of December 31, 2011, were $4,647.3 million as compared to $4,691.4 million as of December 31, 2010. The slight net decrease was primarily due to net transfers out of Level 3 and into Level 2 offset in part by unrealized gains on real estate separate account assets. The transfers included certain private corporate bonds we are now able to price using a matrix valuation approach as well as certain separate account assets for which we are now able to obtain pricing from a recognized third party pricing vendor.

Investments

        We had total consolidated assets as of December 31, 2012, of $161,926.5 million, of which $68,811.3 million were invested assets. The rest of our total consolidated assets are comprised primarily of separate account assets for which we do not bear investment risk. Because we generally do not bear any investment risk on assets held in separate accounts, the discussion and financial information below does not include such assets.

Overall Composition of Invested Assets

        Invested assets as of December 31, 2012, were predominantly high quality and broadly diversified across asset class, individual credit, industry and geographic location. Asset allocation is determined based on cash flow and the risk/return requirements of our products. As shown in the following table, the major categories of invested assets are fixed maturities

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and commercial mortgage loans. The remainder is invested in other investments, residential mortgage loans, real estate and equity securities. In addition, policy loans are included in our invested assets.

Investment Results

Net Investment Income

        The following table presents the yield and investment income, excluding net realized capital gains and losses, for our invested assets for the periods indicated. We calculate annualized yields using a simple average of asset classes at the beginning and end of the reporting period. The yields for fixed maturities and equity securities are calculated using amortized cost and cost, respectively. All other yields are calculated using carrying amounts.

Year Ended December 31, 2012 Compared to Year Ended December 31, 2011

        Net investment income decreased due to lower reinvestment yields on our invested assets and cash and lower inflation-based investment returns on average invested assets and cash as a result of lower inflation in Chile and the weakening of Latin American currencies against the U.S. dollar. These decreases were partially offset by an increase in average invested assets and cash.

Year Ended December 31, 2011 Compared to Year Ended December 31, 2010

        Net investment income decreased due to lower yields and a decrease in average invested assets and cash primarily due to our decision to scale back our investment only business. These decreases were partially offset by higher inflation-based investment returns on average invested assets, most notably fixed maturities and other investments, as a result of higher inflation in Chile and the strengthening of Latin American currencies against the U.S. dollar. Further offsetting the decline in investment income were gains on sales of development real estate properties.

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Net Realized Capital Gains (Losses)

        The following table presents the contributors to net realized capital gains and losses for our invested assets for the years indicated.

Year Ended December 31, 2012 Compared to Year Ended December 31, 2011

        Net realized capital losses on fixed maturities, available-for-sale — credit impairments decreased primarily due to lower impairments on commercial mortgage-backed and other asset-backed securities as a result of improved market conditions.

        Net realized capital gains on fixed maturities, available-for-sale — other increased as a result of higher gains on sales in 2012 versus 2011.

        Net realized capital losses on derivatives and related hedge activities increased due to increased losses on interest rate swaps and GMWB embedded derivatives, including the spread reflecting our own creditworthiness, and related hedging instruments. These losses were partially offset by gains versus losses on derivatives not designated as hedging instruments, including credit default swaps due to changes in credit spreads and currency forwards and currency swaps due to changes in exchange rates.

        Other net realized capital gains increased in 2012 due to $184.3 million of net gains related to the merger of Catalyst Health Solutions, Inc. and the subsequent disposition of our remaining interest in the merged entity. 2011 included a net realized capital gain of $70.9 million resulting from the sale of a portion of our interest in Catalyst Health Solutions, Inc. Additionally, gains on the sale of real estate and joint ventures in real estate increased in 2012 versus 2011.

Year Ended December 31, 2011 Compared to Year Ended December 31, 2010

        Net realized capital losses on fixed maturities, available-for-sale — credit impairments decreased primarily due to lower impairments on commercial mortgage-backed and other asset-backed securities as a result of improved market conditions.

        Net realized capital losses on fixed maturities, trading increased due to mark-to-market losses versus gains resulting from widening of credit spreads in 2011 and tightening of credit spreads in 2010.

        Net realized capital losses on derivatives and related hedge activities increased due to losses versus gains on derivatives not designated as hedging instruments, including credit default swaps due to changes in credit spreads and currency forwards and currency swaps due to changes in exchange rates.

        Net realized capital losses on commercial mortgages decreased due to a lower valuation allowance provision in 2011 than in 2010. For additional information, see "U.S. Investment Operations — Mortgage Loans — Commercial Mortgage Loan Valuation Allowance."

        Other net realized capital gains increased due to a realized capital gain of $70.9 million in 2011 resulting from the sale of a portion of our interest in Catalyst Health Solutions, Inc., which is accounted for on the equity method, and a $77.6 million decrease in losses related to the residential mortgage loan loss provision for our bank and trust services business. In addition, other net realized capital gains in 2010 included an $80.1 million gain resulting from the signing of our Shareholders Agreement with Banco pertaining to our Brasilprev joint venture.

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U.S. Investment Operations

        Of our invested assets, $62,814.0 million were held by our U.S. operations as of December 31, 2012. Our U.S. invested assets are managed primarily by our Principal Global Investors segment. Our primary investment objective is to maximize after-tax returns consistent with acceptable risk parameters. We seek to protect policyholders' benefits by optimizing the risk/return relationship on an ongoing basis, through asset/liability matching, reducing the credit risk, avoiding high levels of investments that may be redeemed by the issuer, maintaining sufficiently liquid investments and avoiding undue asset concentrations through diversification. We are exposed to two primary sources of investment risk:

•

credit risk, relating to the uncertainty associated with the continued ability of a given obligor to make timely payments of principal and interest and



•

interest rate risk, relating to the market price and/or cash flow variability associated with changes in market yield curves.

        Our ability to manage credit risk is essential to our business and our profitability. We devote considerable resources to the credit analysis of each new investment. We manage credit risk through industry, issuer and asset class diversification. Our Investment Committee, appointed by our Board of Directors, is responsible for establishing all investment policies and approving or authorizing all investments, except the Executive Committee of the Board must approve any investment transaction exceeding $500.0 million. As of December 31, 2012, there are twelve members on the Investment Committee, one of whom is a member of our Board of Directors. The remaining members are senior management members representing various areas of our company.

        We also seek to reduce call or prepayment risk arising from changes in interest rates in individual investments. We limit our exposure to investments that are prepayable without penalty prior to maturity at the option of the issuer and we require additional yield on these investments to compensate for the risk that the issuer will exercise such option. We assess option risk in all investments we make and, when we take that risk, we price for it accordingly.

        Our Fixed Income Securities Committee, consisting of fixed income securities senior management members, approves the credit rating for the fixed maturities we purchase. Teams of security analysts, organized by industry, analyze and monitor these investments. In addition, we have teams who specialize in residential mortgage-backed securities ("RMBS"), commercial mortgage-backed securities ("CMBS"), asset-backed securities ("ABS"), municipals and below investment grade securities. Our analysts monitor issuers held in the portfolio on a continuous basis with a formal review documented annually or more frequently if material events affect the issuer. The analysis includes both fundamental and technical factors. The fundamental analysis encompasses both quantitative and qualitative analysis of the issuer. The qualitative analysis includes an assessment of both accounting and management aggressiveness of the issuer. In addition, technical indicators such as stock price volatility and credit default swap levels are monitored.

        Our Fixed Income Securities Committee also reviews private transactions on a continuous basis to assess the quality ratings of our privately placed investments. We regularly review our investments to determine whether we should re-rate them, employing the following criteria:

•

material changes in the issuer's revenues or margins;



•

significant management or organizational changes;



•

significant changes regarding the issuer's industry;



•

debt service coverage or cash flow ratios that fall below industry-specific thresholds;



•

violation of financial covenants and



•

other business factors that relate to the issuer.

