Ownership Submission
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
OMB APPROVAL
OMB Number: 3235-0104
Expires: January 31, 2005
Estimated average burden hours per response... 0.5

(Print or Type Responses)
1. Name and Address of Reporting Person *
  DUNN RYAN C
 2. Date of Event Requiring Statement (Month/Day/Year)
03/22/2017		 3. Issuer Name and Ticker or Trading Symbol
ENTERPRISE BANCORP INC /MA/ [EBTC]
(Last)
(First)
(Middle)
C/O ENTERPRISE BANCORP, INC., 222 MERRIMACK STREET		 4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
EVP-Principal Subsidiary
 5. If Amendment, Date Original Filed(Month/Day/Year)
(Street)

LOWELL, MA 01852		 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 5,726.1734
D
 
Common Stock 38.1192
I
By Children

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly. SEC 1473 (7-02)
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.

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
Option (Right to Buy)   (1) 03/14/2018 Common Stock 750 $ 14.85 D  
Option (Right to Buy)   (2) 03/19/2019 Common Stock 850 $ 16.25 D  
Option (Right to Buy)   (3) 03/18/2023 Common Stock 900 $ 16.43 D  
Option (Right to Buy)   (4) 03/17/2024 Common Stock 805 $ 20.29 D  
Option (Right to Buy)   (5) 03/16/2025 Common Stock 795 $ 21.03 D  
Option (Right to Buy)   (6) 03/14/2026 Common Stock 793 $ 21.86 D  
Option (Right to Buy)   (7) 03/20/2027 Common Stock 364 $ 30.46 D  

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
DUNN RYAN C
C/O ENTERPRISE BANCORP, INC.
222 MERRIMACK STREET
LOWELL, MA 01852		       EVP-Principal Subsidiary  

Signatures

/s/ John P. Clancy, attorney-in-fact for Ryan C. Dunn 03/29/2017
**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) Options vested at 25% per year on the anniversary date of the grant with the first installment vesting on March 15, 2012. Options are fully vested.
(2) Options vested at 25% per year on the anniversary date of the grant with the first installment vesting on March 20, 2013. Options are fully vested.
(3) Options vest 50% on the second anniversary of the grant date and 50% on the fourth anniversary of the grant date. The first installment vested on March 19, 2015. Options are fully vested.
(4) Options vest 50% on the second anniversary date of the grant and 50% on the fourth anniversary date of the grant. The first installment vested on March 18, 2016.
(5) Options vest 50% on the second anniversary of the grant date and 50% on the fourth anniversary of the grant date. The first installment vested on March 17, 2017.
(6) Options vest 50% on the second anniversary of the grant date and 50% on the fourth anniversary of the grant date. The first installment vested on March 15, 2018.
(7) Options vest 50% on the second anniversary date of the grant and 50% on the fourth anniversary date of the grant. The first installment vests on March 21, 2019.

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, See Instruction 6 for procedure.

Potential persons who are to respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB number.