    <SEC-DOCUMENT>0001104659-20-048538-index.html : 20200420
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    <ACCEPTANCE-DATETIME>20200420095629
    ACCESSION NUMBER:		0001104659-20-048538
    CONFORMED SUBMISSION TYPE:	8-K
    PUBLIC DOCUMENT COUNT:		27
    CONFORMED PERIOD OF REPORT:	20200420
    ITEM INFORMATION:		Results of Operations and Financial Condition
    ITEM INFORMATION:		Financial Statements and Exhibits
    FILED AS OF DATE:		20200420
    DATE AS OF CHANGE:		20200420

    FILER:

    	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

    	FILING VALUES:
    		FORM TYPE:		8-K
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	001-13695
    		FILM NUMBER:		20801591

    	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
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    <TYPE>8-K
    <SEQUENCE>1
    <FILENAME>tm2016286d1_8k.htm
    <DESCRIPTION>FORM 8-K
    <TEXT>
    Document 1 - file: tm2016286d1_8k.htm

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    <TYPE>EX-99.1
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    <FILENAME>tm2016286d1_ex99-1.htm
    <DESCRIPTION>EXHIBIT 99.1
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    <DESCRIPTION>GRAPHIC
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    <TYPE>JSON
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