-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 UPQFYmUaPXcy5gtGK3dQfyiOjvRpzQle9H1Sq9bjxu12A36b8Zm7ME6SoE0oHFZj
 Z6bzHB0Pw6sZU38OUz7ToA==

<SEC-DOCUMENT>0001249627-03-000001.txt : 20030930
<SEC-HEADER>0001249627-03-000001.hdr.sgml : 20030930
<ACCEPTANCE-DATETIME>20030930185809
ACCESSION NUMBER:		0001249627-03-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030919
FILED AS OF DATE:		20030930

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MARKER JAMES N
		CENTRAL INDEX KEY:			0001249627

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-22435
		FILM NUMBER:		03918737

	BUSINESS ADDRESS:	
		STREET 1:		920 MAIN STREET
		CITY:			LEWISTON
		STATE:			ID
		ZIP:			83501
		BUSINESS PHONE:		2087469610

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			FIRSTBANK CORP/ID
		CENTRAL INDEX KEY:			0001035513
		STANDARD INDUSTRIAL CLASSIFICATION:	NATIONAL COMMERCIAL BANKS [6021]
		IRS NUMBER:				841389562
		STATE OF INCORPORATION:			WA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		920 MAIN ST
		CITY:			LEWISTON
		STATE:			ID
		ZIP:			83501
		BUSINESS PHONE:		2087469610

	MAIL ADDRESS:	
		STREET 1:		920 MAIN ST
		CITY:			LEWISTON
		STATE:			ID
		ZIP:			83501
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>

<ownershipDocument>

    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2003-09-19</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001035513</issuerCik>
        <issuerName>FIRSTBANK CORP/ID</issuerName>
        <issuerTradingSymbol>FBNW</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001249627</rptOwnerCik>
            <rptOwnerName>MARKER JAMES N</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1></rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity></rptOwnerCity>
            <rptOwnerState></rptOwnerState>
            <rptOwnerZipCode></rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>

        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2003-09-19</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>X</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>100</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>15.81</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>7751</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>

    </nonDerivativeTable>



    <ownerSignature>
        <signatureName>James N. Marker</signatureName>
        <signatureDate>2003-09-30</signatureDate>
    </ownerSignature>

</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----