8-K

UNITED STATESSECURITIES AND EXCHANGE COMMISSIONWASHINGTON, D.C. 20549

FORM 8-K

Current Report

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported):

April 3, 2026

Definitive Healthcare Corp.

(Exact name of Registrant as Specified in Its Charter)

(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 1.02 Termination of a Material Definitive Agreement.

Definitive Healthcare Corp. (the “Company”) and SE VII DHC AIV, L.P. (“Spectrum”), were parties to a Nominating Agreement, dated September 17, 2021 (the “Nominating Agreement”). The Nominating Agreement provides that, so long as Spectrum and/or its Affiliates were the Beneficial Owner of at least 5% of the total number of shares of Common Stock outstanding, the Nominating Agreement granted Spectrum, among other things, the right to designate one (1) person for inclusion in the slate of nominees recommended to the Company’s stockholders for election as directors of the Company (the “Spectrum Designee”).

On March 30, 2026, Jeff Haywood, the Spectrum Designee, resigned from the board of directors, and, on April 3, 2026, the Company and Spectrum entered into a termination agreement that permanently and irrevocably terminated the Nominating Agreement in its entirety.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.