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  <xs:element id="lh_SeniorNotesDue2030Member" abstract="true" name="SeniorNotesDue2030Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_SeniorNotesDue2032Member" abstract="true" name="SeniorNotesDue2032Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_SeniorNotesDue2034Member" abstract="true" name="SeniorNotesDue2034Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_SeniorNotesDue2025PaidIn2024Member" abstract="true" name="SeniorNotesDue2025PaidIn2024Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_SwapTypeAxis" abstract="true" name="SwapTypeAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="lh_SwapTypeDomain" abstract="true" name="SwapTypeDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="lh_A2022SwapAgreementsMember" abstract="true" name="A2022SwapAgreementsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="lh_A2018SwapAgreementsMember" abstract="true" name="A2018SwapAgreementsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="lh_AountGuaranteedUnder2024Indenture" abstract="false" name="AountGuaranteedUnder2024Indenture" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_FuturePaymentsOnRevolvingCreditFacility" abstract="false" name="FuturePaymentsOnRevolvingCreditFacility" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_CommonSharesIssuedRollforwardAbstract" abstract="true" name="CommonSharesIssuedRollforwardAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="lh_CommonsStockIssuedDuringPeriodSharesEmployeeStockPlans" abstract="false" name="CommonsStockIssuedDuringPeriodSharesEmployeeStockPlans" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="lh_CommonSharesHeldInTreasuryRollforwardAbstract" abstract="true" name="CommonSharesHeldInTreasuryRollforwardAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="lh_OutstandingStockRepurchaseAuthorizationAbstract" abstract="true" name="OutstandingStockRepurchaseAuthorizationAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="lh_CommonStockRepurchaseAuthorizationOutstanding" abstract="false" name="CommonStockRepurchaseAuthorizationOutstanding" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_AccumulatedOtherComprehensiveEarningsAbstract" abstract="true" name="AccumulatedOtherComprehensiveEarningsAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="lh_PensionSettlementMember" abstract="true" name="PensionSettlementMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_A2022ShareRepurchasesMember" abstract="true" name="A2022ShareRepurchasesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="lh_O2025Q1DividendsMember" abstract="true" name="O2025Q1DividendsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_PreferredStockOutstanding" abstract="false" name="PreferredStockOutstanding" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_FederalLossCarryoverDomain" abstract="true" name="FederalLossCarryoverDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="lh_Post2017Member" abstract="true" name="Post2017Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="lh_FederalTaxLossCarryovers" abstract="false" name="FederalTaxLossCarryovers" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_ForeignTaxLossCarryoversExpireBy2043" abstract="false" name="ForeignTaxLossCarryoversExpireBy2043" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_EffectiveIncomeTaxReconciliationDeferredTaxAdjustments" abstract="false" name="EffectiveIncomeTaxReconciliationDeferredTaxAdjustments" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="lh_IncrementalIncomeTaxExpenseAttributableToPillarTwo" abstract="false" name="IncrementalIncomeTaxExpenseAttributableToPillarTwo" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_IncomeLossFromContinuingOperationsBeforeIncomeTaxesAndMinorityInterestAbstract" abstract="true" name="IncomeLossFromContinuingOperationsBeforeIncomeTaxesAndMinorityInterestAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="lh_FederalandStateAttributeCarryforwards" abstract="false" name="FederalandStateAttributeCarryforwards" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_DeferredTaxAssetRightOfUseAsset" abstract="false" name="DeferredTaxAssetRightOfUseAsset" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_ForeignTaxLossCarryovers" abstract="false" name="ForeignTaxLossCarryovers" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_ForeignTaxLossCarryoverValuationAllowance" abstract="false" name="ForeignTaxLossCarryoverValuationAllowance" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_ForeignTaxLossCarryoversExpirein2034" abstract="false" name="ForeignTaxLossCarryoversExpirein2034" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_ReversalofAccruedIncomeTaxPenaltiesAndInterest" abstract="false" name="ReversalofAccruedIncomeTaxPenaltiesAndInterest" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_UnrecognizedTaxBenefitsIncreaseinReserveFromAcquisition" abstract="false" name="UnrecognizedTaxBenefitsIncreaseinReserveFromAcquisition" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_UnrecognizedTaxBenefitsIncreasesDecreasesResultingFromPriorPeriodTaxPositions" abstract="false" name="UnrecognizedTaxBenefitsIncreasesDecreasesResultingFromPriorPeriodTaxPositions" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_RestrictedStockAndPerformanceSharesMember" abstract="true" name="RestrictedStockAndPerformanceSharesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="lh_EmployeeStockPurchasePlanMember" abstract="true" name="EmployeeStockPurchasePlanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="lh_EmployeeStockPurchasePlanNumberOfSharesPurchased" abstract="false" name="EmployeeStockPurchasePlanNumberOfSharesPurchased" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="lh_EmployeeStockPurchasePlanFairValueEmployeePurchaseRight" abstract="false" name="EmployeeStockPurchasePlanFairValueEmployeePurchaseRight" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:perShareItemType"/>