        A dedicated risk management team is responsible for centralized monitoring of the commercial mortgage loan portfolio. We apply a variety of strategies to minimize credit risk in our commercial mortgage loan portfolio. When considering new commercial mortgage loans, we review the cash flow fundamentals of the property, make a physical assessment of the underlying security, conduct a comprehensive market analysis and compare against industry lending practices. We use a proprietary risk rating model to evaluate all new and substantially all existing loans within the portfolio. The proprietary risk model is designed to stress projected cash flows under simulated economic and market downturns. Our lending guidelines are typically 65% or less loan-to-value ratio and a debt service coverage ratio of at least 1.5 times. We analyze investments outside of these guidelines based on cash flow quality, tenancy and other factors. The following table presents loan-to-value and debt service coverage ratios for our brick and mortar commercial mortgages, excluding Principal Global Investors segment mortgages:

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        Our investment decisions and objectives are a function of the underlying risks and product profiles of each primary business operation. In addition, we diversify our product portfolio offerings to include products that contain features that will protect us against fluctuations in interest rates. Those features include adjustable crediting rates, policy surrender charges and market value adjustments on liquidations. For further information on our management of interest rate risk, see Item 7A. "Quantitative and Qualitative Disclosures About Market Risk — Interest Rate Risk."

Overall Composition of U.S. Invested Assets

        As shown in the following table, the major categories of U.S. invested assets are fixed maturities and commercial mortgage loans. The remainder is invested in other investments, real estate, residential mortgage loans and equity securities. In addition, policy loans are included in our invested assets. The following discussion analyzes the composition of U.S. invested assets, but excludes invested assets of the separate accounts.

Fixed Maturities

        Fixed maturities consist of publicly traded and privately placed bonds, asset-backed securities, redeemable preferred stock and certain nonredeemable preferred stock. Included in the privately placed category as of December 31, 2012 and December 31, 2011, were $9.9 billion and $9.1 billion, respectively, of securities subject to certain holding periods and resale restrictions pursuant to Rule 144A of the Securities Act of 1933. Fixed maturities include trading portfolios that support investment strategies that involve the active and frequent purchase and sale of fixed maturities. We held $10.5 million and $279.1 million of these trading securities as of December 31, 2012 and December 31, 2011, respectively.

        Fixed maturities were diversified by category of issuer, as shown in the following table for the periods indicated.

        We believe that it is desirable to hold residential mortgage-backed pass-through securities due to their credit quality and liquidity as well as portfolio diversification characteristics. Our portfolio is comprised of Government National Mortgage Association, Federal National Mortgage Association and Federal Home Loan Mortgage Corporation pass-through securities. In addition, our residential collateralized mortgage obligation portfolio offers structural features that allow cash flows to be matched to our liabilities.

        CMBS provide varying levels of credit protection, diversification and reduced event risk depending on the securities owned and composition of the loan pool. CMBS are predominantly comprised of large pool securitizations that are diverse by property type, borrower and geographic dispersion. The risks to any CMBS deal are determined by the credit quality of the underlying loans and how those loans perform over time. Another key risk is the vintage of the underlying loans and the state of the markets during a particular vintage. In the CMBS market, there is a material difference in the

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outlook for the performance of loans originated in 2005 and earlier relative to loans originated in 2006 through 2008. For loans originated prior to 2006, underwriting assumptions were more conservative regarding required debt service coverage and loan-to-value ratios. For the 2006 through 2008 vintages, real estate values peaked and the underwriting expectations were that values would continue to increase, which makes those loan values more sensitive to market declines. The 2009 through 2012 vintages represent a return to debt service coverage ratios and loan-to-value ratios that more closely resemble loans originated prior to 2006.

        We purchase ABS to diversify the overall credit risks of the fixed maturities portfolio and to provide attractive returns. The principal risks in holding ABS are structural and credit risks. Structural risks include the security's priority in the issuer's capital structure, the adequacy of and ability to realize proceeds from the collateral and the potential for prepayments. Credit risks involve issuer/servicer risk where collateral values can become impaired in the event of servicer credit deterioration. Our ABS portfolio is diversified both by type of asset and by issuer. We actively monitor holdings of ABS to ensure that the risk profile of each security improves or remains consistent. Prepayments in the ABS portfolio are, in general, insensitive to changes in interest rates or are insulated from such changes by call protection features. In the event that we are subject to prepayment risk, we monitor the factors that impact the level of prepayment and prepayment speed for those ABS. In addition, we diversify the risks of ABS by holding a diverse class of securities, which limits our exposure to any one security.

        The international exposure held in our U.S. operation's fixed maturities portfolio was 27% of total fixed maturities as of December 31, 2012, and 26% as of December 31, 2011. It is comprised of corporate and foreign government fixed maturities. The following table presents the carrying amount of our international exposure for our U.S. operation's fixed maturities portfolio for the periods indicated.

        International fixed maturities are determined by the country of domicile of the parent entity of an individual asset. All international fixed maturities held by our U.S. operations are either denominated in U.S. dollars or have been swapped into U.S. dollar equivalents. Our international investments are analyzed internally by country and industry credit investment professionals. We control concentrations using issuer and country level exposure benchmarks, which are based on the credit quality of the issuer and the country. Our investment policy limits total international fixed maturities investments and we are within those internal limits. Exposure to Canada is not included in our international exposure. As of December 31, 2012 and December 31, 2011, our investments in Canada totaled $1,819.0 million and $1,749.1 million, respectively.

        Economic and fiscal conditions in select European countries, including Greece, Ireland, Italy, Portugal and Spain, continue to cause credit concerns particularly to financial institutions and banks with exposure to the European periphery region. Our exposure to the region within our U.S. investment operations fixed maturities portfolio is modest and manageable, representing 2.2% and 2.4% of total fixed maturities as of December 31, 2012 and December 31, 2011, respectively. Additionally, we did not hold any sovereign debt issuances of the selected countries and had not bought or sold credit protection on sovereign issuances as of December 31, 2012 and December 31, 2011.

        The fixed maturities within our U.S. operations portfolio with exposure to the region are primarily corporate credit issuances of large multinational companies where the majority of revenues are coming from outside the country where the parent company is domiciled. Our experience indicates multinational companies have demonstrated better market price performance and credit ratings stability. As of December 31, 2012, 93% of our total portfolio exposure consists of investment grade bonds with an average price of 104 (carrying value/amortized cost) and a weighted average time to maturity of 5 years.

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        The following table presents the carrying amount of our European periphery zone fixed maturities exposure for the periods indicated:

 

        For further details on our International investment operations exposure to these European countries, see "International Investment Operations — Fixed Maturities Exposure."

        Fixed Maturities Credit Concentrations.    One aspect of managing credit risk is through industry, issuer and asset class diversification. Our credit concentrations are managed to established limits. The following table presents our top ten exposures as of December 31, 2012.

        Fixed Maturities Valuation and Credit Quality.    Valuation techniques for the fixed maturities portfolio vary by security type and the availability of market data. The use of different pricing techniques and their assumptions could produce different financial results. See Item 8. "Financial Statements, Notes to Consolidated Financial Statements, Note 14, Fair Value Measurements" for further details regarding our pricing methodology. Once prices are determined, they are reviewed by pricing analysts for reasonableness based on asset class and observable market data. Investment analysts who are familiar with specific securities review prices for reasonableness through direct interaction with external sources, review of recent trade activity or use of internal models. All fixed maturities placed on the "watch list" are periodically analyzed by investment analysts or analysts that focus on troubled securities ("Workout Group"). This group then meets with the Chief Investment Officer and the Portfolio Managers to determine reasonableness of prices. The valuation of impaired bonds for which there is no quoted price is typically based on the present value of the future cash flows expected to be received. Although we believe these values reasonably reflect the fair value of those securities, the key assumptions about risk premiums, performance of underlying collateral (if any) and other market factors involve qualitative and unobservable inputs.

        The Securities Valuation Office ("SVO") of the NAIC monitors the bond investments of insurers for regulatory capital and reporting purposes and, when required, assigns securities to one of six investment categories. For certain bonds, the NAIC designations closely mirror the Nationally Recognized Statistical Rating Organizations' ("NRSRO") credit ratings. For most corporate bonds, NAIC designations 1 and 2 include bonds considered investment grade by such rating organizations. Bonds are considered investment grade when rated "Baa3" or higher by Moody's, or "BBB-" or higher by S&P. NAIC designations 3 through 6 are referred to as below investment grade. Bonds are considered below investment grade when rated "Ba1" or lower by Moody's, or "BB+" or lower by S&P.

