<SEC-DOCUMENT>0001127602-16-048175.txt : 20160401
<SEC-HEADER>0001127602-16-048175.hdr.sgml : 20160401
<ACCEPTANCE-DATETIME>20160401172159
ACCESSION NUMBER:		0001127602-16-048175
CONFORMED SUBMISSION TYPE:	4/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20160114
FILED AS OF DATE:		20160401
DATE AS OF CHANGE:		20160401

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:			Getman George J
		CENTRAL INDEX KEY:			0001422188

	FILING VALUES:
		FORM TYPE:		4/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-13695
		FILM NUMBER:		161548204

	MAIL ADDRESS:	
		STREET 1:		7856 CAHILL ROAD
		CITY:			MANLIUS
		STATE:			NY
		ZIP:			13104

	FORMER NAME:	
		FORMER CONFORMED NAME:	Getman George Joseph
		DATE OF NAME CHANGE:	20071227
</SEC-HEADER>
<DOCUMENT>
<TYPE>4/A
<SEQUENCE>1
<FILENAME>form4a.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2016-01-14</periodOfReport>

    <dateOfOriginalSubmission>2016-01-19</dateOfOriginalSubmission>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001422188</rptOwnerCik>
            <rptOwnerName>Getman George J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O COMMUNITY BANK SYSTEM, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>5790 WIDEWATERS PARKWAY</rptOwnerStreet2>
            <rptOwnerCity>DEWITT</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>13214</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isOfficer>1</isOfficer>
            <officerTitle>Executive VP &amp; General Counsel</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2016-01-14</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1807.89</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>39.94</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>22968</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The reporting person is filing this amendment to increase the number of shares withheld by Community Bank System, Inc. in connection with the payment of tax liability associated with the vesting of restricted stock awards.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Danielle M. Cima, pursuant to a Confirming Statement executed by George J. Getman</signatureName>
        <signatureDate>2016-04-01</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
