X0306 4 2022-08-08 0001861795 Definitive Healthcare Corp. DH 0001813116 Winn David Randall 7900 GLADES ROAD SUITE 540 BOCA RATON FL 33434 true Class A Common Stock 2022-08-08 4 C 0 1948960 A 1948960 I By 22C Capital I, L.P. Class A Common Stock 2022-08-08 4 C 0 5763 A 5763 I By 22C AIDH AIV LLC Class A Common Stock 2022-08-08 4 S 0 245277 24.025 D 275650 I By 22C Capital I-A, L.P. Class A Common Stock 2022-08-08 4 S 0 1948960 24.025 D 0 I By 22C Capital I, L.P. Class A Common Stock 2022-08-08 4 S 0 5763 24.025 D 0 I By 22C AIDH AIV LLC LLC Units of AIDH Topco, LLC 2022-08-08 4 C 0 1948960 0 D Class A Common Stock 1948960 2190307 I By 22C Capital I, L.P. LLC Units of AIDH Topco, LLC 2022-08-08 4 C 0 5763 0 D Class A Common Stock 5763 6476 I By 22C AIDH AIV LLC 22C Capital GP I, L.L.C. is the general partner of 22C Capital I, L.P. and 22C Capital I-A, L.P. and is the sole member of 22C AIDH AIV LLC. 22C Capital GP I MM LLC is the managing member of 22C Capital GP I, L.L.C. The Reporting Person is one of the co-members of 22C Capital GP I MM LLC and, in such capacity, may be deemed to exercise voting or investment power over the shares of Class A common stock and LLC Units of AIDH Topco held directly by each of 22C Capital I, L.P., 22C Capital I-A, L.P. and 22C AIDH AIV LLC. The Reporting Person may exchange LLC Units of AIDH Topco, LLC for shares of Class A Common Stock of the Issuer on a one-for-one basis, subject to certain exceptions, conditions and adjustments. The LLC Units of AIDH Topco, LLC have no expiration date. At the time of any such exchange, an equal number of shares of Class B Common Stock of the Issuer held by the Reporting Person, which have no economic value and entitle holders thereof to one vote per share on all matters on which stockholders of the Issuer are entitled to vote generally, are cancelled. /s/ David Randall Winn 2022-08-10