        However, for loan-backed and structured securities, as defined by the NAIC, the NAIC rating is not always equivalent to an NRSRO rating as described below. For non-agency RMBS, PIMCO Advisors models and assigns the

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NAIC ratings. For CMBS, Blackrock Solutions undertakes the modeling and assignment of those NAIC ratings. Other loan-backed and structured securities may be subject to an intrinsic price matrix as provided by the NAIC. This may result in a final designation being higher or lower than the NRSRO credit rating.

        The following table presents our total fixed maturities by NAIC designation and the equivalent ratings of the NRSROs as of the periods indicated as well as the percentage, based on fair value, that each designation comprises.

        Fixed maturities include 18 securities with an amortized cost of $232.0 million, gross gains of $7.0 million, gross losses of $0.2 million and a carrying amount of $238.8 million as of December 31, 2012, that are still pending a review and assignment of a rating by the SVO. Due to the timing of when fixed maturities are purchased, legal documents are filed and the review by the SVO is completed, there will always be securities in our portfolio that are unrated over a reporting period. In these instances, an equivalent rating is assigned based on our fixed income analyst's assessment.

        Commercial Mortgage-Backed Securities and Home Equity Asset-Backed Securities Portfolios.    As of December 31, 2012, based on amortized cost, 53% of our CMBS portfolio had ratings of A or higher and 32% was issued in 2005 or before and 6% of our ABS home equity portfolio had ratings of A or higher and 86% was issued in 2005 or before.

        The following tables present our exposure by credit quality, based on the lowest NRSRO designation, and year of issuance ("vintage") for our CMBS portfolio as of the periods indicated.

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(1)

The CMBS portfolio included agency CMBS with a $204.1 million amortized cost and a $210.2 million carrying amount.

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        The following tables present our exposure by credit quality, based on the lowest NRSRO designation, and vintage for our ABS home equity portfolio supported by subprime first lien mortgages as of the periods indicated.

 

        Fixed Maturities Watch List.    We monitor any decline in the credit quality of fixed maturities through the designation of "problem securities," "potential problem securities" and "restructured securities". We define problem securities in our fixed maturity portfolio as securities: (i) as to which principal and/or interest payments are in default or where default is perceived to be imminent in the near term, or (ii) issued by a company that went into bankruptcy subsequent to the acquisition of such securities. We define potential problem securities in our fixed maturity portfolio as securities included on an internal "watch list" for which management has concerns as to the ability of the issuer to comply with the present debt payment terms and which may result in the security becoming a problem or being restructured. The decision whether to classify a performing fixed maturity security as a potential problem involves significant subjective judgments by our management as to the likely future industry conditions and developments with respect to the issuer. We define restructured securities in our fixed maturity portfolio as securities where a concession has been granted to the borrower related to the borrower's financial difficulties that would not have otherwise been considered. We determine that restructures should occur in those instances where greater economic value will be realized under the new terms than through liquidation or other disposition and may involve a change in contractual cash flows. If the present value of the restructured cash flows is less than the current cost of the asset being restructured, a realized capital loss is recorded in net income and a new cost basis is established.

        The following table presents the total carrying amount of our fixed maturities portfolio, as well as its problem, potential problem and restructured fixed maturities for the periods indicated.

        Fixed Maturities Impairments.    We have a process in place to identify securities that could potentially have a credit impairment that is other than temporary. This process involves monitoring market events that could impact issuers' credit ratings, business climate, management changes, litigation and government actions and other similar factors. This process also involves monitoring late payments, pricing levels, downgrades by rating agencies, key financial ratios, financial statements, revenue forecasts and cash flow projections as indicators of credit issues.

        Each reporting period, a group of individuals including the Chief Investment Officer, our Portfolio Managers, members of our Workout Group and representatives from Investment Accounting review all securities to determine

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whether an other-than-temporary decline in value exists and whether losses should be recognized. The analysis focuses on each issuer's ability to service its debts in a timely fashion. Formal documentation of the analysis and our decision is prepared and approved by management.

        We consider relevant facts and circumstances in evaluating whether a credit or interest-rate related impairment of a security is other than temporary. Relevant facts and circumstances considered include: (1) the extent and length of time the fair value has been below cost; (2) the reasons for the decline in value; (3) the financial position and access to capital of the issuer, including the current and future impact of any specific events; (4) for structured securities, the adequacy of the expected cash flows and (5) our intent to sell the security or whether it is more likely than not we will be required to sell the security before recovery of its amortized cost which, in some cases, may extend to maturity. To the extent we determine that a security is deemed to be other than temporarily impaired, an impairment loss is recognized. For additional details, see Item 8. "Financial Statements, Notes to Consolidated Financial Statements, Note 4, Investments."

        We would not consider a security with unrealized losses to be other than temporarily impaired when it is not our intent to sell the security, it is not more likely than not that we would be required to sell the security before recovery of the amortized cost, which may be maturity, and we expect to recover the amortized cost basis. However, we do sell securities under certain circumstances, such as when we have evidence of a change in the issuer's creditworthiness, when we anticipate poor relative future performance of securities, when a change in regulatory requirements modifies what constitutes a permissible investment or the maximum level of investments held or when there is an increase in capital requirements or a change in risk weights of debt securities. Sales generate both gains and losses.

        There are a number of significant risks and uncertainties inherent in the process of monitoring credit impairments and determining if an impairment is other than temporary. These risks and uncertainties include: (1) the risk that our assessment of an issuer's ability to meet all of its contractual obligations will change based on changes in the credit characteristics of that issuer, (2) the risk that the economic outlook will be worse than expected or have more of an impact on the issuer than anticipated, (3) the risk that our investment professionals are making decisions based on fraudulent or misstated information in the financial statements provided by issuers and (4) the risk that new information obtained by us or changes in other facts and circumstances lead us to change our intent to not sell the security prior to recovery of its amortized cost. Any of these situations could result in a charge to net income in a future period.

        The net realized loss relating to other-than-temporary credit impairments and credit related sales of fixed maturities was $118.2 million, $186.7 million and $244.7 million for the years ended December 31, 2012, 2011, and 2010, respectively.

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Fixed Maturities Available-for-Sale

        The following tables present our fixed maturities available-for-sale by industry category and the associated gross unrealized gains and losses, including other-than-temporary impairment losses reported in AOCI, as of the periods indicated.

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        Of the $825.7 million in gross unrealized losses as of December 31, 2012, there were $2.3 million in losses attributed to securities scheduled to mature in one year or less, $20.3 million attributed to securities scheduled to mature between one to five years, $4.1 million attributed to securities scheduled to mature between five to ten years, $251.7 million attributed to securities scheduled to mature after ten years and $547.3 million related to mortgage-backed and other ABS that are not classified by maturity year. As of December 31, 2012, we were in a $2,966.9 million net unrealized gain position as compared to a $1,437.3 million net unrealized gain position as of December 31, 2011. Of the $1,529.6 million increase in net unrealized gains for the year ended December 31, 2012, an approximate $0.2 billion increase can be attributed to an approximate 7 basis points decrease in interest rates in addition to other market factors that increased unrealized gains.

        Fixed Maturities Available-for-Sale Unrealized Losses.    We believe that our long-term fixed maturities portfolio is well diversified among industry types and between publicly traded and privately placed securities. Each year, we direct the majority of our net cash inflows into investment grade fixed maturities. Our current policy is to limit the percentage of cash flow invested in below investment grade assets to 10% of cash flow. During 2012, we did not actively increase our investment in available-for-sale below investment grade assets. While Principal Life's general account investment returns can improve due to the below investment grade asset class, we manage its growth strategically by limiting it to no more than 10% of the total fixed maturities portfolios.

        We invest in privately placed fixed maturities to enhance the overall value of the portfolio, increase diversification and obtain higher yields than are possible with comparable quality public market securities. Generally, private placements provide broader access to management information, strengthened negotiated protective covenants, call protection features and, where applicable, a higher level of collateral. They are, however, generally not freely tradable because of restrictions imposed by federal and state securities laws and illiquid trading markets.

