X0508 4 2023-09-14 0 0001861795 Definitive Healthcare Corp. DH 0001879228 Mirisola Joseph Gianni C/O DEFINITIVE HEALTHCARE CORP. 492 OLD CONNECTICUT PATH, SUITE 401 FRAMINGHAM MA 01701 0 1 0 0 Chief Revenue Officer 0 Class A common stock 2023-09-14 4 F 0 1044 8.27 D 185198 D The transaction reported represents the withholding of shares by the issuer to satisfy the reporting person's tax withholding obligations in connection with the vesting and settlement of previously reported restricted stock units. /s/ Matthew Ruderman, as attorney in fact 2023-09-18