AmBase Corp

The Annual Report of the Company on Form 10-K for the year ended December 31, 2024, is being mailed with this Proxy Statement to each stockholder entitled to vote at the Annual Meeting. Any stockholder who wishes to submit a nominee for election to the Board of Directors or a proposal for action to be included in the Proxy Statement for the Company’s 2025 Annual Meeting of Stockholders in accordance with Rule 14a-8 of the Securities Exchange Act and the Company’s by-laws must submit such proposal so that it is received by the Secretary of the Company by December 18, 2025.

The accompanying proxy is solicited by and on behalf of the Company’s Board of Directors. The cost of such solicitation will be borne by the Company. In addition to solicitation by mail, regular employees of the Company may, if necessary to assure the presence of a quorum, solicit proxies in person, or by telephone, facsimile or other electronic means. Arrangements have been made with brokerage houses and other custodians, nominees and fiduciaries, for the forwarding of solicitation material to the beneficial owners of Common Stock held of record by such persons, and the Company will reimburse such entities for reasonable out-of-pocket expenses incurred in connection therewith. The Company has engaged American Stock Transfer & Trust Company to assist in the tabulation of proxies.

If any matter not described in this Proxy Statement should properly come before the Annual Meeting, the persons named in the accompanying proxy will vote the shares represented by that proxy in accordance with their best judgment unless a stockholder, by striking out the appropriate provision of the proxy, chooses to withhold authority to vote on such matters. As of the date this Proxy Statement was printed, the directors knew of no other matters to be brought before the Annual Meeting.

Stockholder inquiries, including requests for the following: (i) change of address; (ii) replacement of lost stock certificates; (iii) Common Stock name registration changes; (iv) Quarterly Reports on Form 10-Q; (v) Annual Reports on Form 10-K; (vi) proxy material; and (vii) information regarding stockholdings, should be directed to:

American Stock Transfer & Trust Company, LLC 6201 15th Avenue Brooklyn, NY 11219 Attention: Stockholder Services (800) 937-5449 or (718) 921-8200 Ext. 6820

Copies of Quarterly Reports on Form 10-Q, Annual Reports on Form 10-K and Proxy Statements can also be obtained directly from the Company free of charge by sending a request to the Company by mail as follows:

AmBase Corporation 12 Lincoln Boulevard, Suite 202 Emerson, NJ 07630 Attn: Shareholder Services

In addition, the Company’s public reports, including Quarterly Reports on Form 10-Q, Annual Reports on Form 10-K and Proxy Statements, can be obtained through the SEC’s EDGAR Database over the internet at www.sec.gov.