If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box. Checkbox not checked

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).




schemaVersion:


SCHEDULE 13D




Comment for Type of Reporting Person:
The reported percentage is calculated based on 106,744,713 shares of Class A Common Stock ("Common Stock") outstanding as of August 6, 2026, as reported on the Issuer's 10-Q filed with the Securities and Exchange Commission ("SEC") on August 10, 2026.


SCHEDULE 13D




Comment for Type of Reporting Person:
The reported percentage is calculated based on 106,744,713 shares of Common Stock outstanding as of August 6, 2026, as reported on the Issuer's 10-Q filed with the SEC on August 10, 2026.


SCHEDULE 13D




Comment for Type of Reporting Person:
The reported percentage is calculated based on 106,744,713 shares of Common Stock outstanding as of August 6, 2026, as reported on the Issuer's 10-Q filed with the SEC on August 10, 2026.


SCHEDULE 13D




Comment for Type of Reporting Person:
The reported percentage is calculated based on 106,744,713 shares of Common Stock outstanding as of August 6, 2026, as reported on the Issuer's 10-Q filed with the SEC on August 10, 2026.


SCHEDULE 13D


 
Advent International, L.P.
 
Signature:/s/ Neil Crawford
Name/Title:Neil Crawford / Senior Director, Fund Administration of Advent International GP, LLC, its General Partner
Date:09/02/2026
 
Advent International GP, LLC
 
Signature:/s/ Neil Crawford
Name/Title:Neil Crawford / Senior Director, Fund Administration
Date:09/02/2026
 
Advent International GPE IX Limited Partnership
 
Signature:/s/ Neil Crawford
Name/Title:Neil Crawford / Senior Director, Fund Administration of Advent International GP, LLC, its indirect General Partner
Date:09/02/2026
 
Advent International GPE IX-H Limited Partnership
 
Signature:/s/ Neil Crawford
Name/Title:Neil Crawford / Senior Director, Fund Administration of Advent International GP, LLC, its indirect General Partner
Date:09/02/2026
Comments accompanying signature:
Each of Advent International GPE IX Limited Partnership and Advent International GPE IX-H Limited Partnership, By: GPE IX GP Limited Partnership, their General Partner, By: Advent International GPE IX, LLC, its General Partner, By: Advent International, L.P., its Manager, By: Advent International GP, LLC, its General Partner.

EXHIBIT 24
 
JOINT FILING AGREEMENT
 
In accordance with Rule 13d-1(k)(1) promulgated under the Securities Exchange Act of 1934, as amended, the undersigned hereby agree that this Statement is being jointly filed, and all amendments thereto will be jointly filed, by Advent International, L.P., as the main and designated filer, on behalf of each of the entities named below that is named as a reporting person in such filing. Each of the undersigned is responsible for the timely filing of this Statement and any amendments thereto, and for the completeness and accuracy of the information concerning such person contained therein; but none of them is responsible for the completeness or accuracy of the information concerning the other persons making the filing, unless such person knows or has reason to believe that such information is inaccurate. This Agreement may be executed in two or more counterparts, each of which shall be deemed an original, but all of which together shall constitute one and the same instrument.
 
Date: September 2, 2026
 
 
ADVENT INTERNATIONAL, L.P.
   
 
By: ADVENT INTERNATIONAL GP, LLC, GENERAL PARTNER
   
 
/s/ Neil Crawford
 
Name: Neil Crawford
 
Title: Senior Director, Fund Administration
   
 
ADVENT INTERNATIONAL GP, LLC
   
 
/s/ Neil Crawford
 
Name: Neil Crawford
 
Title: Senior Director, Fund Administration
 
 
ADVENT INTERNATIONAL GPE IX LIMITED PARTNERSHIP
 
ADVENT INTERNATIONAL GPE IX-H LIMITED PARTNERSHIP
   
 
By: GPE IX GP LIMITED PARTNERSHIP, GENERAL PARTNER
 
By: ADVENT INTERNATIONAL GPE IX, LLC, GENERAL PARTNER
 
By: ADVENT INTERNATIONAL, L.P., MANAGER
 
By: ADVENT INTERNATIONAL GP, LLC, GENERAL PARTNER
   
 
/s/ Neil Crawford
 
Name: Neil Crawford
 
Title: Senior Director, Fund Administration
 
 