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        The following table presents our fixed maturities available-for-sale by investment grade and below investment grade and the associated gross unrealized gains and losses, including the other-than-temporary impairment losses reported in OCI, as of the periods indicated.

        The following tables present the carrying amount and the gross unrealized losses, including other-than-temporary impairment losses reported in OCI, on investment grade fixed maturities available-for-sale by aging category as of the periods indicated.

 

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        The following tables present the carrying amount and the gross unrealized losses, including other-than-temporary impairment losses reported in OCI, on below investment grade fixed maturities available-for-sale by aging category as of the periods indicated.

 

        The following tables present the carrying amount and the gross unrealized losses, including other-than-temporary impairment losses reported in OCI, on fixed maturities available-for-sale where the estimated fair value had declined and remained below amortized cost by 20% or more as of the periods indicated.

 

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Mortgage Loans

        Mortgage loans consist of commercial mortgage loans on real estate and residential mortgage loans. The carrying amount of our commercial mortgage loan portfolio was $10,167.7 million and $9,386.0 million as of December 31, 2012 and December 31, 2011, respectively. The carrying amount of our residential mortgage loan portfolio was $657.7 million and $746.0 million as of December 31, 2012 and December 31, 2011, respectively.

        Commercial Mortgage Loans.    We generally report commercial mortgage loans on real estate at cost adjusted for amortization of premiums and accrual of discounts, computed using the interest method and net of valuation allowances.

        Commercial mortgage loans play an important role in our investment strategy by:

•

providing strong risk-adjusted relative value in comparison to other investment alternatives;



•

enhancing total returns and



•

providing strategic portfolio diversification.

        As a result, we have focused on constructing a solid, high quality portfolio of mortgages. Our portfolio is generally comprised of mortgages originated with conservative loan-to-value ratios, high debt service coverages and general purpose property types with a strong credit tenancy.

        Our commercial mortgage loan portfolio consists primarily of non-recourse, fixed rate mortgages on fully or near fully leased properties. The mortgage portfolio is comprised primarily of credit oriented retail properties, office properties, general-purpose industrial properties and apartments.

        Our commercial mortgage loan portfolio is diversified by geography and specific collateral property type. Commercial mortgage lending in the state of California accounted for 20% and 22% of our commercial mortgage loan portfolio as of December 31, 2012 and December 31, 2011, respectively. We are, therefore, exposed to potential losses resulting from the risk of catastrophes, such as earthquakes, that may affect the region. Like other lenders, we generally do not require earthquake insurance for properties on which we make commercial mortgage loans. With respect to California properties, however, we obtain an engineering report specific to each property. The report assesses the building's design specifications, whether it has been upgraded to meet seismic building codes and the maximum loss that is likely to result from a variety of different seismic events. We also obtain a report that assesses, by building and geographic fault lines, the amount of loss our commercial mortgage loan portfolio might suffer under a variety of seismic events.

        The typical borrower in our commercial loan portfolio is a single purpose entity or single asset entity. As of December 31, 2012 and December 31, 2011, the total number of commercial mortgage loans outstanding was 977 and 975, of which 68% and 71% were for loans with principal balances less than $10 million, respectively. The average loan size of our commercial mortgage portfolio was $10.4 million and $9.7 million as of December 31, 2012 and December 31, 2011, respectively.

        Commercial Mortgage Loan Credit Monitoring.    For further details on monitoring and management of our commercial mortgage loan portfolio, see Item 8. "Financial Statements, Notes to Consolidated Financial Statements, Note 4, Investments — Mortgage Loan Credit Monitoring."

        We categorize loans that are 60 days or more delinquent, loans in process of foreclosure and loans with borrowers or credit tenants in bankruptcy that are delinquent as "problem" loans. Valuation allowances or charge-offs have been recognized on most problem loans. We categorize loans that are delinquent less than 60 days where the default is expected to be cured and loans with borrowers or credit tenants in bankruptcy that are current as "potential problem" loans. The decision whether to classify a loan delinquent less than 60 days as a potential problem involves significant subjective judgments by management as to the likely future economic conditions and developments with respect to the borrower. We categorize loans for which the original note rate has been reduced below market and loans for which the principal has been reduced as "restructured" loans. We also consider loans that are refinanced more than one year beyond the original maturity or call date at below market rates as restructured.

        There has been a decrease in the total level of problem, potential problem and restructured commercial mortgages during 2012 primarily due to loan payoffs, foreclosures, and improvement in collateral occupancies and values. The South Atlantic and East North Central regions accounted for over 80% of the problem, potential problem and restructured commercial mortgages as of December 31, 2012. The South Atlantic, Pacific, and East North Central regions accounted for over 90% of the problem, potential problem, and restructured commercial mortgages as of December 31, 2011. Office properties accounted for over half of the problem, potential problem and restructured commercial mortgages as of December 31, 2012. Office and apartment properties accounted for over half of the problem, potential problem and restructured commercial mortgages as of December 31, 2011.

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        The following table presents the carrying amounts of problem, potential problem and restructured commercial mortgages relative to the carrying amount of all commercial mortgages for the periods indicated.

        Commercial Mortgage Loan Valuation Allowance.    The valuation allowance for commercial mortgage loans includes loan specific reserves for loans that are deemed to be impaired as well as reserves for pools of loans with similar characteristics where a property risk or market specific risk has not been identified but for which we anticipate a loss may occur. For further details on the commercial mortgage valuation allowance, see Item 8. "Financial Statements, Notes to Consolidated Financial Statements, Note 4, Investments — Mortgage Loan Valuation Allowance."

        The valuation allowance decreased $13.0 million for the year ended December 31, 2012, and decreased $15.8 million for the year ended December 31, 2011. The decrease in the level of valuation allowance during 2012 and 2011 was related to the same market factors as those causing the decrease in the level of problem, potential problem and restructured commercial mortgages during the year ended December 31, 2012. The South Atlantic region accounts for the highest level of reserves at both December 31, 2012 and December 31, 2011.

        The following table represents our commercial mortgage valuation allowance for the periods indicated.

        Residential Mortgage Loans.    The residential mortgage loan portfolio is composed of home equity mortgages with an amortized cost of $495.7 million and $611.0 million and first lien mortgages with an amortized cost of $206.4 million and $171.0 million as of December 31, 2012 and December 31, 2011, respectively, primarily held by our Bank and Trust Services business. The home equity loans are generally second lien mortgages made up of closed-end loans and lines of credit. Non-performing residential mortgage loans, which are defined as loans 90 days or greater delinquent plus non-accrual loans, totaled $32.3 million and $24.0 million as of December 31, 2012 and December 31, 2011, respectively.

        We establish the residential mortgage loan valuation allowance at levels considered adequate to absorb probable losses within the portfolio based on management's evaluation of the size and current risk characteristics of the portfolio. Such evaluation considers numerous factors, including, but not limited to net charge-off trends, loss forecasts, collateral values, geographic location, borrower credit scores, delinquency rates, industry condition and economic trends. During the third quarter of 2012, we increased our provision and charge-offs primarily due to implementation of guidance provided by the Office of the Comptroller of the Currency ("OCC") Bank Accounting Advisory Series, which provided additional clarification on accounting for loans discharged in bankruptcy and measurement of impairment on certain restructured loans. As of December 31, 2012, only 4% of loans that were charged off under the OCC guidance were 30 days or more past due. Implementation of this guidance also increased our nonaccrual loans. The changes in the valuation allowance are reported in net realized capital gains (losses) on our consolidated statements of operations.

        Our residential mortgage loan portfolio, and in particular our home equity loan portfolio, experienced an increase in loss severity from sustained elevated levels of unemployment along with continued depressed collateral values beginning in 2010. While these factors continue to drive charge-offs, loss rates overall have stabilized and the portfolio balance

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continues to decline. The following table represents our residential mortgage valuation allowance for the periods indicated.

