FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person *   Tyler Brian Scott 2. Date of Event Requiring Statement (Month/Day/Year) 08/23/2012 3. Issuer Name and Ticker or Trading Symbol MCKESSON CORP [MCK] (Last) (First) (Middle) ONE POST STREET 4. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) EVP, Corp Strategy & Bus. Dev. 5. If Amendment, Date Original Filed(Month/Day/Year) (Street) SAN FRANCISCO, CA 94104 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Beneficially Owned

1.Title of Security (Instr. 4) 2. Amount of Securities Beneficially Owned (Instr. 4) 3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 4. Nature of Indirect Beneficial Ownership (Instr. 5) Common Stock 5 D   Common Stock 198.1859 I By Profit-Sharing Investment Plan

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.			SEC 1473 (7-02)
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Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Employee Stock Option (Right-to-buy)	  (1)	05/20/2015	Common Stock	4,000	$ 57.89	D	Â
Employee Stock Option (Right-to-buy)	  (2)	05/26/2016	Common Stock	6,250	$ 40.46	D	Â
Employee Stock Option (Right-to-buy)	  (3)	05/25/2017	Common Stock	20,000	$ 67.81	D	Â
Restricted Stock Units (RSUs)	  (4)	  (4)	Common Stock	12,597	$ 0	D	Â
Employee Stock Option (Right-to-buy)	  (5)	01/25/2018	Common Stock	25,000	$ 74.57	D	Â
Restricted Stock Units (RSUs)	  (6)	  (6)	Common Stock	10,000	$ 0	D	Â
Employee Stock Option (Right-to-buy)	  (7)	05/24/2018	Common Stock	36,000	$ 83.51	D	Â
Restricted Stock Units (RSUs)	  (8)	  (8)	Common Stock	8,190	$ 0	D	Â
Restricted Stock Units (RSUs)	  (9)	  (9)	Common Stock	480	$ 0	D	Â
Restricted Stock Units (RSUs)	  (10)	  (10)	Common Stock	78,381	$ 0	D	Â
Employee Stock Option (Right-to-buy)	  (11)	05/22/2019	Common Stock	33,000	$ 87.24	D	Â
Restricted Stock Units (RSUs)	  (12)	  (12)	Common Stock	15,696	$ 0	D	Â

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Tyler Brian Scott ONE POST STREET SAN FRANCISCO, CA 94104	Â	Â	  EVP, Corp Strategy & Bus. Dev.	Â

Signatures

Donna Spinola, Attorney-in-fact		08/31/2012
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 5(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	This option granted 05/20/2008 vested 25% over four years commencing on the 1st anniversary of the grant date.
(2)	This option granted 05/26/2009 vests 25% over four years commencing on the 1st anniversary of the grant date.
(3)	This option granted 05/25/2010 vests 25% over four years commencing on the 1st anniversary of the grant date.
(4)	These RSUs vest 100% on 05/26/2013.
(5)	This option granted 01/25/2011 vests 25% over four years commencing on the 1st anniversary of the grant date.
(6)	These RSUs vest 100% on 01/25/2015.
(7)	This option granted 05/24/2011 vests 25% over four years commencing on the 1st anniversary of the grant date.
(8)	These RSUs vest 100% on 05/24/2014.
(9)	These RSUs vest 100% on 10/28/2014.
(10)	These RSUs vest 100% on 01/24/2018.
(11)	This option granted 05/22/2012 vests 25% over four years commencing on the 1st anniversary of the grant date.
(12)	These RSUs vest 100% on 05/24/2015.

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