SCHEDULE 13G 0001864851 XXXXXXXX LIVE Common Stock, par value $0.001 per share 06/30/2025 0002040491 Ategrity Specialty Insurance Company Holdings 04681Y103 9 West 57th Street 33rd Floor New York NY 10019 Rule 13d-1(d) Zimmer Financial Services Group LLC DE 0.00 39967192.00 0.00 39967192.00 39967192.00 N 80.7 HC OO Limited Liability Company Stuart J. Zimmer X1 0.00 40220522.00 0.00 40220522.00 40220522.00 N 81.2 IN Ategrity Specialty Insurance Company Holdings 9 West 57th Street, 33rd Floor, New York, NY, 10019 Each of the following is hereinafter individually referred to as a "Reporting Person" and collectively as the "Reporting Persons." This statement is filed on behalf of: (1) Zimmer Financial Services Group LLC ("ZFSG") (2) Stuart J. Zimmer The principal business address of each of the Reporting Persons is c/o Ategrity Specialty Insurance Company Holdings, 9 West 57th Street, 33rd Floor, New York, NY 10019. ZFSG is organized under the laws of the State of Delaware. Mr. Zimmer is a citizen of the United States. Y The information contained on the cover pages to this Schedule 13G is incorporated by reference into this Item 4. The ownership information presented herein represents beneficial ownership of Common Stock as of June 30, 2025, based upon 48,066,674 shares of Common Stock outstanding as of the closing of the Issuer's initial public offering on June 12, 2025. ZSFG is the record holder of 38,512,440 shares of Common Stock and 1,454,752 shares of Common Stock underlying warrants that are currently exercisable. Mr. Zimmer is the sole managing member of ZFSG and therefore may be deemed to share beneficial ownership of the securities held of record by ZFSG. Additionally, Mr. Zimmer may be deemed to beneficially own 253,330 shares of Common Stock held by certain trusts and estate planning vehicles of Mr. Zimmer. See Item 11 of each of the cover pages hereto. See Item 5 of each of the cover pages hereto. See Item 6 of each of the cover pages hereto. See Item 7 of each of the cover pages hereto. See Item 8 of each of the cover pages hereto. Y Y Y Y Y Y Exhibit 1: Joint Filing Agreement. Zimmer Financial Services Group LLC /s/ Stuart J. Zimmer 08/14/2025 Stuart J. Zimmer /s/ Stuart J. Zimmer 08/14/2025