-----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,
 RrabqtpeCpdeu1N9CvWa75kxfIQCnqweYikBfr9IxBEzii8m4aKAG8E9rBYmb9Ur
 9/Gv152Cxk3BabCAe4zybQ==

<SEC-DOCUMENT>0000916863-08-000146.txt : 20080324
<SEC-HEADER>0000916863-08-000146.hdr.sgml : 20080324
<ACCEPTANCE-DATETIME>20080324154738
ACCESSION NUMBER:		0000916863-08-000146
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080320
FILED AS OF DATE:		20080324
DATE AS OF CHANGE:		20080324

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BAILEY KEITH E
		CENTRAL INDEX KEY:			0001216042

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-11337
		FILM NUMBER:		08707081

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		9185738889

	MAIL ADDRESS:	
		STREET 1:		6685 S EVANSTON CIRCLE
		CITY:			TULSA
		STATE:			OK
		ZIP:			74136

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			INTEGRYS ENERGY GROUP, INC.
		CENTRAL INDEX KEY:			0000916863
		STANDARD INDUSTRIAL CLASSIFICATION:	ELECTRIC & OTHER SERVICES COMBINED [4931]
		IRS NUMBER:				391775292
		STATE OF INCORPORATION:			WI
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		130 EAST RANDOLPH DRIVE
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60601
		BUSINESS PHONE:		800-699-1269

	MAIL ADDRESS:	
		STREET 1:		130 EAST RANDOLPH DRIVE
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60601

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Integrys Energy Group, Inc.
		DATE OF NAME CHANGE:	20070222

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	WPS RESOURCES CORP
		DATE OF NAME CHANGE:	19940103
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgardoc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-03-20</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000916863</issuerCik>
        <issuerName>INTEGRYS ENERGY GROUP, INC.</issuerName>
        <issuerTradingSymbol>TEG</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001216042</rptOwnerCik>
            <rptOwnerName>BAILEY KEITH E</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>130 E. RANDOLPH DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>CHICAGO</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60601</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>7302.5</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Deferred Stock Unit</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2008-03-20</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>30.7823</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>45.55</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>30.7823</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2123.526</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">These deferred stock units convert to common stock on a one-for-one basis.</footnote>
        <footnote id="F2">Unless the participant has selected a later commencement date, distribution of stock and equivalents will commence within 60 days following the end of the calendar year in which occurs the participant's retirement or termination of service.</footnote>
        <footnote id="F3">Unless the participant has selected a later commencement date, distribution of stock and equivalents will commence within 60 days following the end of the calendar year in which occurs the participant's retirement or termination of service.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>By: Barth J. Wolf, as Power of Attorney  For: Mr. Bailey</signatureName>
        <signatureDate>2008-03-24</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----