<SEC-DOCUMENT>0001127602-21-001176.txt : 20210107
<SEC-HEADER>0001127602-21-001176.hdr.sgml : 20210107
<ACCEPTANCE-DATETIME>20210107151216
ACCESSION NUMBER:		0001127602-21-001176
CONFORMED SUBMISSION TYPE:	4/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210104
FILED AS OF DATE:		20210107
DATE AS OF CHANGE:		20210107

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Keefe Michael C
		CENTRAL INDEX KEY:			0001396018

	FILING VALUES:
		FORM TYPE:		4/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34481
		FILM NUMBER:		21514035

	MAIL ADDRESS:	
		STREET 1:		C/O MISTRAS GROUP
		STREET 2:		195 CLARKSVILLE ROAD
		CITY:			PRINCETON JUNCTION
		STATE:			NJ
		ZIP:			08550

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Mistras Group, Inc.
		CENTRAL INDEX KEY:			0001436126
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-ENGINEERING SERVICES [8711]
		IRS NUMBER:				223341267
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		195 CLARKSVILLE ROAD
		CITY:			PRINCETON JUNCTION
		STATE:			NJ
		ZIP:			08550
		BUSINESS PHONE:		609-716-4000

	MAIL ADDRESS:	
		STREET 1:		195 CLARKSVILLE ROAD
		CITY:			PRINCETON JUNCTION
		STATE:			NJ
		ZIP:			08550
</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>2021-01-04</periodOfReport>

    <dateOfOriginalSubmission>2021-01-05</dateOfOriginalSubmission>

    <issuer>
        <issuerCik>0001436126</issuerCik>
        <issuerName>Mistras Group, Inc.</issuerName>
        <issuerTradingSymbol>MG</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001396018</rptOwnerCik>
            <rptOwnerName>Keefe Michael C</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MISTRAS GROUP</rptOwnerStreet1>
            <rptOwnerStreet2>195 CLARKSVILLE ROAD</rptOwnerStreet2>
            <rptOwnerCity>PRINCETON JUNCTION</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>08550</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isOfficer>1</isOfficer>
            <officerTitle>EVP, General Counsel</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2021-01-04</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>32</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>7.76</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>41070</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Represents shares withheld for payment of tax liability as a result of the vesting of restricted stock units.  This filing is to correct a clerical error in the original filing regarding the number of shares withheld.  The original filing disclosed 817  shares were withheld but 849 shares were actually withheld.  Accordingly, this amendment reports the 32 share difference.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Michael C. Keefe</signatureName>
        <signatureDate>2021-01-07</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