Real Estate

        Real estate consists primarily of commercial equity real estate. As of December 31, 2012 and December 31, 2011, the carrying amount of our equity real estate investment was $1,172.5 million, or 2%, and $1,083.9 million, or 2%, of U.S. invested assets, respectively. Our commercial equity real estate is held in the form of wholly owned real estate, real estate acquired upon foreclosure of commercial mortgage loans and majority owned interests in real estate joint ventures.

        Equity real estate is categorized as either "real estate held for investment" or "real estate held for sale." Real estate held for investment totaled $1,092.5 million and $1,047.3 million as of December 31, 2012 and December 31, 2011, respectively. The carrying value of real estate held for investment is generally adjusted for impairment whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable. Such impairment adjustments are recorded as net realized losses and, accordingly, are reflected in our consolidated results of operations. For the year ended December 31, 2012 and 2011, there were no such impairment adjustments.

        The carrying amount of real estate held for sale was $80.0 million and $36.6 million as of December 31, 2012 and December 31, 2011, respectively. There were no valuation allowances as of December 31, 2012 or December 31, 2011. Once we identify a real estate property to be sold and commence a plan for marketing the property, we classify the property as held for sale. We establish a valuation allowance subject to periodic revisions, if necessary, to adjust the carrying value of the property to reflect the lower of its current carrying value or the fair value, less associated selling costs.

        We use research, both internal and external, to recommend appropriate product and geographic allocations and changes to the equity real estate portfolio. We monitor product, geographic and industry diversification separately and together to determine the most appropriate mix.

        Equity real estate is distributed across geographic regions of the country with larger concentrations in the South Atlantic, Pacific, and West South Central regions of the United States as of December 31, 2012. By property type, there is a concentration in office, retail, and industrial that represented approximately 75% of the equity real estate portfolio as of December 31, 2012.

Other Investments

        Our other investments totaled $1,847.4 million as of December 31, 2012, compared to $1,783.5 million as of December 31, 2011. Derivative assets accounted for $996.0 million and $1,156.5 million in other investments as of December 31, 2012 and December 31, 2011, respectively. The remaining invested assets include equity method investments, which include real estate properties owned jointly with venture partners and operated by the partners.

International Investment Operations

        Of our invested assets, $5,997.3 million were held by our Principal International segment as of December 31, 2012. The assets are managed by either our Principal Global Investors segment or by the local Principal International affiliate. Due to the regulatory constraints in each country, each company maintains its own investment policies. As shown in the following table, the major categories of international invested assets as of December 31, 2012 and December 31, 2011, were fixed maturities, other investments and residential mortgage loans. The remainder is invested in equity securities,

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commercial mortgage loans and real estate. In addition, policy loans are included in our invested assets. The following table excludes invested assets of the separate accounts.

        Investments in equity method subsidiaries and direct financing leases accounted for $718.0 million and $655.1 million, respectively, of other investments as of December 31, 2012, and $667.5 million and $507.5 million, respectively, of other investments as of December 31, 2011. The remaining other investments as of both December 31, 2012 and December 31, 2011, are primarily related to derivative assets and other short-term investments.

Fixed Maturities Exposure

        Economic and fiscal conditions in select European countries, including Greece, Ireland, Italy, Portugal and Spain, continue to cause credit concerns particularly to financial institutions and banks with exposure to the European periphery region. Our exposure to the region within our International investment operations fixed maturities portfolio is manageable, representing 6.2% and 7.8% of our total International invested assets as of December 31, 2012 and December 31, 2011, respectively. Portfolio holdings with exposure to this region consist of fixed maturities issued in the same countries as our International operations by local subsidiaries of the European parent. Nearly all of the exposure is to bonds issued in Chile. In addition, we did not hold any sovereign debt issuances of the selected countries and had not bought or sold credit protection on sovereign issuances as of December 31, 2012 and December 31, 2011.

        Financial sector exposure is to local subsidiary banks, subject to local capital requirements and banking regulation. The current financial exposure carries an average AA local rating from S&P and the average time to maturity is 18 years. Non-financial sector exposure consists primarily of infrastructure bonds, which are backed by the project itself, often with minimum revenue guarantees from the government. The current non-financial exposure carries an average AA local rating from S&P. The current Italian exposure has an average time to maturity of 12 years. In addition, the current Spanish exposure has an average time to maturity of 14 years. As of December 31, 2012, our total portfolio exposure had an average price of 107 (carrying value/amortized cost).

        The following table presents the carrying amount of our European periphery zone fixed maturities exposure for the periods indicated.

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        For further details on our U.S. investment operations exposure to these European countries, see "U.S. Investment Operations — Fixed Maturities."

Item 7A.    Quantitative and Qualitative Disclosures About Market Risk

Market Risk Exposures and Risk Management

        Market risk is the risk we will incur losses due to adverse fluctuations in market rates and prices. Our primary market risk exposure is to changes in interest rates, although we also have exposures to changes in equity prices and foreign currency exchange rates.

        We enter into market-sensitive instruments primarily for purposes other than trading. The active management of market risk is an integral part of our operations. We manage our overall market risk exposure within established risk tolerance ranges by using the following approaches:

•

rebalance our existing asset or liability portfolios;



•

control the risk structure of newly acquired assets and liabilities or



•

use derivative instruments to modify the market risk characteristics of existing assets or liabilities or assets expected to be purchased.

Interest Rate Risk

        Interest rate risk is the risk we will incur economic losses due to adverse changes in interest rates. We are exposed to interest rate risk from several sources:

•

Due to the inherent difficulty in obtaining assets that mature or have their rate reset at the exact same time as the liabilities they support, assets may have to be reinvested or sold in the future to meet the liability cash flows in unknown interest rate environments.



•

There may be timing differences between when new liabilities are priced and when assets are purchased or procured that can cause fluctuations in profitability if interest rates move materially in the interim.



•

Prepayment options embedded within asset and liability contracts can alter the cash flow profiles from what was originally expected.



•

The spreads between the investment income we earn and the interest we credit to customers who own products with guaranteed minimum interest rates may decrease (or potentially become negative) during periods of sustained low interest rates.



•

During periods of sustained low interest rates, the interest rates that we earn on our assets may be lower than the rates assumed in pricing our insurance products, thereby reducing our profitability. If interest rates remain low over a sustained period of time, this may result in increases in our reserves and unlocking of our DPAC asset and other actuarial balances.



•

During a period of rising interest rates, policy surrenders, withdrawals, and requests for policy loans may increase as customers seek to achieve higher returns. We may be required to sell assets to raise the cash necessary to respond to such surrenders, withdrawals and loans, thereby realizing capital losses on the assets sold.



•

For our long-term borrowings, we are exposed to interest rate risk at the time of maturity or early redemption, when we may be required to refinance our obligations.



•

We are exposed to interest rate risk based upon the discount rate assumption used for purposes of valuing our pension and other postretirement benefit obligations.

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        The following table provides detail on the differences between the interest rates being credited to contractholders as of December 31, 2012, and the respective guaranteed minimum interest rates, broken down by account values within the Retirement and Investor Services, U.S. Insurance Solutions and Principal International segments.

        One of the measures we use to quantify our exposure to interest rate risk is duration. To calculate duration, we project asset and liability cash flows. These cash flows are discounted to a net present value basis using a spot yield curve, which is a blend of the spot yield curves for each of the asset types in the portfolio. Duration is calculated by re-calculating these cash flows, re-determining the net present value based upon an alternative level of interest rates, and determining the percentage change in fair value.

        We manage interest rate risks in a number of ways. Differences in durations between assets and liabilities are measured and kept within acceptable tolerances. Derivatives are also commonly used to mitigate interest rate risk due to cash flow mismatches and timing differences. Prepayment risk is controlled by limiting our exposure to investments that are prepayable without penalty prior to maturity at the option of the issuer. We also require additional yield on these investments to compensate for the risk the issuer will exercise such option. Prepayment risk is also controlled by limiting the sales of liabilities with features such as puts or other options that can be exercised against the company at inopportune times. For example, as of December 31, 2012, approximately $10.9 billion, or 99%, of our institutional GICs and funding agreements cannot be redeemed by contractholders prior to maturity. We manage the interest rate risk associated with our long-term borrowings by monitoring the interest rate environment and evaluating refinancing opportunities as maturity dates approach.

