Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN 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 *
Haines Timothy
  2. Issuer Name and Ticker or Trading Symbol
Sientra, Inc. [SIEN]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director __X__ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
C/O 420 SOUTH FAIRVIEW, SUITE 200
3. Date of Earliest Transaction (Month/Day/Year)
06/22/2017
(Street)

SANTA BARBARA, CA 93117
4. If Amendment, Date Original Filed(Month/Day/Year)
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 Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)
2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)
4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)
6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)
7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock 06/22/2017   A   12,861 (1) A $ 9.72 31,546 D  
Common Stock               2,199,012 I See Note (2) (3)

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)
2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)
5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)
6. Date Exercisable and Expiration Date
(Month/Day/Year)
7. Title and Amount of Underlying Securities
(Instr. 3 and 4)
8. Price of Derivative Security
(Instr. 5)
9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)
10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)
11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
Haines Timothy
C/O 420 SOUTH FAIRVIEW, SUITE 200
SANTA BARBARA, CA 93117
  X   X    

Signatures

 /s/ Timothy Haines   06/26/2017
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(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) The common stock underlying this grant of restricted stock will vest on the earlier to occur of: (i) day prior to the annual meeting of stockholders for the year following the date of grant, or (ii) the one-year anniversary of the annual meeting of stockholders of the year of grant, subject to continued service as a director.
(2) Consists of (i) 1,099,506 shares held of record by Abingworth Bioventures V LP, or ABV V, and (ii) 1,099,506 shares held of record by Abingworth Bioventures V Co-Invest Growth Equity Fund LP, or AGE. ABV V and AGE are collectively referred to as the "Abingworth Funds." The investment manager of the Abingworth Funds is Abingworth LLP, or Abingworth. Abingworth Bioventures V GP LP, or Abingworth GP, a Scottish limited partnership, serves as the general partner of each of the Abingworth Funds. Abingworth General Partner V LLP, a Scottish limited liability partnership, serves as the general partner of Abingworth GP. Abingworth GP (acting by its general partner Abingworth General Partner V LLP) has delegated to Abingworth all investment and dispositive power over the shares held by the Abingworth Funds.
(3) The reporting person holds the reported securities indirectly through the Abingworth Funds. The reporting person disclaims beneficial ownership of such shares, except to the extent of its pecuniary interest therein. This report shall not be deemed an admission that the reporting person, the Abingworth Funds or any other person is the beneficial owner of the securities reported herein for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.

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