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  <xsd:element id="lh_PaymentsOnZeroCouponNotes" name="PaymentsOnZeroCouponNotes" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element id="lh_Paymentsonbridgeloan" name="Paymentsonbridgeloan" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="lh_PerShareAmountAbstract" name="PerShareAmountAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="lh_Percentoflowestmaximumcaponpayments" name="Percentoflowestmaximumcaponpayments" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="lh_Postcombinationaccelerationofstockcompensationexpense" name="Postcombinationaccelerationofstockcompensationexpense" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="lh_PreviouslyRecordedLitigationReserveInConnectionWithFalseClaimsActLawsuit" name="PreviouslyRecordedLitigationReserveInConnectionWithFalseClaimsActLawsuit" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="lh_PrincipalAmountOfZeroCouponSubordinatedNotes" name="PrincipalAmountOfZeroCouponSubordinatedNotes" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element id="lh_Proceedsfrombridgeloan" name="Proceedsfrombridgeloan" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="lh_Proceedsfromissuanceofstocktoemployees" name="Proceedsfromissuanceofstocktoemployees" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="lh_ProposedDamagesPerViolation" name="ProposedDamagesPerViolation" nillable="true" substitutionGroup="xbrli:item" type="us-types:perUnitItemType" xbrli:periodType="instant" />
  <xsd:element id="lh_ReductionforPlaintiffNegligence" name="ReductionforPlaintiffNegligence" nillable="true" substitutionGroup="xbrli:item" type="num:percentItemType" xbrli:periodType="duration" />
  <xsd:element id="lh_RestrictedStockAwardsAndPerformanceSharesSurrendered" name="RestrictedStockAwardsAndPerformanceSharesSurrendered" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="lh_RestructuringReserveSettledWithCashAndOtherAdjustment" name="RestructuringReserveSettledWithCashAndOtherAdjustment" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element id="lh_RevolvingCreditFacilitycovenanttermsceiling" name="RevolvingCreditFacilitycovenanttermsceiling" nillable="true" substitutionGroup="xbrli:item" type="xbrli:pureItemType" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="lh_ScheduleOfOtherIntangibleAssetsByMajorClassAxis" name="ScheduleOfOtherIntangibleAssetsByMajorClassAxis" nillable="true" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="lh_ScheduleOfOtherIntangibleAssetsByMajorClassDomain" name="ScheduleOfOtherIntangibleAssetsByMajorClassDomain" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="lh_SegmentReconciliationofOperatingIncometoConsolidatedAbstract" name="SegmentReconciliationofOperatingIncometoConsolidatedAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="lh_SeniorNotesDue2015Member" name="SeniorNotesDue2015Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="lh_SeniorNotesDue2016Member" name="SeniorNotesDue2016Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="lh_SeniorNotesDue2017Member" name="SeniorNotesDue2017Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="lh_SeniorNotesDue2020Member" name="SeniorNotesDue2020Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="lh_SeniorNotesDue2022Member" name="SeniorNotesDue2022Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="lh_SeniorNotesFairValue" name="SeniorNotesFairValue" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="lh_Seniornotesdue2018Member" name="Seniornotesdue2018Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="lh_Seniornotesdue2023Member" name="Seniornotesdue2023Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="lh_Seniornotesdue2025Member" name="Seniornotesdue2025Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="lh_Seniornotesdue2025MemberMember" name="Seniornotesdue2025MemberMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="lh_Seniornotesdue2045Member" name="Seniornotesdue2045Member" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="lh_SharesAbstract" name="SharesAbstract" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="lh_Sharestobegrantedperacquireeshareoutstandinginproposedacquisition" name="Sharestobegrantedperacquireeshareoutstandinginproposedacquisition" nillable="true" substitutionGroup="xbrli:item" type="xbrli:sharesItemType" xbrli:periodType="instant" />
  <xsd:element id="lh_StockConversionRateForZeroCouponSubordinatedNotes" name="StockConversionRateForZeroCouponSubordinatedNotes" nillable="true" substitutionGroup="xbrli:item" type="xbrli:decimalItemType" xbrli:periodType="instant" />
  <xsd:element abstract="true" id="lh_TargetRatiotoResumeShareRepurchaseMember" name="TargetRatiotoResumeShareRepurchaseMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="lh_TermLoanMember" name="TermLoanMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="lh_Totalacquisitionconsiderationcashandnoncash" name="Totalacquisitionconsiderationcashandnoncash" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element id="lh_Transactioncosts" name="Transactioncosts" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="lh_TriStateClinicalLaboratoryServicesLlcMember" name="TriStateClinicalLaboratoryServicesLlcMember" nillable="true" substitutionGroup="xbrli:item" type="nonnum:domainItemType" xbrli:periodType="duration" />
  <xsd:element id="lh_Writeoffofbridgeandotherdeferredfinancingcosts" name="Writeoffofbridgeandotherdeferredfinancingcosts" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="debit" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="lh_ZeroCouponConvertibleSubordinatedNotesLineItems" name="ZeroCouponConvertibleSubordinatedNotesLineItems" nillable="true" substitutionGroup="xbrli:item" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element abstract="true" id="lh_ZeroCouponConvertibleSubordinatedNotesTable" name="ZeroCouponConvertibleSubordinatedNotesTable" nillable="true" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType" xbrli:periodType="duration" />
  <xsd:element id="lh_ZeroCouponNotesFairValue" name="ZeroCouponNotesFairValue" nillable="true" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType" xbrli:balance="credit" xbrli:periodType="instant" />
</xsd:schema>
</XBRL>
