<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2019-05-09</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000739421</issuerCik>
        <issuerName>CITIZENS FINANCIAL SERVICES INC</issuerName>
        <issuerTradingSymbol>CZFS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001234118</rptOwnerCik>
            <rptOwnerName>RICHARDS DAVID Z JR</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>209 TWIGS LANE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>STATE COLLEGE</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>16801</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EXECUTIVE VICE PRESIDENT</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>COMMON CLASS</value>
            </securityTitle>
            <transactionDate>
                <value>2019-05-09</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>195</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>890.0766</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <remarks>STOCK AWARDS GRANTED PURSUANT TO THE CITIZENS FINANCIAL SERVICES, INC. 2016 EQUITY INCENTIVE PLAN VEST IN THREE EQUAL ANNUAL INSTALLMENTS COMMENCING MAY 9, 2020.</remarks>

    <ownerSignature>
        <signatureName>GINA MARIE BOOR FOR DAVID Z. RICHARDS, JR. UNDER POWER OF ATTORNEY DATED 12/08/2017</signatureName>
        <signatureDate>2019-05-10</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0306
4
2019-05-09
0
0000739421
CITIZENS FINANCIAL SERVICES INC
CZFS
0001234118
RICHARDS DAVID Z JR
209 TWIGS LANE
STATE COLLEGE
PA
16801
1
1
0
0
EXECUTIVE VICE PRESIDENT
COMMON CLASS
2019-05-09
4
A
0
195
0
A
890.0766
D
STOCK AWARDS GRANTED PURSUANT TO THE CITIZENS FINANCIAL SERVICES, INC. 2016 EQUITY INCENTIVE PLAN VEST IN THREE EQUAL ANNUAL INSTALLMENTS COMMENCING MAY 9, 2020.
GINA MARIE BOOR FOR DAVID Z. RICHARDS, JR. UNDER POWER OF ATTORNEY DATED 12/08/2017
2019-05-10