<SEC-DOCUMENT>0001288257-18-000020.txt : 20180626
<SEC-HEADER>0001288257-18-000020.hdr.sgml : 20180626
<ACCEPTANCE-DATETIME>20180626172427
ACCESSION NUMBER:		0001288257-18-000020
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20180622
FILED AS OF DATE:		20180626
DATE AS OF CHANGE:		20180626

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			HOGAN JOSEPH M
		CENTRAL INDEX KEY:			0001233163

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-32259
		FILM NUMBER:		18920106

	MAIL ADDRESS:	
		STREET 1:		C/O ALIGN TECHNOLOGY, INC.
		STREET 2:		2560 ORCHARD PARKWAY
		CITY:			SAN JOSE
		STATE:			CA
		ZIP:			95131

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ALIGN TECHNOLOGY INC
		CENTRAL INDEX KEY:			0001097149
		STANDARD INDUSTRIAL CLASSIFICATION:	ORTHOPEDIC, PROSTHETIC & SURGICAL APPLIANCES & SUPPLIES [3842]
		IRS NUMBER:				943267295
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		2820 ORCHARD PARKWAY
		CITY:			SAN JOSE
		STATE:			CA
		ZIP:			95134
		BUSINESS PHONE:		408-470-1000

	MAIL ADDRESS:	
		STREET 1:		2820 ORCHARD PARKWAY
		CITY:			SAN JOSE
		STATE:			CA
		ZIP:			95134
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-06-22</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001097149</issuerCik>
        <issuerName>ALIGN TECHNOLOGY INC</issuerName>
        <issuerTradingSymbol>ALGN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001233163</rptOwnerCik>
            <rptOwnerName>HOGAN JOSEPH M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ALIGN TECHNOLOGY, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>2560 ORCHARD PARKWAY</rptOwnerStreet2>
            <rptOwnerCity>SAN JOSE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95131</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President and CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Market Stock Unit</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.0001</value>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2018-06-22</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>129300</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>129300</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>129300</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Represents par value of ALGN common stock.</footnote>
        <footnote id="F2">Represents the maximum number of shares which may be issued under the market stock unit granted on June 22, 2018.  All of the shares which may be issued under the market stock unit will vest on the last day of the third year of the Performance Period (as defined in the market stock unit agreement).</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Roger E George Atty-in-Fact for Joseph M. Hogan</signatureName>
        <signatureDate>2018-06-26</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
