Organization, Consolidation and Presentation	12 Months Ended
Dec. 31, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization, Consolidation and Presentation	1) ORGANIZATION, CONSOLIDATION AND PRESENTATION (a) Business American Coastal Insurance Corporation (referred to in this document as we, our, us, the Company or ACIC) is a property and casualty insurance holding company that sources, writes and services residential commercial property insurance policies using a network of agents and one wholly owned insurance subsidiary, American Coastal Insurance Company (AmCoastal), acquired via merger on April 3, 2017. On July 10, 2023, we changed our corporate name from United Insurance Holdings Corp. to American Coastal Insurance Corporation. The Company also previously wrote insurance through Interboro Insurance Company (IIC); however, on April 1, 2025, the Company completed the sale of IIC. The details of this transaction are described below. The Company's other subsidiaries include Skyway Underwriters, LLC, a managing general agent that provides policy and claims administration, underwriting, technological and distribution services to the Company's insurance company; AmCo Holding Company, LLC (AmCo), which is a holding company subsidiary that consolidates its respective insurance company; BlueLine Cayman Holdings (BlueLine), which reinsures portfolios of excess and surplus policies; and Shoreline Re, which provides a portion of the reinsurance protection purchased by the Company's insurance subsidiary where management deems prudent. The Company also has several subsidiaries in run-off including United Insurance Management, L.C. (UIM), a managing general agent; Skyway Claims Services, LLC (SCS), which previously provided claims adjusting services to the Company's insurance companies; Skyway Reinsurance Services, LLC, which previously provided reinsurance brokerage services for the Company's insurance companies; and Skyway Legal Services, LLC (SLS), which previously provided claims litigation services to the Company's insurance companies. We write commercial residential property insurance in Florida. On February 27, 2023, our former insurance subsidiary that wrote personal residential business in six states, United Property & Casualty Insurance Company (UPC), was placed into receivership with the Florida Department of Financial Services (DFS), which divested our ownership of UPC. The events leading to receivership and results of this subsidiary, now included within discontinued operations, are discussed in Note 4 below. On May 9, 2024, we entered into a Stock Purchase Agreement (the "Sale Agreement") with Forza Insurance Holdings, LLC (Forza) in which we agreed to sell and Forza agreed to acquire 100% of the issued and outstanding stock of IIC. Forza’s application to acquire IIC was approved by the New York Department of Financial Services (NYDFS) on February 13, 2025 and the sale closed on April 1, 2025. The aggregate purchase price for the shares was equal to IIC's shareholders' equity under U.S. generally accepted accounting principles (GAAP) on the closing date. IIC results of operations and assets and liabilities are captured within discontinued operations and are discussed in Note 4 of the Notes to Consolidated Financial Statements below. As a result of the Sale Agreement described above, IIC is presented as discontinued operations. The remaining activity captured within continuing operations supports only our commercial residential insurance offerings. Given this fact pattern, we conduct our operations under one operating segment, which consists of our commercial lines business. Further information regarding this segment can be seen in Not e 2(j) below. (b) Consolidation and Presentation We prepare our consolidated financial statements in conformity with U.S. generally accepted accounting principles (GAAP). While preparing our consolidated financial statements, we make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the consolidated financial statements, as well as reported amounts of revenues and expenses during the reporting period. Accordingly, actual results could differ from those estimates. Reported amounts that require us to make extensive use of estimates include our reserves for unpaid losses and loss adjustment expenses, investments and goodwill. Except for the captions on our Consolidated Balance Sheets and Consolidated Statements of Comprehensive Income (Loss), we generally use the term loss(es) to collectively refer to both loss and loss adjustment expenses. We include all our subsidiaries in our consolidated financial statements, eliminating intercompany balances and transactions during consolidation. As described in Note 2, our former subsidiaries, IIC and UPC, and activities related directly to supporting the business conducted by UPC, qualified as discontinued operations. For the years ended December 31, 2025 and 2024, we have consolidated our Operating and Underwriting Expenses and General and Administrative Expenses lines within our Consolidated Statements of Comprehensive Income into the General and Administrative Expenses line. This was done in an effort to align more closely with our peer group for comparability. Accordingly, we have recast our Consolidated Statements of Comprehensive Income for the year ended December 31, 2023 to align with this format. We have also added a new note to our consolidated financial statements, N ote 3, Disaggregation of Relevant Expense Captions, to provide the users of our financial statements with enhanced insight into this expense line. In addition, for the year ended December 31, 2025, we have consolidated our Payments outstanding line within our Consolidated Balance Sheets into the Other Liabilities line. This was done based on the size of our Payments outstanding over the last three years. Accordingly, we have recast our Consolidated Balance Sheets for the year ended December 31, 2024 to align with this format.

