<SEC-DOCUMENT>0001127602-15-029792.txt : 20151029
<SEC-HEADER>0001127602-15-029792.hdr.sgml : 20151029
<ACCEPTANCE-DATETIME>20151029175627
ACCESSION NUMBER:		0001127602-15-029792
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20151027
FILED AS OF DATE:		20151029
DATE AS OF CHANGE:		20151029

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			COMMUNITY BANK SYSTEM, INC.
		CENTRAL INDEX KEY:			0000723188
		STANDARD INDUSTRIAL CLASSIFICATION:	NATIONAL COMMERCIAL BANKS [6021]
		IRS NUMBER:				161213679
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		5790 WIDEWATERS PKWY
		CITY:			DEWITT
		STATE:			NY
		ZIP:			13214
		BUSINESS PHONE:		8007242262

	MAIL ADDRESS:	
		STREET 1:		5790 WIDEWATERS PARKWAY
		CITY:			DEWITT
		STATE:			NY
		ZIP:			13214

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	COMMUNITY BANK NA, a subsidiary of Community Bank System Inc
		DATE OF NAME CHANGE:	20130729

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	COMMUNITY BANK NA, a subsidiary of Community Bank System Inc.
		DATE OF NAME CHANGE:	20130726

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	COMMUNITY BANK SYSTEM INC
		DATE OF NAME CHANGE:	19920703

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			DICERBO NICHOLAS A
		CENTRAL INDEX KEY:			0001234449

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-13695
		FILM NUMBER:		151184836
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>form4.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2015-10-27</periodOfReport>

    <issuer>
        <issuerCik>0000723188</issuerCik>
        <issuerName>COMMUNITY BANK SYSTEM, INC.</issuerName>
        <issuerTradingSymbol>CBU</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001234449</rptOwnerCik>
            <rptOwnerName>DICERBO NICHOLAS A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>2835 WEST RIVER ROAD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>OLEAN</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>14760</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2015-10-27</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>5000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>40.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>204566.7334</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>946.922</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Spouse</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Phantom Stock (Stock Balance Plan)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F3"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>19126.34</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>19126.34</value>
                    <footnoteId id="F4"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Includes 973.03 shares, 890.624 shares and 920.548 shares acquired on April 10, 2015, July 10, 2015, and October 9, 2015, respectively, under the Community Bank System, Inc. Dividend Reinvestment Plan.</footnote>
        <footnote id="F2">Includes 7.972 shares and 7.487 shares acquired on April 10, 2015 and July 10, 2015, respectively, under the Community Bank System, Inc. Dividend Reinvestment Plan.</footnote>
        <footnote id="F3">Each phantom stock unit is the economic equivalent of one share of Community Bank System, Inc. common stock.  Phantom Stock (Stock Balance Plan) may be settled upon the later of the reporting person's attainment of age 55 or termination of service on Community Bank System, Inc.'s Board of Directors.</footnote>
        <footnote id="F4">Includes 431.5248 units and 399.8218 acquired on April 10, 2015 and July 10, 2015, respectively, pursuant to the Deferred Compensation Plan's dividend reinvestment feature.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/  Danielle M. Cima, pursuant to a Confirming Statement executed by Nicholas A. DiCerbo</signatureName>
        <signatureDate>2015-10-29</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
