X0306 4 2022-10-07 0 0001861795 Definitive Healthcare Corp. DH 0001390194 Musslewhite Robert W C/O DEFINITIVE HEALTHCARE CORP. 550 COCHITUATE RD FRAMINGHAM MA 01701 1 1 0 0 Chief Executive Officer Class A Common Stock 2022-10-07 4 F 0 70658 14.82 D 995997 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/ David Samuels, as attorney-in-fact 2022-10-12