EXHIBIT 99.1
 
BOARD OF MANAGERS OF ADVENT INTERNATIONAL GP, LLC
 
The name, present principal occupation or employment, and citizenship of each of the members of the Board of Managers of Advent International GP, LLC are set forth below. Each manager’s business address is c/o Advent International, L.P., Prudential Tower, 800 Boylston Street, Boston, MA, 02199. Each occupation set forth opposite an individual’s name refers to Advent International GP, LLC.
 
   
Name
Present Principal Occupation
Citizenship
James Brocklebank
Manager
United Kingdom
John Maldonado
Manager
United States of America
Jeff Paduch
Manager
United States of America
 
 


EXHIBIT 99.2

September 1, 2026


Special Committee of the Board of Directors (the “Special Committee”)
Definitive Healthcare Corp.
492 Old Connecticut Path, Suite 401
Framingham, MA 01701

Re: Non-Binding Offer to Acquire Definitive Healthcare Corp. (the “Company”)

Dear Members of the Special Committee:

Advent International, L.P., on behalf of certain of its managed funds (collectively, “Advent”), is pleased to submit this non-binding indication of interest (the “Proposal”) to acquire all the outstanding shares of the Company’s Class A common stock (the “Class A Common Stock”) and all of the outstanding limited liability company interests of AIDH TopCo, LLC (the “Definitive OpCo Units”), in each case, that are not already owned by Advent and stockholder Jason Krantz, as described below, for an all-cash purchase price of $1.02 per share of Class A Common Stock and an equivalent amount per Definitive Opco Unit (the “Potential Transaction”). The proposed purchase price represents a premium of 36% to the Company’s 60-day volume-weighted average daily trading price of $0.75 per share of Class A Common Stock as of market close on August 31, 2026. As such, this Proposal would provide the Company’s stockholders with an opportunity to realize immediate liquidity at a significant premium.

As a longtime stockholder, we have a deep understanding and appreciation of the Company’s business and the opportunities and challenges facing the Company.  We believe that we are uniquely positioned to timely execute an acquisition of the Company on attractive terms for the Company’s stockholders. Given our familiarity with the Company, we are prepared to move forward to negotiate and execute definitive transaction documentation in an expeditious manner.

This Proposal is premised on Jason Krantz, Executive Chairman and founder of the Company, rolling over his Class A Common Stock and Definitive OpCo Units into equity of the surviving company. This Proposal is not subject to any financing condition.

While any Potential Transaction will be subject to customary approvals and closing conditions, we do not anticipate substantial regulatory or other hurdles or delays to consummating a Potential Transaction. We will not proceed with a Potential Transaction without the approval of the Special Committee, comprised entirely of disinterested and independent directors that has been expressly delegated the authority to negotiate or oversee the negotiation of a potential transaction and to reject such transaction. We expect that any such special committee would be advised by independent legal and financial advisors.

As required by applicable law, we intend to file a Schedule 13D, including a copy of this letter, with the Securities and Exchange Commission.


This letter and the Proposal constitute a non-binding indication of interest in a transaction with the Company and are not intended to create a legally binding obligation or agreement concerning the Potential Transaction, which is expressly subject to the negotiation and execution of appropriate and acceptable definitive agreements. We reserve the right to withdraw or modify this Proposal at any time.

We look forward to the opportunity to work with the Special Committee to move quickly toward a successful transaction.

Sincerely,


/s/ Chris Egan
 
/s/ Lauren Young
 
Chris Egan   Lauren Young  
Managing Partner   Managing Director
 
Advent International L.P.   Advent International L.P.