Organization, Consolidation and Presentation

12 Months Ended

Dec. 31, 2025

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Organization, Consolidation and Presentation

ORGANIZATION, CONSOLIDATION AND PRESENTATION

(a)

Business

American Coastal Insurance Corporation (referred to in this document as we, our, us, the Company or ACIC) is a property and casualty insurance holding company that sources, writes and services residential commercial property insurance policies using a network of agents and one wholly owned insurance subsidiary, American Coastal Insurance Company (AmCoastal), acquired via merger on April 3, 2017. On July 10, 2023, we changed our corporate name from United Insurance Holdings Corp. to American Coastal Insurance Corporation. The Company also previously wrote insurance through Interboro Insurance Company (IIC); however, on April 1, 2025, the Company completed the sale of IIC. The details of this transaction are described below.

The Company's other subsidiaries include Skyway Underwriters, LLC, a managing general agent that provides policy and claims administration, underwriting, technological and distribution services to the Company's insurance company; AmCo Holding Company, LLC (AmCo), which is a holding company subsidiary that consolidates its respective insurance company; BlueLine Cayman Holdings (BlueLine), which reinsures portfolios of excess and surplus policies; and Shoreline Re, which provides a portion of the reinsurance protection purchased by the Company's insurance subsidiary where management deems prudent. The Company also has several subsidiaries in run-off including United Insurance Management, L.C. (UIM), a managing general agent; Skyway Claims Services, LLC (SCS), which previously provided claims adjusting services to the Company's insurance companies; Skyway Reinsurance Services, LLC, which previously provided reinsurance brokerage services for the Company's insurance companies; and Skyway Legal Services, LLC (SLS), which previously provided claims litigation services to the Company's insurance companies.

We write commercial residential property insurance in Florida. On February 27, 2023, our former insurance subsidiary that wrote personal residential business in six states, United Property & Casualty Insurance Company (UPC), was placed into receivership with the Florida Department of Financial Services (DFS), which divested our ownership of UPC. The events leading to receivership and results of this subsidiary, now included within discontinued operations, are discussed in Note 4 below.

On May 9, 2024, we entered into a Stock Purchase Agreement (the "Sale Agreement") with Forza Insurance Holdings, LLC (Forza) in which we agreed to sell and Forza agreed to acquire 100% of the issued and outstanding stock of IIC. Forza’s application to acquire IIC was approved by the New York Department of Financial Services (NYDFS) on February 13, 2025 and the sale closed on April 1, 2025. The aggregate purchase price for the shares was equal to IIC's shareholders' equity under U.S. generally accepted accounting principles (GAAP) on the closing date. IIC results of operations and assets and liabilities are captured within discontinued operations and are discussed in Note 4 of the Notes to Consolidated Financial Statements below.

As a result of the Sale Agreement described above, IIC is presented as discontinued operations. The remaining activity captured within continuing operations supports only our commercial residential insurance offerings. Given this fact pattern, we conduct our operations under one operating segment, which consists of our commercial lines business. Further information regarding this segment can be seen in Not e 2(j) below.

(b)

Consolidation and Presentation

We prepare our consolidated financial statements in conformity with U.S. generally accepted accounting principles (GAAP). While preparing our consolidated financial statements, we make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the consolidated financial statements, as well as reported amounts of revenues and expenses during the reporting period. Accordingly, actual results could differ from those estimates. Reported amounts that require us to make extensive use of estimates include our reserves for unpaid losses and loss adjustment expenses, investments and goodwill. Except for the captions on our Consolidated Balance Sheets and Consolidated Statements of Comprehensive Income (Loss), we generally use the term loss(es) to collectively refer to both loss and loss adjustment expenses.

We include all our subsidiaries in our consolidated financial statements, eliminating intercompany balances and transactions during consolidation. As described in Note 2, our former subsidiaries, IIC and UPC, and activities related directly to supporting the business conducted by UPC, qualified as discontinued operations.

For the years ended December 31, 2025 and 2024, we have consolidated our Operating and Underwriting Expenses and General and Administrative Expenses lines within our Consolidated Statements of Comprehensive Income into the General and Administrative Expenses line. This was done in an effort to align more closely with our peer group for comparability. Accordingly, we have recast our Consolidated Statements of Comprehensive Income for the year ended December 31, 2023 to align with this format. We have also added a new note to our consolidated financial statements, N ote 3, Disaggregation of Relevant Expense Captions, to provide the users of our financial statements with enhanced insight into this expense line.

In addition, for the year ended December 31, 2025, we have consolidated our Payments outstanding line within our Consolidated Balance Sheets into the Other Liabilities line. This was done based on the size of our Payments outstanding over the last three years. Accordingly, we have recast our Consolidated Balance Sheets for the year ended December 31, 2024 to align with this format.