<?xml version="1.0" encoding="us-ascii"?>
<!--XBRL document created by DFIN IXG 1.0.0.0 using Fujitsu Interstage XWand-->
<schema targetNamespace="http://www.vanguard.com/20240523" elementFormDefault="qualified" xmlns="http://www.w3.org/2001/XMLSchema" xmlns:fixedincome="http://www.vanguard.com/20240523" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:dtr-types="http://www.xbrl.org/dtr/type/2022-03-31">
  <annotation>
    <appinfo>
      <link:linkbaseRef xlink:type="simple" xlink:href="fixedincome-20240523_pre.xml" xlink:title="Presentation Links, all" xlink:role="http://www.xbrl.org/2003/role/presentationLinkbaseRef" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" />
      <link:linkbaseRef xlink:type="simple" xlink:href="fixedincome-20240523_cal.xml" xlink:title="Calculation Links, all" xlink:role="http://www.xbrl.org/2003/role/calculationLinkbaseRef" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" />
      <link:linkbaseRef xlink:type="simple" xlink:href="fixedincome-20240523_def.xml" xlink:title="Definition Links, all" xlink:role="http://www.xbrl.org/2003/role/definitionLinkbaseRef" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" />
      <link:linkbaseRef xlink:type="simple" xlink:href="fixedincome-20240523_lab.xml" xlink:title="Label Links, all" xlink:role="http://www.xbrl.org/2003/role/labelLinkbaseRef" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" />
      <link:roleType roleURI="http://www.vanguard.com/role/DocumentDocumentandEntityInformationElements" id="httpwwwvanguardcomroleDocumentDocumentandEntityInformationElements">
        <link:definition>000000 - Document - Document and Entity Information {Elements}</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.vanguard.com/role/ScheduleAnnualFundOperatingExpenses000013" id="httpwwwvanguardcomroleScheduleAnnualFundOperatingExpenses000013">
        <link:definition>000013 - Schedule - Annual Fund Operating Expenses</link:definition>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.vanguard.com/role/DisclosureRiskReturnDetailDataElementsVanguardUltra-Short-TermBondFundRetail" id="httpwwwvanguardcomroleDisclosureRiskReturnDetailDataElementsVanguardUltraShortTermBondFundRetail">
        <link:definition>000019 - Disclosure - Risk/Return Detail Data {Elements} - Vanguard Ultra-Short-Term Bond Fund (Retail)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.vanguard.com/role/DisclosureRiskReturnDetailDataElementsVanguardShort-TermTreasuryFundRetail" id="httpwwwvanguardcomroleDisclosureRiskReturnDetailDataElementsVanguardShortTermTreasuryFundRetail">
        <link:definition>000029 - Disclosure - Risk/Return Detail Data {Elements} - Vanguard Short-Term Treasury Fund (Retail)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.vanguard.com/role/DisclosureRiskReturnDetailDataElementsVanguardShort-TermFederalFundRetail" id="httpwwwvanguardcomroleDisclosureRiskReturnDetailDataElementsVanguardShortTermFederalFundRetail">
        <link:definition>000039 - Disclosure - Risk/Return Detail Data {Elements} - Vanguard Short-Term Federal Fund (Retail)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.vanguard.com/role/DisclosureRiskReturnDetailDataElementsVanguardShort-TermInvestment-GradeFundRetail" id="httpwwwvanguardcomroleDisclosureRiskReturnDetailDataElementsVanguardShortTermInvestmentGradeFundRetail">
        <link:definition>000049 - Disclosure - Risk/Return Detail Data {Elements} - Vanguard Short-Term Investment-Grade Fund (Retail)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.vanguard.com/role/DisclosureRiskReturnDetailDataElementsVanguardIntermediate-TermTreasuryFundRetail" id="httpwwwvanguardcomroleDisclosureRiskReturnDetailDataElementsVanguardIntermediateTermTreasuryFundRetail">
        <link:definition>000059 - Disclosure - Risk/Return Detail Data {Elements} - Vanguard Intermediate-Term Treasury Fund (Retail)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.vanguard.com/role/DisclosureRiskReturnDetailDataElementsVanguardIntermediate-TermInvestment-GradeFundRetail" id="httpwwwvanguardcomroleDisclosureRiskReturnDetailDataElementsVanguardIntermediateTermInvestmentGradeFundRetail">
        <link:definition>000069 - Disclosure - Risk/Return Detail Data {Elements} - Vanguard Intermediate-Term Investment-Grade Fund (Retail)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.vanguard.com/role/DisclosureRiskReturnDetailDataElementsVanguardGNMAFundRetail" id="httpwwwvanguardcomroleDisclosureRiskReturnDetailDataElementsVanguardGNMAFundRetail">