        In 2012, plan fiduciaries implemented a Dynamic Asset Allocation strategy for our qualified defined benefit pension plan which strategically allocates an increasing portion of the assets of the pension plan to fixed income securities as the GAAP funding status improves. The intended purpose of using the Dynamic Asset Allocation strategy is that the expected change in the value of the plan assets and the change in pension benefit obligation due to market movements are more likely to have more correlation versus a static allocation of assets between categories. See Item 7. "Management's Discussion and Analysis of Financial Condition and Results of Operations — Critical Accounting Policies and Estimates — Benefit Plans" and Item 8. "Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 11, Employee and Agent Benefits" for more information.

        Duration-Managed.    Our exposure to interest rate risk stems largely from our substantial holdings of guaranteed fixed rate liabilities in our Retirement and Investor Services segment. We actively manage the duration of assets and liabilities in these products by minimizing the difference between the two.

        As of December 31, 2012, the difference between the asset and liability durations on our primary duration-managed portfolio was -0.13, as compared to -0.35 as of December 31, 2011. This duration gap indicates that, as of December 31, 2012, the sensitivity of the fair value of our assets to interest rate movements is less than that of the fair value of our liabilities. Our goal is to minimize the duration gap. Currently, our guidelines indicate that total duration

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gaps between the asset and liability portfolios should be within +/-0.25. The value of the assets in this portfolio was $27,903.0 million and $26,811.6 million as of December 31, 2012 and December 31, 2011, respectively.

        Duration-Monitored.    For products such as whole life insurance and term life insurance that are less sensitive to interest rate risk, and for other products such as individual fixed deferred annuities, we manage interest rate risk based on a modeling process that considers the target average life, maturities, crediting rates and assumptions of policyholder behavior. As of December 31, 2012, the estimated weighted-average difference between the asset and liability durations on these portfolios was -3.07, as compared to -3.03 as of December 31, 2011. This duration gap indicates that, as of December 31, 2012, the sensitivity of the fair value of our assets to interest rate movements is less than that of the fair value of our liabilities. We attempt to monitor this duration gap consistent with our overall risk/reward tolerances. The value of the assets in these portfolios was $26,446.4 million and $25,650.8 million as of December 31, 2012 and December 31, 2011, respectively.

        Non Duration-Managed.    We also have a block of participating general account pension business that passes most of the actual investment performance of the assets to the customer. The investment strategy of this block is to maximize investment return to the customer on a "best efforts" basis, and there is little or no attempt to manage the duration of this portfolio since there is little or no interest rate risk. The value of the assets in these portfolios was $4,935.8 million and $5,400.0 million as of December 31, 2012 and December 31, 2011, respectively.

        Using the assumptions and data in effect as of December 31, 2012, we estimate that a 100 basis point immediate, parallel increase in interest rates increases the net fair value of our portfolio by approximately $847.8 million, compared with an estimated $871.9 million increase as of December 31, 2011. The following table details the estimated changes by risk management strategy. The table also gives the weighted-average duration of the asset portfolio for each category, and the net duration gap (i.e., the weighted-average difference between the asset and liability durations).

        Our selection of a 100 basis point immediate, parallel increase or decrease in interest rates is a hypothetical rate scenario we use to demonstrate potential risk. While a 100 basis point immediate, parallel increase does not represent our view of future market changes, it is a near term reasonably possible hypothetical change that illustrates the potential impact of such events. While these fair value measurements provide a representation of interest rate sensitivity, they are based on our portfolio exposures at a point in time and may not be representative of future market results. These exposures will change as a result of ongoing portfolio transactions in response to new business, management's assessment of changing market conditions and available investment opportunities.

        See Item 7. "Management's Discussion and Analysis of Financial Condition and Results of Operations — Critical Accounting Policies and Estimates — Valuation and Impairment of Fixed Income Investments" for additional discussion of the impact interest rate increases would have on fixed maturities, available-for-sale.

        Debt Issued and Outstanding.    The aggregate fair value of long-term debt, excluding accrued interest, was $2,951.4 million and $1,750.7 million, as of December 31, 2012 and December 31, 2011, respectively. As of December 31, 2012, we estimate that a 100 basis point immediate, parallel decrease in interest rates would increase the fair value of debt by approximately $308.1 million, as compared to an estimated $129.1 million increase as of December 31, 2011. As of December 31, 2012, we estimate that a 100 basis point immediate, parallel increase in interest rates would decrease the fair value of debt by approximately $289.3 million, as compared to an estimated $118.1 million decrease as of December 31, 2011. Debt is not recorded at fair value on the consolidated statements of financial position.

        Our selection of a 100 basis point immediate, parallel increase or decrease in interest rates is a hypothetical rate scenario we use to demonstrate potential risk. While a 100 basis point immediate, parallel increase or decrease does not represent our view of future market changes, it is a near term reasonably possible hypothetical change that illustrates the potential impact of such events. While these fair value measurements provide a representation of interest rate sensitivity, they are based on our long-term debt obligations at a point in time and may not be representative of future obligations. These exposures will change as a result of ongoing changes to our outstanding long-term debt obligations.

        For additional information regarding our debt, see Item 8. "Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 9, Debt."

        Use of Derivatives to Manage Interest Rate Risk.    We use or have previously used various derivative financial instruments to manage our exposure to fluctuations in interest rates, including interest rate swaps, interest rate collars, swaptions and futures. We use interest rate swaps and futures contracts to hedge changes in interest rates subsequent to the issuance of an insurance liability, such as a guaranteed investment contract, but prior to the purchase of a supporting

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asset, or during periods of holding assets in anticipation of near term liability sales. We use interest rate swaps primarily to more closely match the interest rate characteristics of assets and liabilities. They can be used to change the sensitivity to the interest rate of specific assets and liabilities as well as an entire portfolio. We use interest rate collars to manage interest rate risk related to guaranteed minimum interest rate liabilities in our individual annuities contracts. We purchase swaptions to offset existing exposures.

        Derivatives in our portfolio with interest rate sensitivity were in a net liability position with a fair value of $247.0 million and $424.6 million as of December 31, 2012 and December 31, 2011, respectively. The following table shows the interest rate sensitivity of our derivatives measured in terms of fair value. These exposures will change as a result of ongoing portfolio and risk management activities.

        Our selection of a 100 basis point immediate, parallel increase or decrease in interest rates is a hypothetical rate scenario we use to determine potential risk. While a 100 basis point immediate, parallel increase or decrease does not represent our view of future market changes, it is a near term reasonably possible hypothetical change that illustrates the potential impact of such events. While these fair value measurements provide a representation of interest rate sensitivity, they are based on our derivative portfolio exposures at a point in time and may not be representative of future market results. These exposures will change as a result of ongoing derivative transactions.

Foreign Currency Risk

        Foreign currency risk is the risk we will incur economic losses due to adverse fluctuations in foreign currency exchange rates. This risk arises from foreign currency-denominated funding agreements issued to nonqualified institutional investors in the international market, foreign currency-denominated fixed maturities and our international operations, including potential acquisition and divestiture activity.

        We estimate that as of December 31, 2012, a 10% immediate unfavorable change in each of the foreign currency exchange rates to which we are exposed would result in no material change to the net fair value of our foreign currency denominated instruments identified above because we effectively hedge foreign currency denominated instruments to minimize exchange rate impacts, which is consistent with our estimate as of December 31, 2011. However, fluctuations in foreign currency exchange rates do affect the translation of operating earnings and equity of our international operations into our consolidated financial statements.

        For our Principal International segment, we estimate that a 10% immediate unfavorable change in each of the foreign currency exchange rates to which we were exposed would have resulted in a $191.2 million, or 10%, reduction in the total equity excluding noncontrolling interests of our international operations as of December 31, 2012, as compared to an estimated $167.8 million, or 10%, reduction as of December 31, 2011. We estimate that a 10% unfavorable change in the average foreign currency exchange rates to which we were exposed through our international operations would have resulted in a $17.5 million, or 11%, reduction in the operating earnings of our international operations for the year ended December 31, 2012, as compared to an estimated $14.8 million, or 10%, reduction for the year ended December 31, 2011.

