X0306 4 2019-04-30 true 0001610950 Syneos Health, Inc. SYNH 0001375668 Thomas H. Lee Equity Fund VI, L.P. C/O THOMAS H. LEE PARTNERS, L.P. 100 FEDERAL STREET, 35TH FLOOR BOSTON MA 02110 true true 0001429870 Thomas H. Lee Parallel (DT) Fund VI, L.P. C/O THOMAS H. LEE PARTNERS, L.P. 100 FEDERAL STREET, 35TH FLOOR BOSTON MA 02110 true true 0001375663 Thomas H. Lee Parallel Fund VI, L.P. C/O THOMAS H. LEE PARTNERS, L.P. 100 FEDERAL STREET, 35TH FLOOR BOSTON MA 02110 true true 0001429869 THL Coinvestment Partners, L.P. C/O THOMAS H. LEE PARTNERS, L.P. 100 FEDERAL STREET, 35TH FLOOR BOSTON MA 02110 true true 0001429868 THL Operating Partners, L.P. C/O THOMAS H. LEE PARTNERS, L.P. 100 FEDERAL STREET, 35TH FLOOR BOSTON MA 02110 true true 0001604101 Great-West Investors LP C/O THOMAS H. LEE PARTNERS, L.P. 100 FEDERAL STREET, 35TH FLOOR BOSTON MA 02110 true true 0001545929 Putnam Investments Employees' Securities Co III LLC C/O THOMAS H. LEE PARTNERS, L.P. 100 FEDERAL STREET, 35TH FLOOR BOSTON MA 02110 true true Class A Common Stock 2019-04-30 4 J 0 5504340 43.31 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). Exhibit 99.1 (Form 4 Footnotes) and Exhibit 99.2 (Joint Filer Information) are incorporated herein by reference. This Form 4 is filed by Designated Filer Thomas H. Lee Equity Fund VI, L.P. THOMAS H. LEE EQUITY FUND VI, L.P. /s/ Charles P. Holden Signature of Reporting Person Name: Charles P. Holden Title: Managing Director 2019-06-26 By: THL Equity Advisors VI, LLC, its General Partner /s/ Charles P. Holden Signature of Reporting Person Name: Charles P. Holden Title: Managing Director 2019-06-26 By: Thomas H. Lee Partners, L.P., its Sole Member /s/ Charles P. Holden Signature of Reporting Person Name: Charles P. Holden Title: Managing Director 2019-06-26 By: Thomas H. Lee Advisors, LLC, its General Partner /s/ Charles P. Holden Signature of Reporting Person Name: Charles P. Holden Title: Managing Director 2019-06-26 By: THL Holdco, LLC, its Managing Member /s/ Charles P. Holden Signature of Reporting Person Name: Charles P. Holden Title: Managing Director 2019-06-26