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      </link:roleType>
      <link:roleType id="SummaryOfSignificantAccountingPoliciesTables" roleURI="http://www.tandemdiabetes.com/role/SummaryOfSignificantAccountingPoliciesTables">
        <link:definition>2302301 - Disclosure - Summary of Significant Accounting Policies (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
    </xsd:appinfo>
  </xsd:annotation>
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  <xsd:element abstract="true" id="tndm_AccountsReceivableAndInventoriesDisclosureAbstract" name="AccountsReceivableAndInventoriesDisclosureAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="tndm_AccountsReceivableAndInventoryDisclosureTextBlock" name="AccountsReceivableAndInventoryDisclosureTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element id="tndm_AllowanceForSalesReturns" name="AllowanceForSalesReturns" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="tndm_CashCashEquivalentsAndShortTermInvestmentsLineItems" name="CashCashEquivalentsAndShortTermInvestmentsLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="tndm_CashCashEquivalentsAndShortTermInvestmentsTable" name="CashCashEquivalentsAndShortTermInvestmentsTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="tndm_CashEquivalentsMaturityTerm" name="CashEquivalentsMaturityTerm" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="tndm_CommonStockWarrantExpiringBetweenAugust2021andAugust2022Member" name="CommonStockWarrantExpiringBetweenAugust2021andAugust2022Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="tndm_CommonStockWarrantExpiringMarch2027Member" name="CommonStockWarrantExpiringMarch2027Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="tndm_CommonStockWarrants" name="CommonStockWarrants" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="tndm_ComplementaryProductsMember" name="ComplementaryProductsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="tndm_ContingentEmployeeStockOptionsMember" name="ContingentEmployeeStockOptionsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="tndm_DifferenceBetweenLeasesGuidanceInEffectBeforeAndAfterTopic842Member" name="DifferenceBetweenLeasesGuidanceInEffectBeforeAndAfterTopic842Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="tndm_FairValueOfCommonStockWarrantsAtTimeOfExercise" name="FairValueOfCommonStockWarrantsAtTimeOfExercise" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="tndm_FairValueOfWarrantLiability" name="FairValueOfWarrantLiability" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="tndm_HighBluffDriveSanDiegoCaliforniaMember" name="HighBluffDriveSanDiegoCaliforniaMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="tndm_InsulinPumpMember" name="InsulinPumpMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="tndm_LeaseArrangementsAxis" name="LeaseArrangementsAxis" nillable="true" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="tndm_LeaseArrangementsDomain" name="LeaseArrangementsDomain" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="tndm_NumberOfLegalProceedingsRegulatoryMattersOrOtherDisputesOrClaims" name="NumberOfLegalProceedingsRegulatoryMattersOrOtherDisputesOrClaims" nillable="true" substitutionGroup="xbrli:item" type="xbrli:integerItemType" xbrli:periodType="duration" />
  <xsd:element id="tndm_OfferedPeriodForSalesReturnPriorToExpiration" name="OfferedPeriodForSalesReturnPriorToExpiration" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="tndm_OfferingPeriod" name="OfferingPeriod" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="tndm_OrganizationAndBasisOfPresentationLineItems" name="OrganizationAndBasisOfPresentationLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="tndm_OrganizationAndBasisOfPresentationTable" name="OrganizationAndBasisOfPresentationTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="tndm_ProductLifeSpanTerm" name="ProductLifeSpanTerm" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="tndm_ProductsWarrantyPeriod" name="ProductsWarrantyPeriod" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="tndm_PublicOfferingPeriod" name="PublicOfferingPeriod" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element id="tndm_PurchasePeriod" name="PurchasePeriod" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="tndm_ScheduleOfCommonStockReservedForFutureIssuanceTableTextBlock" name="ScheduleOfCommonStockReservedForFutureIssuanceTableTextBlock" nillable="true" substitutionGroup="xbrli:item" type="nonnum:textBlockItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="tndm_SecondaryPublicOfferingMember" name="SecondaryPublicOfferingMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="tndm_SeriesAWarrantsMember" name="SeriesAWarrantsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="tndm_ShorelineDriveBoiseIdahoMember" name="ShorelineDriveBoiseIdahoMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="tndm_ShortTermInvestmentsMaturity" name="ShortTermInvestmentsMaturity" nillable="true" substitutionGroup="xbrli:item" type="xbrli:durationItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="tndm_SlimCartridgesAndInfusionSetsMember" name="SlimCartridgesAndInfusionSetsMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="tndm_StockIssuedDuringPeriodSharesCommonStockWarrantsExercised" name="StockIssuedDuringPeriodSharesCommonStockWarrantsExercised" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="duration" />
  <xsd:element id="tndm_StockIssuedDuringPeriodValueCommonStockWarrantsExercised" name="StockIssuedDuringPeriodValueCommonStockWarrantsExercised" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="tndm_StockOptionsIssuedAndOutstandingMember" name="StockOptionsIssuedAndOutstandingMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="tndm_SummaryOfSignificantAccountingPoliciesLineItems" name="SummaryOfSignificantAccountingPoliciesLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="tndm_SummaryOfSignificantAccountingPoliciesTable" name="SummaryOfSignificantAccountingPoliciesTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="tndm_TandemPumpMember" name="TandemPumpMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="tndm_TwoThousandThirteenPlanMember" name="TwoThousandThirteenPlanMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="tndm_VistaSorrentoLeaseMember" name="VistaSorrentoLeaseMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="tndm_VistaSorrentoParkwayLeaseMember" name="VistaSorrentoParkwayLeaseMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
</xsd:schema>