        The selection of a 10% immediate unfavorable change in all currency exchange rates should not be construed as a prediction by us of future market events, but rather as an illustration of the potential impact of such an event. These exposures will change as a result of a change in the size and mix of our foreign operations.

        Use of Derivatives to Manage Foreign Currency Risk.    The foreign currency risk on funding agreements and fixed maturities is mitigated by using currency swaps that swap the foreign currency interest and principal payments to our functional currency. The notional amount of our currency swap agreements associated with foreign-denominated liabilities was $2,209.6 million and $2,454.3 million as of December 31, 2012 and December 31, 2011, respectively. The notional amount of our currency swap agreements associated with foreign-denominated fixed maturities was $1,164.0 million and $1,390.1 million as of December 31, 2012 and December 31, 2011, respectively.

        With regard to our international operations, in order to enhance the diversification of our investment portfolios we may invest in bonds denominated in a currency that is different than the currency of our liabilities. We use foreign exchange derivatives to economically hedge the currency mismatch. Our operations in Chile had currency swaps with a

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notional amount of $80.5 million and $75.4 million as of December 31, 2012 and December 31, 2011, respectively. Chile also utilized currency forwards with a notional amount of $257.2 million and $147.3 million as of December 31, 2012 and December 31, 2011, respectively.

        We used currency options with a notional amount of $1,400.0 million and currency forwards with a notional amount of $300.0 million as of December 31, 2012, to manage the foreign currency risk associated with a business combination. There were no hedges of business combinations outstanding at December 31, 2011. Additionally, from time to time we take measures to hedge our net equity investments in our foreign subsidiaries from currency risks. There were no outstanding net equity investment hedges in 2012 or 2011.

Equity Risk

        Equity risk is the risk we will incur economic losses due to adverse fluctuations in common stock prices. As of December 31, 2012 and December 31, 2011, the fair value of our equity securities was $389.3 million and $481.9 million, respectively. As of December 31, 2012, we estimate that a 10% decline in the value of the equity securities would result in an unrealized loss of $38.9 million, as compared to an estimated unrealized loss of $48.2 million as of December 31, 2011.

        We are also exposed to the risk that asset-based fees decrease as a result of declines in assets under management due to changes in investment prices and the risk that asset management fees calculated by reference to performance could be lower. The risk of decreased asset-based and asset management fees could also impact our estimates of total gross profits used as a basis for amortizing deferred policy acquisition costs and other actuarial balances. We estimate that an immediate 10% decline in the S&P index, followed by a 2% per quarter increase would reduce our annual operating earnings by approximately 4% to 6%. The risk of decreased asset-based and asset management fees could also impact our estimates of total gross profits used as a basis for amortizing deferred policy acquisition costs and other actuarial balances. For further discussion, see Item 7. "Management's Discussion and Analysis of Financial Condition and Results of Operations — Critical Accounting Policies and Estimates — Deferred Policy Acquisition Costs and Other Actuarial Balances."

        The selection of a 10% unfavorable change in the equity markets should not be construed as a prediction by us of future market events, but rather as an illustration of the potential impact of such an event. Our exposure will change as a result of changes in our mix of business.

        We also have equity risk associated with (1) fixed deferred annuity contracts that credit interest to customers based on changes in an external equity index; (2) variable annuity contracts that have a GMWB rider that allows the customer to make withdrawals of a specified annual amount, either for a fixed number of years or for the lifetime of the customer, even if the account value is reduced to zero; (3) variable annuity contracts that have a guaranteed minimum death benefit ("GMDB") that allows the death benefit to be paid, even if the account value has fallen below the GMDB amount; (4) investment-type contracts in which the return is tied to an external equity index and (5) investment-type contracts in which the return is subject to minimum contractual guarantees. We are also subject to equity risk based upon the assets that support our employee benefit plans. For further discussion of equity risk associated with these plans, see Item 7. "Management's Discussion and Analysis of Financial Condition and Results of Operations — Critical Accounting Policies and Estimates — Benefit Plans."

        Use of Derivatives to Manage Equity Risk.    We economically hedge the fixed deferred annuity product, where the interest credited is linked to an external equity index, by purchasing options that match the product's profile. We economically hedge the GMWB exposure, which includes interest rate risk and equity risk, using futures, options and interest rate swaps. We economically hedge the investment contract exposure to an external equity index using equity call options. The fair value of both the GMWB embedded derivative and associated hedging instruments are sensitive to financial market conditions and the variance related to the change in fair value of these items for a given period is largely dependent on market conditions at the end of the period. We economically hedge these exposures, which includes interest rate risk and equity risk, using futures, options and interest rate swaps with notional amounts of $455.6 million, $1,811.8 million, and $2,904.8 million, respectively.

Credit Risk

        Credit risk relates to the uncertainty associated with the continued ability of a given obligor to make timely payments of principal and interest. Our ability to manage credit risk is essential to our business and our profitability. See Item 7. "Management's Discussion and Analysis of Financial Condition and Results of Operations — Investments" for additional information about credit risk.

        Use of Derivatives to Diversify or Hedge Credit Risk.    We purchase credit default swaps to hedge credit exposures in our investment portfolio and total return swaps to hedge our investment portfolio from credit losses. We sell credit default swaps to offer credit protection to investors when entering into synthetic replicating transactions. When selling credit protection, if there is an event of default by the referenced name, we are obligated to pay the counterparty the referenced amount of the contract and receive in return the referenced security. For further information on credit derivatives sold, see Item 8. "Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 5, Derivative Financial Instruments" under the caption, "Credit Derivatives Sold."

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        We economically hedged credit exposure in our portfolio by purchasing credit default swaps with a notional amount of $359.8 million and $607.0 million and total return swaps of $100.0 million and $15.0 million as of December 31, 2012 and December 31, 2011, respectively. We had credit exposure through credit default swaps with a notional amount of $110.4 million and $147.4 million as of December 31, 2012 and December 31, 2011, respectively, by investing in various tranches of synthetic collateralized debt obligations. In addition, we sold credit default swaps creating replicated assets with a notional amount of $908.1 million and $775.9 million as of December 31, 2012 and December 31, 2011, respectively.

Derivative Counterparty Risk

        In conjunction with our use of derivatives, we are exposed to counterparty risk, or the risk that the counterparty fails to perform the terms of the derivative contract. We actively manage this risk by:

•

obtaining approval of all new counterparties by the Investment Committee;



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establishing exposure limits that take into account non-derivative exposure we have with the counterparty as well as derivative exposure;



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performing similar credit analysis prior to approval on each derivatives counterparty that we do when lending money on a long-term basis;



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diversifying our risk across numerous approved counterparties;



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implementing credit support annex (collateral) agreements ("CSAs") with a majority of our counterparties to further limit counterparty exposures, which provide for netting of exposures;



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limiting exposure to A credit or better for counterparties without CSAs;



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conducting stress-test analysis to determine the maximum exposure created during the life of a prospective transaction and



•

daily monitoring of counterparty credit ratings, exposures and associated collateral levels.

        We believe the risk of incurring losses due to nonperformance by our counterparties is manageable. For further information on derivatives, see Item 8. "Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 5, Derivative Financial Instruments."

        Based on our accounting policy, our disclosed exposure measures the fair value of derivatives that have become favorable to us and, therefore, is a combined credit exposure if all of the involved counterparties failed to fulfill their obligations. In the hypothetical scenario where all of our counterparties fail to fulfill their obligations, our exposure would be $1,086.7 million; however, including collateral received our exposure would be reduced to $838.7 million at December 31, 2012. For further information on derivative exposure, see Item 8. "Financial Statements and Supplementary Data, Notes to Consolidated Financial Statements, Note 5, Derivative Financial Instruments" under the caption, "Exposure."

