<SEC-DOCUMENT>0001084991-21-000029.txt : 20210402
<SEC-HEADER>0001084991-21-000029.hdr.sgml : 20210402
<ACCEPTANCE-DATETIME>20210402132723
ACCESSION NUMBER:		0001084991-21-000029
CONFORMED SUBMISSION TYPE:	4/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210318
FILED AS OF DATE:		20210402
DATE AS OF CHANGE:		20210402

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Taylor Stephen Charles
		CENTRAL INDEX KEY:			0001316004

	FILING VALUES:
		FORM TYPE:		4/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-31398
		FILM NUMBER:		21801378

	MAIL ADDRESS:	
		STREET 1:		2911 SOUTH COUNTY ROAD 1260
		CITY:			MIDLAND
		STATE:			TX
		ZIP:			79706

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			NATURAL GAS SERVICES GROUP INC
		CENTRAL INDEX KEY:			0001084991
		STANDARD INDUSTRIAL CLASSIFICATION:	OIL, GAS FIELD SERVICES, NBC [1389]
		IRS NUMBER:				752811855
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		404 VETERANS AIRPARK LANE
		STREET 2:		SUITE 300
		CITY:			MIDLAND
		STATE:			TX
		ZIP:			79705
		BUSINESS PHONE:		(432) 262-2700

	MAIL ADDRESS:	
		STREET 1:		404 VETERANS AIRPARK LANE
		STREET 2:		SUITE 300
		CITY:			MIDLAND
		STATE:			TX
		ZIP:			79705
</SEC-HEADER>
<DOCUMENT>
<TYPE>4/A
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2021-03-18</periodOfReport>

    <dateOfOriginalSubmission>2021-03-22</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001084991</issuerCik>
        <issuerName>NATURAL GAS SERVICES GROUP INC</issuerName>
        <issuerTradingSymbol>NGS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001316004</rptOwnerCik>
            <rptOwnerName>Taylor Stephen Charles</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>404 VETERANS AIRPARK LANE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 300</rptOwnerStreet2>
            <rptOwnerCity>MIDLAND</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>79705</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Executive Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2021-03-18</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>109212</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>8.91</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>577619</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">This amendment to Form 4 is being filed to correct the number of shares granted in connection with the restricted stock award referenced in the original filing, which mistakenly reported 100,626 restricted shares.  As noted in Table I, the correct number of shares granted in the award was 109,212.  In addition, column 5 of Table has been corrected to show the revised number of shares beneficially owned following the reported transaction.  There are no other revisions to the original Form 4 as filed on March 22, 2021.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Stephen C. Taylor</signatureName>
        <signatureDate>2021-04-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
