X0306 4 2021-06-07 0001610950 Syneos Health, Inc. SYNH 0001260943 THOMAS H. LEE ADVISORS, LLC C/O THOMAS H. LEE PARTNERS, L.P. 100 FEDERAL STREET, 35TH FLOOR BOSTON MA 02110 true 0001713702 THL Fund VII Coinvestment Partners, L.P. C/O THOMAS H. LEE PARTNERS, L.P. 100 FEDERAL STREET, 35TH FLOOR BOSTON MA 02110 true 0001665668 THL Executive Fund VII, L.P. C/O THOMAS H. LEE PARTNERS, L.P. 100 FEDERAL STREET, 35TH FLOOR BOSTON MA 02110 true 0001713160 THL Equity Fund VII Investors (inVentiv), L.P. C/O THOMAS H. LEE PARTNERS, L.P. 100 FEDERAL STREET, 35TH FLOOR BOSTON MA 02110 true Class A Common Stock 2021-06-07 4 S 0 4816880 81.2 D 391991 I See footnote Class A Common Stock 2021-06-07 4 S 0 226128 81.2 D 0 I See footnote Class A Common Stock 2021-06-07 4 S 0 815 81.2 D 37 D Class A Common Stock 2021-06-07 4 S 0 313 81.2 D 14 D Class A Common Stock 2021-06-07 4 S 0 37 81.2 D 0 D Class A Common Stock 2021-06-07 4 S 0 14 81.2 D 0 D See Exhibit 99.1 for text of footnote (1). See Exhibit 99.1 for text of footnote (2). See Exhibit 99.1 for text of footnote (3). See Exhibit 99.1 for text of footnote (4). See Exhibit 99.1 for text of footnote (5). See Exhibit 99.1 for text of footnote (6). See Exhibit 99.1 for text of footnote (7). See Exhibit 99.1 for text of footnote (8). See Exhibit 99.1 for text of footnote (9). See Exhibit 99.1 for text of footnote (10). See Exhibit 99.1 for text of footnote (11). See Exhibit 99.1 for text of footnote (12). See Exhibit 99.1 for text of footnote (13). See Exhibit 99.1 for text of footnote (14). See Exhibit 99.1 for text of footnote (15). Exhibit 99.1 (Form 4 Footnotes) and Exhibit 99.2 (Joint Filer Information) are incorporated herein by reference. This Form 4 is the second of two Forms 4 being filed relating to the same event. The Form 4 has been split into two 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 Reporting Persons. Each Form 4 will be filed by Designated Filer Thomas H. Lee Advisors, LLC. ** See Exhibit 99.2 for Signatures 2021-06-09