Background and Business Description	12 Months Ended
Dec. 31, 2024
Accounting Policies [Abstract]
Background and Business Description	1. BACKGROUND AND BUSINESS DESCRIPTION Ambac Financial Group, Inc. (“AFG”), headquartered in New York City, is a financial services holding company incorporated in the state of Delaware on April 29, 1991. References to “Ambac,” the “Company,” “we,” “our,” and “us” are to AFG and its subsidiaries, as the context requires. Ambac's business operations include: •Insurance Distribution — Ambac's specialty property and casualty ("P&C") insurance distribution business includes Managing General Agents and Underwriters (collectively "MGAs" or "MGA/Us"), an insurance broker, and other distribution and underwriting businesses. Insurance Distribution includes Beat Capital Partners Limited ("Beat", which was acquired on July 31, 2024). At December 31, 2024, Ambac's insurance distribution platform operates in the following lines of business: accident & health, specialty auto, other professional, marine & energy, niche specialty risks, property, reinsurance, professional D&O and other specialty lines. •Specialty Property and Casualty Insurance — Ambac's Specialty Property and Casualty Insurance program business includes four admitted carriers and an excess and surplus lines (“E&S” or “nonadmitted”) insurer (collectively, “Everspan”). Everspan carriers have an A.M. Best rating of 'A-' (Excellent) which was affirmed on June 13, 2024. The Company reports these two business operations as segments; see Note 3. Segment Information for further information. Ambac's financial guarantee business, which is being reported as a discontinued operation due to its pending sale, includes the activities of Ambac Assurance Corporation ("AAC") and its wholly owned subsidiaries, including Ambac Assurance UK Limited (“Ambac UK”) and Ambac Financial Services LLC ("AFS"). Both AAC and Ambac UK have financial guarantee insurance portfolios that have been in runoff since 2008. AFS provided interest rate derivatives to financial guarantee customers and used derivatives to hedge interest rate risk in AAC's insurance and investment portfolios. See Note 5. Discontinued Operation for information related to the pending sale of AAC. Limitations on Voting and Transfer of Common Stock AFG’s Amended and Restated Certificate of Incorporation limits voting and transfer rights of stockholders in significant ways. Article IV contains voting restrictions applicable to any person owning at least 10% of AFG's common stock so that such person (including any group consisting of such person and any other person with whom such person or any affiliate or associate of such person has any agreement, contract, arrangement or understanding with respect to acquiring, voting, holding or disposing of AFG’s common stock) shall not be entitled to cast votes in excess of one vote less than 10% of the votes entitled to be cast by all common stock holders, except as otherwise approved by the insurance commissioners of the states of domicile of the insurance companies controlled by AFG. Article XII contains substantial restrictions on the ability to transfer AFG’s common stock. In order to preserve certain tax benefits, subject to limited exceptions, any attempted transfer of common stock shall be prohibited and void to the extent that, as a result of such transfer (or any series of transfers of which such transfer is a part), either (i) any person or group of persons shall become a holder of 5% or more of AFG’s common stock or (ii) the percentage stock ownership interest in AFG of any holder of 5% or more of AFG’s common stock shall be increased (a “Prohibited Transfer”). These restrictions shall not apply to an attempted transfer if the transferor or the transferee obtains the written approval of AFG’s Board of Directors to such transfer. A purported transferee of a Prohibited Transfer shall not be recognized as a stockholder of AFG for any purpose whatsoever in respect of the securities which are the subject of the Prohibited Transfer (the “Excess Securities”). Until the Excess Securities are acquired by another person in a transfer that is not a Prohibited Transfer, the purported transferee of a Prohibited Transfer shall not be entitled with respect to such Excess Securities to any rights of stockholders of AFG, including, without limitation, the right to vote such Excess Securities and to receive dividends or distributions, whether liquidating or otherwise, in respect thereof, if any. Once the Excess Securities have been acquired in a transfer that is not a Prohibited Transfer, the securities shall cease to be Excess Securities. If the Board determines that a transfer of securities constitutes a Prohibited Transfer then, upon written demand by AFG, the purported transferee shall transfer or cause to be transferred any certificate or other evidence of ownership of the Excess Securities within the purported transferee’s possession or control, together with any distributions paid by AFG with respect to such Excess Securities, to an agent designated by AFG. Such agent shall thereafter sell such Excess Securities and the proceeds of such sale shall be distributed as set forth in the Amended and Restated Certificate of Incorporation. If the purported transferee of a Prohibited Transfer has resold the Excess Securities before receiving such demand, such person shall be deemed to have sold the Excess Securities for AFG’s agent and shall be required to transfer to such agent the proceeds of such sale, which shall be distributed as set forth in the Amended and Restated Certificate of Incorporation.