  <xs:element id="lh_EmployeeStockPurchasePlanNumberOfAuthorizedShares" abstract="false" name="EmployeeStockPurchasePlanNumberOfAuthorizedShares" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="lh_EmployeeStockPurchasePlanPercentOfMarketPrice" abstract="false" name="EmployeeStockPurchasePlanPercentOfMarketPrice" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="lh_EmployeeStockPurchasePlanExpense" abstract="false" name="EmployeeStockPurchasePlanExpense" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_ShareBasedCompensationArrangementPerformanceShareAwardsVestingConditions" abstract="false" name="ShareBasedCompensationArrangementPerformanceShareAwardsVestingConditions" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="lh_RestrictedStockPerformanceSharesExpense" abstract="false" name="RestrictedStockPerformanceSharesExpense" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_LossContingencyDamagesTypeAxis" abstract="true" name="LossContingencyDamagesTypeAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="lh_LossContingencyDamagesTypeDomain" abstract="true" name="LossContingencyDamagesTypeDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_InitialDamagesMember" abstract="true" name="InitialDamagesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_EnhancedDamagesMember" abstract="true" name="EnhancedDamagesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_SupplementalDamagesMember" abstract="true" name="SupplementalDamagesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_RoyaltyDamagesMember" abstract="true" name="RoyaltyDamagesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_InternationalDevelopedMember" abstract="true" name="InternationalDevelopedMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="lh_UsFixedIncomeMember" abstract="true" name="UsFixedIncomeMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="lh_MutualFundsMember" abstract="true" name="MutualFundsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="lh_UKPlanMember" abstract="true" name="UKPlanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="lh_Maximumdeferralpercentageofannualbasesalary" abstract="false" name="Maximumdeferralpercentageofannualbasesalary" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="lh_DefinedBenefitPlanAssumptionsUsedExpectedLongTermReturnOnAssets" abstract="false" name="DefinedBenefitPlanAssumptionsUsedExpectedLongTermReturnOnAssets" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="lh_DefinedBenefitPlanExpectedRateOfReturnOnAssetsOtherAssets" abstract="false" name="DefinedBenefitPlanExpectedRateOfReturnOnAssetsOtherAssets" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="lh_DefinedBenefitPlanAmortizationAndDeferral" abstract="false" name="DefinedBenefitPlanAmortizationAndDeferral" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_DefinedBenefitPlanActualAssetAllocation" abstract="false" name="DefinedBenefitPlanActualAssetAllocation" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="lh_DefinedContributionPlanTotalExpense" abstract="false" name="DefinedContributionPlanTotalExpense" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_Maximumdeferralpercentageofannualcashincentivepay" abstract="false" name="Maximumdeferralpercentageofannualcashincentivepay" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="lh_CashBalanceRetirementPlanMember" abstract="true" name="CashBalanceRetirementPlanMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="lh_A2034SwapAgreementsMember" abstract="true" name="A2034SwapAgreementsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_IncreaseDecreaseInNoncontrollingInterestPut" abstract="false" name="IncreaseDecreaseInNoncontrollingInterestPut" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_FairValueLiabilitiesMeasuredOnRecurringBasisNoncontrollingInterestPuts" abstract="false" name="FairValueLiabilitiesMeasuredOnRecurringBasisNoncontrollingInterestPuts" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_FairValueLiabilitiesMeasuredOnRecurringBasisDeferredCompensationLiability" abstract="false" name="FairValueLiabilitiesMeasuredOnRecurringBasisDeferredCompensationLiability" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_Contingentconsiderationadjustment" abstract="false" name="Contingentconsiderationadjustment" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_SeniorNotesFairValue" abstract="false" name="SeniorNotesFairValue" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_SeniorNotesDue2031Member" abstract="true" name="SeniorNotesDue2031Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="lh_A2029SwapAgreementsMember" abstract="true" name="A2029SwapAgreementsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_A2031And2034SwapAgreementsMember" abstract="true" name="A2031And2034SwapAgreementsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_A2029And2034SwapAgreements" abstract="false" name="A2029And2034SwapAgreements" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_NumberOfForeignCurrencyDerivativesHeldQ3" abstract="false" name="NumberOfForeignCurrencyDerivativesHeldQ3" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="lh_UsGaap_NumberOfForeignCurrencyDerivativesHeldQ2" abstract="false" name="UsGaap_NumberOfForeignCurrencyDerivativesHeldQ2" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="lh_DerivativeInterestRateSwap" abstract="false" name="DerivativeInterestRateSwap" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_ThreeMonthLIBOR" abstract="false" name="ThreeMonthLIBOR" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="lh_CashPaidDuringPeriodForAbstract" abstract="true" name="CashPaidDuringPeriodForAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="lh_InterestPaidInCash" abstract="false" name="InterestPaidInCash" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_DecreaseInCapitalExpendituresIncurredButNotPaid" abstract="false" name="DecreaseInCapitalExpendituresIncurredButNotPaid" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_IncreaseInCapitalExpendituresIncurredButNotPaid" abstract="false" name="IncreaseInCapitalExpendituresIncurredButNotPaid" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_Freight" abstract="false" name="Freight" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_NetRestructuringCharges" abstract="false" name="NetRestructuringCharges" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="lh_MarkS.SchroederMember" abstract="true" name="MarkS.SchroederMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_AmyB.SummyMember" abstract="true" name="AmyB.SummyMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_MarkS.SchroederTradingArrangementStockOptionsMember" abstract="true" name="MarkS.SchroederTradingArrangementStockOptionsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="lh_MarkS.SchroederTradingArrangementPreviouslyAcquiredCommonStockMember" abstract="true" name="MarkS.SchroederTradingArrangementPreviouslyAcquiredCommonStockMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
</xs:schema>
