Ategrity Specialty Insurance Co Holdings

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

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SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of

the Securities Exchange Act of 1934

Filed by the Registrant☒

Filed by a Party other than the Registrant☐

Check the appropriate box:

(Name of Registrant as Specified in its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of filing fee (Check the appropriate box):

Dear Stockholder:

You are cordially invited to attend the 2026 Annual Meeting of Stockholders of Ategrity Specialty Insurance Company Holdings, which will be held on Tuesday, June 9, 2026 at 11:00 a.m., Eastern Time, in a virtual format at www.virtualshareholdermeeting.com/ASIC2026

The accompanying Notice of Annual Meeting of Stockholders and Proxy Statement describe the matters expected to be acted upon at the Annual Meeting, including the election of directors and the ratification of the appointment of Ernst & Young LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2026.

Your vote is important. Whether or not you attend the Annual Meeting online, it is important that your shares be represented and voted at the Annual Meeting. Therefore, I urge you to promptly vote and submit your proxy by phone, via the Internet, or, if you received paper copies of these materials, by signing, dating and returning the enclosed proxy card in the enclosed envelope, which requires no postage if mailed in the United States. If you have previously received our Notice of Internet Availability of Proxy Materials, then instructions regarding how you can vote are contained in that notice. If you have received a proxy card, then instructions regarding how you can vote are contained on the proxy card. If you decide to attend the Annual Meeting, you will be able to vote online, even if you have previously submitted your proxy. You may revoke your proxy at any time before it is voted at the Annual Meeting.

Thank you for your continued support of Ategrity.

Sincerely,

Chief Executive Officer

NOTICE OF ANNUAL MEETING OF STOCKHOLDERS

TO BE HELD ON TUESDAY, JUNE 9, 2026

The 2026 Annual Meeting of Stockholders of Ategrity Specialty Insurance Company Holdings (the “Annual Meeting”) will be held on Tuesday, June 9, 2026, at 11:00 a.m., Eastern Time, in a virtual format at www.virtualshareholdermeeting.com/ASIC2026, for the following purposes:

•To elect seven directors to serve until the 2027 annual meeting of stockholders and until their respective successors are duly elected and qualified, or until their earlier death, resignation, disqualification or removal;

•To ratify the appointment of Ernst & Young LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2026; and

•To transact such other business as may properly come before the Annual Meeting or any adjournment or postponement thereof.

The Board of Directors has fixed the close of business on April 16, 2026 as the record date for determining the stockholders entitled to notice of, and to vote at, the Annual Meeting and any adjournment or postponement thereof.

By Order of the Board of Directors,

/s/ Eric Crespolini

Eric Crespolini

General Counsel

New York, New York

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