<SEC-DOCUMENT>0001093557-18-000119.txt : 20180605
<SEC-HEADER>0001093557-18-000119.hdr.sgml : 20180605
<ACCEPTANCE-DATETIME>20180605174936
ACCESSION NUMBER:		0001093557-18-000119
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20180601
FILED AS OF DATE:		20180605
DATE AS OF CHANGE:		20180605

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Abbey Donald
		CENTRAL INDEX KEY:			0001534342

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-51222
		FILM NUMBER:		18882387

	MAIL ADDRESS:	
		STREET 1:		3750 TORREY VIEW COURT
		CITY:			SAN DIEGO
		STATE:			CA
		ZIP:			92130

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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-06-01</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001534342</rptOwnerCik>
            <rptOwnerName>Abbey Donald</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>EVP, Quality &amp; Regulatory Afrs</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2018-06-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>9011</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>88.1</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>100942</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">These shares were sold to cover the Company's tax withholding obligation that accrued in connection with the vesting of restricted stock units previously granted.</footnote>
        <footnote id="F2">Included in this number are 75,175 restricted stock units, 38,502 of which were granted on March 8, 2018 and shall vest through March 8, 2021, 18,340 of which were granted on March 8, 2017 and shall vest through March 8, 2020 and 18,333 of which were granted on May 31, 2016 and shall vest through May 31, 2019.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>By: Kevin Sun For: Donald M. Abbey</signatureName>
        <signatureDate>2018-06-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
