<SEC-DOCUMENT>0000876437-25-000098.txt : 20250522
<SEC-HEADER>0000876437-25-000098.hdr.sgml : 20250522
<ACCEPTANCE-DATETIME>20250522163356
ACCESSION NUMBER:		0000876437-25-000098
CONFORMED SUBMISSION TYPE:	4/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20250226
FILED AS OF DATE:		20250522
DATE AS OF CHANGE:		20250522

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Maggio Paula C
		CENTRAL INDEX KEY:			0001293826
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-10816
		FILM NUMBER:		25977686

	MAIL ADDRESS:	
		STREET 1:		C/O STRATEGIC HOTEL CAPITAL, INC.
		STREET 2:		77 WEST WACKER DRIVE, STE 4600
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60601

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MGIC INVESTMENT CORP
		CENTRAL INDEX KEY:			0000876437
		STANDARD INDUSTRIAL CLASSIFICATION:	SURETY INSURANCE [6351]
		ORGANIZATION NAME:           	02 Finance
		EIN:				391486475
		STATE OF INCORPORATION:			WI
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		250 EAST KILBOURN AVENUE
		CITY:			MILWAUKEE
		STATE:			WI
		ZIP:			53202
		BUSINESS PHONE:		4143476480

	MAIL ADDRESS:	
		STREET 1:		250 EAST KILBOURN AVENUE
		CITY:			MILWAUKEE
		STATE:			WI
		ZIP:			53202
</SEC-HEADER>
<DOCUMENT>
<TYPE>4/A
<SEQUENCE>1
<FILENAME>wk-form4a_1747946024.xml
<DESCRIPTION>FORM 4/A
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2025-02-26</periodOfReport>

    <dateOfOriginalSubmission>2025-02-27</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000876437</issuerCik>
        <issuerName>MGIC INVESTMENT CORP</issuerName>
        <issuerTradingSymbol>MTG</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001293826</rptOwnerCik>
            <rptOwnerName>Maggio Paula C</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>250 EAST KILBOURN AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MILWAUKEE</rptOwnerCity>
            <rptOwnerState>WI</rptOwnerState>
            <rptOwnerZipCode>53202</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EVP and General Counsel</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2025-02-26</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>133248</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>236601.68</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F3"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>110422</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F3"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By an individual trust</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Represents shares of Issuer common stock to be issued under a restricted stock unit award granted to the Reporting Person on February 4, 2022. The award is subject to performance-vesting restrictions based on growth in adjusted book value per share. Performance with respect to the shares reported in Column 4 has been approved by the appropriate committee of Issuer's Board. Provided continued employment, the shares will be issued to the Reporting Person on February 28, 2025.</footnote>
        <footnote id="F2">These RSUs were awarded to the reporting person pursuant to the Issuer's 2020 Omnibus Incentive Plan and no price was paid by the reporting person for them.</footnote>
        <footnote id="F3">This amended Form 4 is being filed to correct the ownership form for the non-derivative securities reported in Table I of the original Form 4.   Due to administrative error, the number of shares owned indirectly by the reporting person was understated by 23,526 and the number of shares owned directly by the reporting person was overstated by 23,526.  The total number of shares owned remains the same.  The Form 4 filed on 2/28/25 similarly understated the reporting individual's indirect ownership and overstated the reporting individual's direct ownership.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Leslie A. Schunk, Attorney-in-Fact</signatureName>
        <signatureDate>2025-05-22</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
