X0306 4 2022-03-02 0 0001610950 Syneos Health, Inc. SYNH 0001892101 Brooks Michael Lee C/O SYNEOS HEALTH, INC. 1030 SYNC STREET MORRISVILLE NC 27560 0 1 0 0 See remarks Class A Common Stock 2022-03-02 4 A 0 1324 0.00 A 36777 D Class A Common Stock 10842 I By spouse Represents performance restricted stock units that were earned based upon performance criteria for the year ended December 31, 2021 and will vest in full once the Compensation and Management Development Committee of the Board of Directors of Syneos Health, Inc. determines the attainment level of the performance goals for the year ended December 31, 2023, subject to continued employment. Chief Development Officer & Global Head Clinical Development Solutions /s/ Sara Epstein, Attorney-in-Fact 2022-03-04