<SEC-DOCUMENT>0000874501-23-000042.txt : 20230302
<SEC-HEADER>0000874501-23-000042.hdr.sgml : 20230302
<ACCEPTANCE-DATETIME>20230302162043
ACCESSION NUMBER:		0000874501-23-000042
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20230228
FILED AS OF DATE:		20230302
DATE AS OF CHANGE:		20230302

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			McGinnis Daniel
		CENTRAL INDEX KEY:			0001900989

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-10777
		FILM NUMBER:		23699255

	MAIL ADDRESS:	
		STREET 1:		C/O AMBAC FINANCIAL GROUP, INC.
		STREET 2:		ONE WORLD TRADE CENTER, 41ST FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10007

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			AMBAC FINANCIAL GROUP INC
		CENTRAL INDEX KEY:			0000874501
		STANDARD INDUSTRIAL CLASSIFICATION:	SURETY INSURANCE [6351]
		IRS NUMBER:				133621676
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		ONE WORLD TRADE CENTER
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10007
		BUSINESS PHONE:		2126587470

	MAIL ADDRESS:	
		STREET 1:		ONE WORLD TRADE CENTER
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10007

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	AMBAC INC /DE/
		DATE OF NAME CHANGE:	19930328
</SEC-HEADER>
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<TYPE>4
<SEQUENCE>1
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<DESCRIPTION>FORM 4
<TEXT>
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    <periodOfReport>2023-02-28</periodOfReport>

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    <issuer>
        <issuerCik>0000874501</issuerCik>
        <issuerName>AMBAC FINANCIAL GROUP INC</issuerName>
        <issuerTradingSymbol>AMBC</issuerTradingSymbol>
    </issuer>

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            <rptOwnerCik>0001900989</rptOwnerCik>
            <rptOwnerName>McGinnis Daniel</rptOwnerName>
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        <reportingOwnerAddress>
            <rptOwnerStreet1>AMBAC FINANCIAL GROUP, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>ONE WORLD TRADE CENTER, 41ST FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK,</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10007</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Sr. MD &amp; COO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

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        </nonDerivativeTransaction>
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    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F4"/>
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            <transactionDate>
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                    <footnoteId id="F1"/>
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            <expirationDate>
                <footnoteId id="F1"/>
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            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>6735.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
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                <sharesOwnedFollowingTransaction>
                    <value>15320</value>
                </sharesOwnedFollowingTransaction>
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            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
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        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
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                    <value>330</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
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                <transactionAcquiredDisposedCode>
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            <expirationDate>
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                <underlyingSecurityTitle>
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                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>330.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
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                <sharesOwnedFollowingTransaction>
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                </sharesOwnedFollowingTransaction>
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                    <value>2532</value>
                    <footnoteId id="F5"/>
                </transactionShares>
                <transactionPricePerShare>
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                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
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                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
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        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Deferred Share Units</value>
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            </conversionOrExercisePrice>
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                    <value>2532</value>
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    </derivativeTable>

    <footnotes>
        <footnote id="F1">Represents the aggregate amount of restricted stock units (&quot;RSUs&quot;) that were converted into shares of common stock of Ambac Financial Group, Inc. (the &quot;Company&quot;) upon settlement of a portion of the reporting person's 2022 sign-on bonus.</footnote>
        <footnote id="F2">Represents the aggregate amount of RSUs that were converted into shares of common stock and withheld by the Company to satisfy certain tax withholding obligations.</footnote>
        <footnote id="F3">Represents the aggregate amount of RSUs that were converted into shares of common stock of the Company upon settlement of a portion of the reporting person's 2022 Long Term Incentive Plan award.</footnote>
        <footnote id="F4">Each RSU represents a contingent right to receive one share of Ambac Financial Group, Inc. (the &quot;Company&quot;) common stock.</footnote>
        <footnote id="F5">Represents the aggregate amount of RSUs that were converted into an equivalent number of Deferred Share Units (&quot;DSUs&quot;) pursuant to the Company's Executive Stock Deferral Plan, which was designed to enable participants to elect to defer the settlement and income taxation of RSU and Performance Stock Unit awards in accordance with Section 409A of the Internal Revenue Code of 1986, as amended.</footnote>
        <footnote id="F6">Represents the aggregate amount of RSUs that were converted into DSUs of the Company upon settlement of a portion of the reporting person's 2022 Long Term Incentive Plan award.</footnote>
        <footnote id="F7">Each DSU represents a contingent right to receive one share of common stock of the Company.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>William White, attorney in fact</signatureName>
        <signatureDate>2023-03-01</signatureDate>
    </ownerSignature>
</ownershipDocument>
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</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
