X0306 4 2020-09-17 0001610950 Syneos Health, Inc. SYNH 0001034196 ADVENT INTERNATIONAL CORP/MA PRUDENTIAL TOWER, 800 BOYLSTON STREET SUITE 3300 BOSTON MA 02199-8069 true 0001712399 Double Eagle Investor Holdings, L.P. C/O ADVENT INTERNATIONAL CORPORATION 800 BOYLSTON STREET, SUITE 3300 BOSTON MA 02199-8069 true 0001712398 Double Eagle GP, LLC C/O ADVENT INTERNATIONAL CORPORATION 800 BOYLSTON STREET, SUITE 3300 BOSTON MA 02199-8069 true 0001664591 Advent International GPE VIII-C Limited Partnership C/O ADVENT INTERNATIONAL CORPORATION 800 BOYLSTON STREET, SUITE 3300 BOSTON MA 02199-8069 true 0001764293 GPE VIII GP S.a.r.l. C/O ADVENT INTERNATIONAL CORPORATION 800 BOYLSTON STREET, SUITE 3300 BOSTON MA 02199-8069 true 0001714525 GPE VIII GP Limited Partnership C/O ADVENT INTERNATIONAL CORPORATION 800 BOYLSTON STREET, SUITE 3300 BOSTON MA 02199-8069 true 0001713142 Advent International GPE VIII, LLC C/O ADVENT INTERNATIONAL CORPORATION 800 BOYLSTON STREET, SUITE 3300 BOSTON MA 02199-8069 true 0001764292 GPE VII GP S.a.r.l. CO ADVENT INTERNATIONAL 800 BOYLSTON STREET BOSTON MA 02199 true 0001616580 GPE VII GP Limited Partnership C/O ADVENT INTERNATIONAL CORPORATION 800 BOYLSTON STREET, SUITE 3300 BOSTON MA 02199-8069 true 0001616626 Advent International GPE VII, LLC C/O ADVENT INTERNATIONAL CORPORATION 800 BOYLSTON STREET, SUITE 3300 BOSTON MA 02199-8069 true Class A Common Stock 2020-09-17 4 S 0 3766281 59.26 D 18647036 I See Notes 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). 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 first of six Form 4s being filed relating to the same event. The 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 Form 4 will be filed by Designated Filer, Advent International Corporation. See Exhibit 99.2 2020-09-21