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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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MIC-Info: RSA-MD5,RSA,
 DtW+JBifM/JUl7bNf75ghrMmaEmV/n+L+u79j6msSS/ABjC80WY1hLCtHzSmtP3d
 vYoiGDkahEgGLRRJqtlq9w==

<SEC-DOCUMENT>0000926044-04-000600.txt : 20041124
<SEC-HEADER>0000926044-04-000600.hdr.sgml : 20041124
<ACCEPTANCE-DATETIME>20041124150148
ACCESSION NUMBER:		0000926044-04-000600
CONFORMED SUBMISSION TYPE:	4/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20041122
FILED AS OF DATE:		20041124
DATE AS OF CHANGE:		20041124

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			PETERS DALE A
		CENTRAL INDEX KEY:			0001185843

	FILING VALUES:
		FORM TYPE:		4/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-14209
		FILM NUMBER:		041166945

	BUSINESS ADDRESS:	
		STREET 1:		311 WOODWORTH AVE
		CITY:			ALMA
		STATE:			MI
		ZIP:			48801

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			FIRSTBANK CORP
		CENTRAL INDEX KEY:			0000778972
		STANDARD INDUSTRIAL CLASSIFICATION:	STATE COMMERCIAL BANKS [6022]
		IRS NUMBER:				382633910
		STATE OF INCORPORATION:			MI
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		311 WOODWORTH AVE
		STREET 2:		PO BOX 1029
		CITY:			ALMA
		STATE:			MI
		ZIP:			48801
		BUSINESS PHONE:		5174633131

	MAIL ADDRESS:	
		STREET 1:		311 WOODWORTH AVE
		CITY:			ALMA
		STATE:			MI
		ZIP:			48801
</SEC-HEADER>
<DOCUMENT>
<TYPE>4/A
<SEQUENCE>1
<FILENAME>peters4a_112204ex.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2004-11-22</periodOfReport>

    <dateOfOriginalSubmission>2004-11-24</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000778972</issuerCik>
        <issuerName>FIRSTBANK CORP</issuerName>
        <issuerTradingSymbol>FBMI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001185843</rptOwnerCik>
            <rptOwnerName>PETERS DALE A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>311 WOODWORTH AVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>ALMA</rptOwnerCity>
            <rptOwnerState>MI</rptOwnerState>
            <rptOwnerZipCode>48801</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Vice President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Employee Stock Option (Right-to-buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>28.32</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2004-11-22</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1250</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2014-11-22</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1250</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1250</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Vesting Schedule: 1 year 20%, 2 year 40%, 3 year 60%, 4 year 80%, 5 year 100%</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Donald Johnson, Attorney in fact</signatureName>
        <signatureDate>2004-11-24</signatureDate>
    </ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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