        We manage our exposure on a net basis, whereby we net positive and negative exposures for each counterparty with agreements in place. Netting positive and negative exposures would yield an exposure of $247.6 million, which is reduced to zero with pledged collateral at December 31, 2012. As of December 31, 2012, we held total collateral of $248.0 million in the form of cash and securities and we posted $296.9 million in cash and securities as collateral to our counterparties. We have not incurred any material losses on derivative financial instruments due to counterparty nonperformance. As a result of our management of our counterparty risk and the collateralization of our derivative portfolio, any deterioration in our derivative counterparties' credit would not materially impact our financial statements as of December 31, 2012.

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Item 8.    Financial Statements and Supplementary Data

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Report of Independent Registered Public Accounting Firm
on Internal Control Over Financial Reporting

The Board of Directors and Stockholders
Principal Financial Group, Inc.

        We have audited Principal Financial Group, Inc.'s internal control over financial reporting as of December 31, 2012, based on criteria established in Internal Control — Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission ("the COSO criteria"). Management of Principal Financial Group, Inc. ("the Company") is responsible for maintaining effective internal control over financial reporting, and for its assessment of the effectiveness of internal control over financial reporting included in the accompanying Management's Report on Internal Control Over Financial Reporting. Our responsibility is to express an opinion on the Company's internal control over financial reporting based on our audit.

        We conducted our audit in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether effective internal control over financial reporting was maintained in all material respects. Our audit included obtaining an understanding of internal control over financial reporting, assessing the risk that a material weakness exists, testing and evaluating the design and operating effectiveness of internal control based on the assessed risk, and performing such other procedures as we considered necessary in the circumstances. We believe that our audit provides a reasonable basis for our opinion.

        A company's internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles. A company's internal control over financial reporting includes those policies and procedures that (1) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company; (2) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the company are being made only in accordance with authorizations of management and directors of the company; and (3) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or disposition of the company's assets that could have a material effect on the financial statements.

        Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

        In our opinion, Principal Financial Group, Inc. maintained, in all material respects, effective internal control over financial reporting as of December 31, 2012, based on the COSO criteria.

        We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States), the consolidated statements of financial position of Principal Financial Group, Inc. as of December 31, 2012 and 2011, and the related consolidated statements of operations, comprehensive income, stockholders' equity and cash flows for each of the three years in the period ended December 31, 2012, and our report dated February 13, 2013, expressed an unqualified opinion thereon.

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Report of Independent Registered Public Accounting Firm

The Board of Directors and Stockholders
Principal Financial Group, Inc.

        We have audited the accompanying consolidated statements of financial position of Principal Financial Group, Inc. ("the Company") as of December 31, 2012 and 2011, and the related consolidated statements of operations, comprehensive income, stockholders' equity and cash flows for each of the three years in the period ended December 31, 2012. These financial statements are the responsibility of the Company's management. Our responsibility is to express an opinion on these financial statements based on our audits.

        We conducted our audits in accordance with the standards of the Public Company Accounting Oversight Board (United States). Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement. An audit includes examining, on a test basis, evidence supporting the amounts and disclosures in the financial statements. An audit also includes assessing the accounting principles used and significant estimates made by management, as well as evaluating the overall financial statement presentation. We believe that our audits provide a reasonable basis for our opinion.

        In our opinion, the financial statements referred to above present fairly, in all material respects, the consolidated financial position of Principal Financial Group, Inc. at December 31, 2012 and 2011, and the consolidated results of its operations and its cash flows for each of the three years in the period ended December 31, 2012, in conformity with U.S. generally accepted accounting principles.

        As discussed in Note 1 to the consolidated financial statements, in response to new accounting standards, the Company changed its methods of accounting for the capitalization of deferred policy acquisition costs effective January 1, 2012, for credit derivatives embedded in beneficial interests in securitized financial assets effective July 1, 2010 and for variable interest entities effective January 1, 2010. In addition, the Company has elected to change its methods of accounting for the cost of long duration universal life and variable universal life reinsurance contracts and for the estimated gross profits of these contracts effective January 1, 2012.

        We also have audited, in accordance with the standards of the Public Company Accounting Oversight Board (United States), the Company's internal control over financial reporting as of December 31, 2012, based on criteria established in Internal Control — Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission and our report dated February 13, 2013, expressed an unqualified opinion thereon.

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Principal Financial Group, Inc.

Consolidated Statements of Financial Position

See accompanying notes.

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Principal Financial Group, Inc.

Consolidated Statements of Operations

See accompanying notes.

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Principal Financial Group, Inc.

Consolidated Statements of Comprehensive Income

See accompanying notes.

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Principal Financial Group, Inc.

Consolidated Statements of Stockholders' Equity

See accompanying notes.

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Principal Financial Group, Inc.

Consolidated Statements of Cash Flows

See accompanying notes.

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Principal Financial Group, Inc.

Notes to Consolidated Financial Statements

December 31, 2012

1. Nature of Operations and Significant Accounting Policies

Description of Business

        Principal Financial Group, Inc. ("PFG"), along with its consolidated subsidiaries, is a diversified financial services organization engaged in promoting retirement savings and investment and insurance products and services in the U.S. and selected international markets.

Basis of Presentation

        The accompanying consolidated financial statements include the accounts of PFG and all other entities in which we directly or indirectly have a controlling financial interest as well as those variable interest entities ("VIEs") in which we are the primary beneficiary. Entities in which we have significant management influence over the operating and financing decisions but are not required to consolidate, other than investments accounted for at fair value under the fair value option, are reported using the equity method. The consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles ("U.S. GAAP"). All significant intercompany accounts and transactions have been eliminated.

        Reclassifications have been made to prior period financial statements to conform to the December 31, 2012, presentation.

Closed Block

        Principal Life Insurance Company ("Principal Life") operates a closed block ("Closed Block") for the benefit of individual participating dividend-paying policies in force at the time of the 1998 mutual insurance holding company ("MIHC") formation. See Note 6, Closed Block, for further details.

Accounting Changes

        In October 2010, the Financial Accounting Standards Board ("FASB") issued authoritative guidance that modifies the definition of the types of costs incurred by insurance entities that can be capitalized in the successful acquisition of new or renewal insurance contracts. Capitalized costs should include incremental direct costs of contract acquisition, as well as certain costs related directly to acquisition activities such as underwriting, policy issuance and processing, medical and inspection and sales force contract selling. This guidance was effective for us on January 1, 2012, and we adopted the guidance retrospectively.

        Effective January 1, 2012, we elected to change our methods of accounting for the cost of long duration universal life and variable universal life reinsurance contracts and for the estimated gross profits ("EGPs") of these contracts. These changes are collectively referred to as the "Reinsurance Accounting Change". Under our previous method, we recognized all reinsurance cash flows as part of the net cost of reinsurance and amortized this balance over the estimated lives of the underlying policies in proportion to the pattern of EGPs on the underlying policies. Under the new method, any difference between actual and expected reinsurance cash flows is recognized in earnings immediately instead of being deferred and amortized over the life of the underlying policies. In conjunction with this change, we also changed our policy for determining EGPs relating to these contracts to include the difference between actual and expected reinsurance cash flows, where previously these effects had not been included. We adopted the new policies because we believe that they better reflect the economics of our reinsurance transactions by accounting for direct claims and related reinsurance recoveries in the same period. In addition, the new policies are consistent with our intent to purchase reinsurance to protect us against large and unexpected claims.

        Comparative amounts from prior periods have been adjusted to apply the new deferred policy acquisition cost ("DPAC") guidance ("DPAC Guidance") and the Reinsurance Accounting Change retrospectively in these financial statements.

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Principal Financial Group, Inc.

Notes to Consolidated Financial Statements — (continued)

December 31, 2012

1. Nature of Operations and Significant Accounting Policies — (continued)

        Our retrospective adoption of the DPAC Guidance and the Reinsurance Accounting Change resulted in reductions to the opening balances of retained earnings and accumulated other comprehensive income ("AOCI") as of January 1, 2010, as shown in the following table.

        The following tables show the prior period financial statement line items that were affected by the DPAC Guidance and the Reinsurance Accounting Change.

Consolidated Statements of Financial Position

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Principal Financial Group, Inc.

Notes to Consolidated Financial Statements — (continued)

December 31, 2012

1. Nature of Operations and Significant Accounting Policies — (continued)

Consolidated Statements of Operations