-----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,
 MEKRx1h4xOdE9MHEOxLBgHWFGfCVksPjSYnCcZaV1Rkk5aVaV0+7OGO1jKq7hTvU
 Nj3WWFGnvRaPk0J7XsGRmw==

<SEC-DOCUMENT>0001181431-06-001731.txt : 20060105
<SEC-HEADER>0001181431-06-001731.hdr.sgml : 20060105
<ACCEPTANCE-DATETIME>20060105151631
ACCESSION NUMBER:		0001181431-06-001731
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20060103
FILED AS OF DATE:		20060105
DATE AS OF CHANGE:		20060105

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			LANGFITT GARY B
		CENTRAL INDEX KEY:			0001279652

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	333-44497
		FILM NUMBER:		06512317

	MAIL ADDRESS:	
		STREET 1:		13001 HOLLENBERG DR
		CITY:			BRIDGETON
		STATE:			MO
		ZIP:			63044

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CASS INFORMATION SYSTEMS INC
		CENTRAL INDEX KEY:			0000708781
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-BUSINESS SERVICES, NEC [7389]
		IRS NUMBER:				431265338
		STATE OF INCORPORATION:			MO
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		13001 HOLLENBERG DR.
		CITY:			BRIDGETON
		STATE:			MO
		ZIP:			63044
		BUSINESS PHONE:		3145055500

	MAIL ADDRESS:	
		STREET 1:		13001 HOLLENBERG DR.
		CITY:			BRIDGETON
		STATE:			MO
		ZIP:			63044

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	CASS COMMERCIAL CORP
		DATE OF NAME CHANGE:	19950518
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>rrd102503.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2006-01-03</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000708781</issuerCik>
        <issuerName>CASS INFORMATION SYSTEMS INC</issuerName>
        <issuerTradingSymbol>CASS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001279652</rptOwnerCik>
            <rptOwnerName>LANGFITT GARY B</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>13001 HOLLENBERG DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BRIDGETON</rptOwnerCity>
            <rptOwnerState>MO</rptOwnerState>
            <rptOwnerZipCode>63044</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>COO Utilities</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2006-01-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>3465</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>14.217</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3806</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Employee Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>14.217</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2006-01-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>3465</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2006-01-03</value>
            </exerciseDate>
            <expirationDate>
                <value>2006-01-03</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>3465</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">In September 2005, Cass Information Systems, Inc. declared a 50% stock dividend, resulting in the reporting person's acquisition of 114 additional shares of common stock.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Gary B. Langfitt</signatureName>
        <signatureDate>2006-01-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----