X0508 4 2024-01-07 0 0001861795 Definitive Healthcare Corp. DH 0001390194 Musslewhite Robert W C/O DEFINITIVE HEALTHCARE CORP. 492 OLD CONNECTICUT PATH, SUITE 401 FRAMINGHAM MA 01701 1 1 0 0 Chief Executive Officer 0 Class A Common Stock 2024-01-07 4 F 0 14207 9.00 D 1201638 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 2024-01-09