Background and Business Description

12 Months Ended

Dec. 31, 2024

1. BACKGROUND AND BUSINESS DESCRIPTION

Ambac Financial Group, Inc. (“AFG”), headquartered in New York City, is a financial services holding company incorporated in the state of Delaware on April 29, 1991. References to “Ambac,” the “Company,” “we,” “our,” and “us” are to AFG and its subsidiaries, as the context requires. Ambac's business operations include:

•Insurance Distribution — Ambac's specialty property and casualty ("P&C") insurance distribution business includes Managing General Agents and Underwriters (collectively "MGAs" or "MGA/Us"), an insurance broker, and other distribution and underwriting businesses. Insurance Distribution includes Beat Capital Partners Limited ("Beat", which was acquired on July 31, 2024). At December 31, 2024, Ambac's insurance distribution platform operates in the following lines of business: accident & health, specialty auto, other professional, marine & energy, niche specialty risks, property, reinsurance, professional D&O and other specialty lines.

•Specialty Property and Casualty Insurance — Ambac's Specialty Property and Casualty Insurance program business includes four admitted carriers and an excess and surplus lines (“E&S” or “nonadmitted”) insurer (collectively, “Everspan”). Everspan carriers have an A.M. Best rating of 'A-' (Excellent) which was affirmed on June 13, 2024.

The Company reports these two business operations as segments; see Note 3. Segment Information for further information.

Ambac's financial guarantee business, which is being reported as a discontinued operation due to its pending sale, includes the activities of Ambac Assurance Corporation ("AAC") and its wholly owned subsidiaries, including Ambac Assurance UK Limited (“Ambac UK”) and Ambac Financial Services LLC ("AFS"). Both AAC and Ambac UK have financial guarantee insurance portfolios that have been in runoff since 2008. AFS provided interest rate derivatives to financial guarantee customers and used derivatives to hedge interest rate risk in AAC's insurance and investment portfolios. See Note 5. Discontinued Operation for information related to the pending sale of AAC.

Limitations on Voting and Transfer of Common Stock

AFG’s Amended and Restated Certificate of Incorporation limits voting and transfer rights of stockholders in significant ways. Article IV contains voting restrictions applicable to any person owning at least 10% of AFG's common stock so that such person (including any group consisting of such person and any other person with whom such person or any affiliate or associate of such person has any agreement, contract, arrangement or understanding with respect to acquiring, voting, holding or disposing of AFG’s common stock) shall not be entitled to cast votes in excess of one vote less than 10% of the votes entitled to be cast by all common stock holders, except as

otherwise approved by the insurance commissioners of the states of domicile of the insurance companies controlled by AFG. Article XII contains substantial restrictions on the ability to transfer AFG’s common stock. In order to preserve certain tax benefits, subject to limited exceptions, any attempted transfer of common stock shall be prohibited and void to the extent that, as a result of such transfer (or any series of transfers of which such transfer is a part), either (i) any person or group of persons shall become a holder of 5% or more of AFG’s common stock or (ii) the percentage stock ownership interest in AFG of any holder of 5% or more of AFG’s common stock shall be increased (a “Prohibited Transfer”). These restrictions shall not apply to an attempted transfer if the transferor or the transferee obtains the written approval of AFG’s Board of Directors to such transfer. A purported transferee of a Prohibited Transfer shall not be recognized as a stockholder of AFG for any purpose whatsoever in respect of the securities which are the subject of the Prohibited Transfer (the “Excess Securities”). Until the Excess Securities are acquired by another person in a transfer that is not a Prohibited Transfer, the purported transferee of a Prohibited Transfer shall not be entitled with respect to such Excess Securities to any rights of stockholders of AFG, including, without limitation, the right to vote such Excess Securities and to receive dividends or distributions, whether liquidating or otherwise, in respect thereof, if any. Once the Excess Securities have been acquired in a transfer that is not a Prohibited Transfer, the securities shall cease to be Excess Securities. If the Board determines that a transfer of securities constitutes a Prohibited Transfer then, upon written demand by AFG, the purported transferee shall transfer or cause to be transferred any certificate or other evidence of ownership of the Excess Securities within the purported transferee’s possession or control, together with any distributions paid by AFG with respect to such Excess Securities, to an agent designated by AFG. Such agent shall thereafter sell such Excess Securities and the proceeds of such sale shall be distributed as set forth in the Amended and Restated Certificate of Incorporation. If the purported transferee of a Prohibited Transfer has resold the Excess Securities before receiving such demand, such person shall be deemed to have sold the Excess Securities for AFG’s agent and shall be required to transfer to such agent the proceeds of such sale, which shall be distributed as set forth in the Amended and Restated Certificate of Incorporation.