X0206 3 2018-09-13 0 0001610950 Syneos Health, Inc. SYNH 0001604098 THL Managers VI, LLC C/O THOMAS H. LEE PARNTERS, L.P. 100 FEDERAL STREET, 35TH FLOOR BOSTON MA 02110 true true 0001753032 THL Managers VII, LLC C/O THOMAS H LEE PARTNERS, L.P. 100 FEDERAL STREET, 35TH FLOOR BOSTON MA 02110 true true Class A Common Stock 4356 D This statement is being filed by the following Reporting Persons: THL Managers VI, LLC ("Managers VI") and THL Managers VII, LLC ("Managers VII"). Represents 3,148 shares of the Issuer directly owned by Managers VI and 1,208 shares of the Issuer directly owned by Managers VII. Each of the Reporting Persons disclaims beneficial ownership of all shares of the Issuer for the purposes of Section 16 or for any other purpose, except to the extent of such Reporting Person's pecuniary interest therein. Exhibit 99.1 (Joint Filer Information) is incorporated herein by reference. THL Managers VI, LLC /s/ Charles P. Holden Title: Managing Director 2018-09-24