-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 RUq+F2BSzMsoRuSj1HGth78ivKjMl17oKkMkrzeccdlENR0Z9dgigd9WBpBAHxvb
 4KaJeONB37l/jeCCsXYdGQ==

<SEC-DOCUMENT>0001253464-09-000015.txt : 20091230
<SEC-HEADER>0001253464-09-000015.hdr.sgml : 20091230
<ACCEPTANCE-DATETIME>20091230094827
ACCESSION NUMBER:		0001253464-09-000015
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20091229
FILED AS OF DATE:		20091230
DATE AS OF CHANGE:		20091230

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			IBERIABANK CORP
		CENTRAL INDEX KEY:			0000933141
		STANDARD INDUSTRIAL CLASSIFICATION:	STATE COMMERCIAL BANKS [6022]
		IRS NUMBER:				721280718
		STATE OF INCORPORATION:			LA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		200 WEST CONGRESS STREET
		CITY:			LAFAYETTE
		STATE:			LA
		ZIP:			70505
		BUSINESS PHONE:		3375214003

	MAIL ADDRESS:	
		STREET 1:		200 WEST CONGRESS STREET
		CITY:			LAFAYETTE
		STATE:			LA
		ZIP:			70505

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ISB FINANCIAL CORP/LA
		DATE OF NAME CHANGE:	19941123

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BYRD DARYL G
		CENTRAL INDEX KEY:			0001253458

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-25756
		FILM NUMBER:		091265082

	MAIL ADDRESS:	
		STREET 1:		200 WEST CONGRESS STREET
		CITY:			LAFAYETTE
		STATE:			LA
		ZIP:			70501
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2009-12-29</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000933141</issuerCik>
        <issuerName>IBERIABANK CORP</issuerName>
        <issuerTradingSymbol>IBKC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001253458</rptOwnerCik>
            <rptOwnerName>BYRD DARYL G</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>200 WEST CONGRESS STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>LAFAYETTE</rptOwnerCity>
            <rptOwnerState>LA</rptOwnerState>
            <rptOwnerZipCode>70501</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>PRESIDENT, CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>COMMON STOCK</value>
            </securityTitle>
            <transactionDate>
                <value>2009-12-29</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>10000</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>54.43</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>139042</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>COMMON STOCK</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>7370</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>BY 401(K)</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>COMMON STOCK</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1875</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>BY CHILD</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>STOCK OPTIONS</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>54.43</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2009-12-29</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>27500</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>54.43</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2010-12-29</value>
            </exerciseDate>
            <expirationDate>
                <value>2019-12-29</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>COMMON STOCK</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>27500</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>211503</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">GRANTS OF RESTRICTED STOCK AWARDED VIA ISSUER'S 2008 STOCK INCENTIVE PLAN, WILL VEST EQUALLY OVER A 5-YEAR PERIOD COMMENCING WITH THE FIRST ANNIVERSARY OF THE DATE OF THE GRANTS.</footnote>
        <footnote id="F2">STOCK OPTIONS, AWARDED VIA ISSUER'S 2005 STOCK INCENTIVE PLAN, WILL VEST OVER A 5-YEAR PERIOD COMMENCING ON THE FIRST ANNIVERSARY OF THE DATE OF GRANT AT ONE FIFTH PER YEAR.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>DARYL G. BYRD</signatureName>
        <signatureDate>2009-12-29</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----