SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* ADVENT INTERNATIONAL CORP/MA (Last) (First) (Middle) PRUDENTIAL TOWER, 800 BOYLSTON STREET SUITE 3300 (Street) BOSTON MA 02199-8069 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol Syneos Health, Inc. [ SYNH ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) Other (specify below)
	3. Date of Earliest Transaction (Month/Day/Year) 12/03/2020
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X Form filed by More than One Reporting Person

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
Class A Common Stock	12/03/2020		S(1)		3,228,241(1)	D	$61.28	15,418,795(2)	I	See Notes(3)(4)

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 Securities Underlying Derivative Security (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: 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

1. Name and Address of Reporting Person* ADVENT INTERNATIONAL CORP/MA (Last) (First) (Middle) PRUDENTIAL TOWER, 800 BOYLSTON STREET SUITE 3300 (Street) BOSTON MA 02199-8069 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Advent International GPE VII-G Limited Partnership (Last) (First) (Middle) C/O ADVENT INTERNATIONAL CORPORATION 800 BOYLSTON STREET, SUITE 3300 (Street) BOSTON MA 02199-8069 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Advent International GPE VII-F Limited Partnership (Last) (First) (Middle) C/O ADVENT INTERNATIONAL CORPORATION 800 BOYLSTON STREET, SUITE 3300 (Street) BOSTON MA 02199-8069 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Advent International GPE VII-D Limited Partnership (Last) (First) (Middle) C/O ADVENT INTERNATIONAL CORPORATION 800 BOYLSTON STREET, SUITE 3300 (Street) BOSTON MA 02199-8069 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

Explanation of Responses:

1. See Exhibit 99.1 for text of footnote (1).

2. See Exhibit 99.1 for text of footnote (2).

3. See Exhibit 99.1 for text of footnote (3).

4. See Exhibit 99.1 for text of footnote (4).

Remarks:

Exhibit 99.1 (Footnotes to Form 4) and Exhibit 99.2 (Signatures and Joint Filer Information) are incorporated herein by reference. This Form 4 is the sixth of six Form 4s being filed relating to the same event. This Form 4 has been split into six filings because there are more than 10 Reporting Persons in total, and the SEC's EDGAR filing system limits a single Form 4 to a maximum of 10. Each part will be filed by Designated Filer, Advent International Corporation.

	See Exhibit 99.2	12/07/2020
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* 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).
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