<SEC-DOCUMENT>0001690001-25-000017.txt : 20250214
<SEC-HEADER>0001690001-25-000017.hdr.sgml : 20250214
<ACCEPTANCE-DATETIME>20250214102347
ACCESSION NUMBER:		0001690001-25-000017
CONFORMED SUBMISSION TYPE:	5
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20241231
FILED AS OF DATE:		20250214
DATE AS OF CHANGE:		20250214

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Halliday Sarah A
		CENTRAL INDEX KEY:			0001707868
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		5
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-14703
		FILM NUMBER:		25624492

	MAIL ADDRESS:	
		STREET 1:		52 SOUTH BROAD STREET
		CITY:			NORWICH
		STATE:			NY
		ZIP:			13815

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			NBT BANCORP INC
		CENTRAL INDEX KEY:			0000790359
		STANDARD INDUSTRIAL CLASSIFICATION:	NATIONAL COMMERCIAL BANKS [6021]
		ORGANIZATION NAME:           	02 Finance
		IRS NUMBER:				161268674
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		52 S BROAD ST
		CITY:			NORWICH
		STATE:			NY
		ZIP:			13815
		BUSINESS PHONE:		6073372265

	MAIL ADDRESS:	
		STREET 1:		52 S. BROAD STREET
		CITY:			NORWICH
		STATE:			NY
		ZIP:			13815
</SEC-HEADER>
<DOCUMENT>
<TYPE>5
<SEQUENCE>1
<FILENAME>edgardoc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>5</documentType>

    <periodOfReport>2024-12-31</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <form3HoldingsReported>0</form3HoldingsReported>

    <form4TransactionsReported>0</form4TransactionsReported>

    <issuer>
        <issuerCik>0000790359</issuerCik>
        <issuerName>NBT BANCORP INC</issuerName>
        <issuerTradingSymbol>NBTB</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001707868</rptOwnerCik>
            <rptOwnerName>Halliday Sarah A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>52 SOUTH BROAD STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>NORWICH</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>13815</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EVP/President Comm Banking</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>NBT Bancorp Inc. Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2024-12-31</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>327.452</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.0</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>7402.768</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>401k</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>NBT Bancorp Inc. Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>32402</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Phantom Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2024-12-31</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>163.154</value>
                    <footnoteId id="F3"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>NBT Bancorp Inc. Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>163.154</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5145.101</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Shares were purchased through payroll deferral and/or dividend reinvestment from 1/1/2024 to 12/31/2024 through NBT Bancorp Inc. 401k Plan.</footnote>
        <footnote id="F2">Each share of phantom stock is deemed invested in one share of NBT Bancorp Inc. common stock pursuant to the terms of the Deferred Compensation Plan.</footnote>
        <footnote id="F3">Shares were purchased through payroll deferral and/or dividend reinvestment from 1/1/2024 to 12/31/2024 through a NBT Bancorp Inc. deferred compensation plan.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>By: Annette L. Burns, Power of Attorney For: Sarah A. Halliday</signatureName>
        <signatureDate>2025-02-14</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