        <link:definition>000079 - Disclosure - Risk/Return Detail Data {Elements} - Vanguard GNMA Fund (Retail)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.vanguard.com/role/DisclosureRiskReturnDetailDataElementsVanguardLong-TermTreasuryFundRetail" id="httpwwwvanguardcomroleDisclosureRiskReturnDetailDataElementsVanguardLongTermTreasuryFundRetail">
        <link:definition>000089 - Disclosure - Risk/Return Detail Data {Elements} - Vanguard Long-Term Treasury Fund (Retail)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.vanguard.com/role/DisclosureRiskReturnDetailDataElementsVanguardLong-TermInvestment-GradeFundRetail" id="httpwwwvanguardcomroleDisclosureRiskReturnDetailDataElementsVanguardLongTermInvestmentGradeFundRetail">
        <link:definition>000099 - Disclosure - Risk/Return Detail Data {Elements} - Vanguard Long-Term Investment-Grade Fund (Retail)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.vanguard.com/role/DisclosureRiskReturnDetailDataElementsVanguardShort-TermInvestment-GradeFundInstitutional" id="httpwwwvanguardcomroleDisclosureRiskReturnDetailDataElementsVanguardShortTermInvestmentGradeFundInstitutional">
        <link:definition>000109 - Disclosure - Risk/Return Detail Data {Elements} - Vanguard Short-Term Investment-Grade Fund (Institutional)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.vanguard.com/role/DisclosureRiskReturnDetailDataElementsVanguardHigh-YieldCorporateFundRetail" id="httpwwwvanguardcomroleDisclosureRiskReturnDetailDataElementsVanguardHighYieldCorporateFundRetail">
        <link:definition>000119 - Disclosure - Risk/Return Detail Data {Elements} - Vanguard High-Yield Corporate Fund (Retail)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://www.vanguard.com/role/DisclosureRiskReturnDetailDataElementsVanguardRealEstateIIIndexFundInstitutionalPlus" id="httpwwwvanguardcomroleDisclosureRiskReturnDetailDataElementsVanguardRealEstateIIIndexFundInstitutionalPlus">
        <link:definition>000129 - Disclosure - Risk/Return Detail Data {Elements} - Vanguard Real Estate II Index Fund (Institutional Plus)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
    </appinfo>
  </annotation>
  <import namespace="http://www.xbrl.org/2003/instance" schemaLocation="http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd" />
  <import namespace="http://www.xbrl.org/2003/linkbase" schemaLocation="http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" />
  <import namespace="http://xbrl.sec.gov/rr/2023" schemaLocation="https://xbrl.sec.gov/rr/2023/rr-2023.xsd" />
  <import namespace="http://xbrl.sec.gov/dei/2023" schemaLocation="https://xbrl.sec.gov/dei/2023/dei-2023.xsd" />
  <import namespace="http://www.xbrl.org/dtr/type/2022-03-31" schemaLocation="https://www.xbrl.org/dtr/type/2022-03-31/types.xsd" />
  <element name="RetailMember" id="fixedincome_RetailMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="S000048081Member" id="fixedincome_S000048081Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="ReturnAfterTaxesonDistributionsMember" id="fixedincome_ReturnAfterTaxesonDistributionsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="ReturnAfterTaxesonDistributionsandSaleofFundSharesMember" id="fixedincome_ReturnAfterTaxesonDistributionsandSaleofFundSharesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="BloombergUSTreasuryBellwethers1YearIndexMember" id="fixedincome_BloombergUSTreasuryBellwethers1YearIndexMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="BloombergUSAggregateBondIndexMember" id="fixedincome_BloombergUSAggregateBondIndexMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="C000151976Member" id="fixedincome_C000151976Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="C000151975Member" id="fixedincome_C000151975Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="S000002583Member" id="fixedincome_S000002583Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="BloombergUS15YearTreasuryBondIndexMember" id="fixedincome_BloombergUS15YearTreasuryBondIndexMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="C000007089Member" id="fixedincome_C000007089Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="C000007090Member" id="fixedincome_C000007090Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="S000002590Member" id="fixedincome_S000002590Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="BloombergUS15YearGovernmentBondIndexMember" id="fixedincome_BloombergUS15YearGovernmentBondIndexMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="C000007105Member" id="fixedincome_C000007105Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="C000007106Member" id="fixedincome_C000007106Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="S000002591Member" id="fixedincome_S000002591Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="BloombergUS15YearCreditBondIndexMember" id="fixedincome_BloombergUS15YearCreditBondIndexMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="C000007107Member" id="fixedincome_C000007107Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="C000007108Member" id="fixedincome_C000007108Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="S000002587Member" id="fixedincome_S000002587Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="BloombergUS510YearTreasuryBondIndexMember" id="fixedincome_BloombergUS510YearTreasuryBondIndexMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="C000007099Member" id="fixedincome_C000007099Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="C000007100Member" id="fixedincome_C000007100Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="S000002586Member" id="fixedincome_S000002586Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="BloombergUS510YearCreditBondIndexMember" id="fixedincome_BloombergUS510YearCreditBondIndexMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="C000007097Member" id="fixedincome_C000007097Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="C000007098Member" id="fixedincome_C000007098Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="S000002582Member" id="fixedincome_S000002582Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="BloombergUSGNMABondIndexMember" id="fixedincome_BloombergUSGNMABondIndexMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="C000007087Member" id="fixedincome_C000007087Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="C000007088Member" id="fixedincome_C000007088Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="S000002589Member" id="fixedincome_S000002589Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="BloombergUSLongTreasuryBondIndexMember" id="fixedincome_BloombergUSLongTreasuryBondIndexMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="C000007103Member" id="fixedincome_C000007103Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="C000007104Member" id="fixedincome_C000007104Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="S000002588Member" id="fixedincome_S000002588Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="BloombergUSLongCreditAorBetterBondIndexMember" id="fixedincome_BloombergUSLongCreditAorBetterBondIndexMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="C000007101Member" id="fixedincome_C000007101Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="C000007102Member" id="fixedincome_C000007102Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="InstitutionalMember" id="fixedincome_InstitutionalMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="C000007109Member" id="fixedincome_C000007109Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="S000002584Member" id="fixedincome_S000002584Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="HighYieldCorporateCompositeIndexMember" id="fixedincome_HighYieldCorporateCompositeIndexMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="BloombergUSCorporateHighYieldBondIndexMember" id="fixedincome_BloombergUSCorporateHighYieldBondIndexMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="C000007092Member" id="fixedincome_C000007092Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="C000007093Member" id="fixedincome_C000007093Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="InstitutionalPlusMember" id="fixedincome_InstitutionalPlusMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="S000059086Member" id="fixedincome_S000059086Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="RealEstateSplicedIndexMember" id="fixedincome_RealEstateSplicedIndexMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="MSCIUSInvestableMarketRealEstate2550IndexMember" id="fixedincome_MSCIUSInvestableMarketRealEstate2550IndexMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="DowJonesUSTotalStockMarketFloatAdjustedIndexMember" id="fixedincome_DowJonesUSTotalStockMarketFloatAdjustedIndexMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="C000193720Member" id="fixedincome_C000193720Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <element name="NondiversificationRiskMember" id="fixedincome_NondiversificationRiskMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
</schema>
