<SEC-DOCUMENT>0001093557-19-000082.txt : 20190313
<SEC-HEADER>0001093557-19-000082.hdr.sgml : 20190313
<ACCEPTANCE-DATETIME>20190313190102
ACCESSION NUMBER:		0001093557-19-000082
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20190312
FILED AS OF DATE:		20190313
DATE AS OF CHANGE:		20190313

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MOY JEFFREY
		CENTRAL INDEX KEY:			0001446422

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-51222
		FILM NUMBER:		19679412

	MAIL ADDRESS:	
		STREET 1:		C/O DEXCOM INC.
		STREET 2:		6340 SEQUENCE DRIVE
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92121

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			DEXCOM INC
		CENTRAL INDEX KEY:			0001093557
		STANDARD INDUSTRIAL CLASSIFICATION:	SURGICAL & MEDICAL INSTRUMENTS & APPARATUS [3841]
		IRS NUMBER:				330857544
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		6340 SEQUENCE DRIVE
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92121
		BUSINESS PHONE:		8582000200

	MAIL ADDRESS:	
		STREET 1:		6340 SEQUENCE DRIVE
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92121
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgardoc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
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    <periodOfReport>2019-03-12</periodOfReport>

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    <issuer>
        <issuerCik>0001093557</issuerCik>
        <issuerName>DEXCOM INC</issuerName>
        <issuerTradingSymbol>DXCM</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001446422</rptOwnerCik>
            <rptOwnerName>MOY JEFFREY</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>6340 SEQUENCE DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SAN DIEGO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92121</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>SVP Operations</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

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                <value>Common Stock</value>
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                <equitySwapInvolved>0</equitySwapInvolved>
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        </nonDerivativeTransaction>
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            <securityTitle>
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                    <value>1936</value>
                    <footnoteId id="F4"/>
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                <transactionPricePerShare>
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                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
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            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2019-03-12</value>
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                    <value>5001</value>
                    <footnoteId id="F4"/>
                </transactionShares>
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                    <value>142.7922</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
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                </transactionAcquiredDisposedCode>
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            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>28952</value>
                    <footnoteId id="F3"/>
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                <directOrIndirectOwnership>
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                <natureOfOwnership>
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            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
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                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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                    <value>1594</value>
                    <footnoteId id="F4"/>
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                    <value>142.7922</value>
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                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
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    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Shares were transferred from direct ownership to ownership under the Moy Family Trust upon vesting of previously awarded restricted stock units.</footnote>
        <footnote id="F2">Included in this number are 39,070 unvested restricted stock units, 11,714 of which were granted on March 8, 2019 and shall vest through March 8, 2022, 20,062 of which were granted on March 8, 2018 and shall vest through March 8, 2021 and 7,294 of which were granted on March 8, 2017 and shall vest through March 8, 2020.</footnote>
        <footnote id="F3">Shares are held by the Moy Family Trust U/A/D 12/09/2013, with respect to which the reporting person is a trustee.</footnote>
        <footnote id="F4">Represents the number of shares required to be sold by the reporting person to cover tax withholding obligations in connection with the vesting of RSUs. This sale is mandated by the Issuer's election under its equity incentive plans to require the satisfaction of tax withholding obligations to be funded by a &quot;sell to cover&quot; transaction and does not represent a discretionary trade by the reporting person.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>By: Timothy O'Brien For: Jeffrey Moy</signatureName>
        <signatureDate>2019-03-13</signatureDate>
    </ownerSignature>
</ownershipDocument>
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</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
