<?xml version="1.0" encoding="us-ascii"?>
<!-- DFIN ActiveDisclosure(SM) XBRL Schema Document - http://www.dfinsolutions.com/ -->
<!-- Creation Date      : 2022-02-24T16:16:42.2400299+00:00 -->
<!-- Version            : 5.0.1.728 -->
<!-- Package ID         : 02ec438ba1b146aa805b0d67feaf3ff0 -->
<!-- Copyright (c) 2022 Donnelley Financial Solutions, Inc. All Rights Reserved. -->
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  <xsd:element id="icfi_ChangeInContractWithCustomerAssetsLiabilitiesNetCurrent" name="ChangeInContractWithCustomerAssetsLiabilitiesNetCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="icfi_ContractWithCustomerAssetsLiabilitiesNetCurrent" name="ContractWithCustomerAssetsLiabilitiesNetCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="icfi_ChangeInContractWithCustomerAssetNetCurrent" name="ChangeInContractWithCustomerAssetNetCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="icfi_ChangeInContractWithCustomerLiabilityCurrent" name="ChangeInContractWithCustomerLiabilityCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="icfi_RevenueFromContractWithCustomerLineItems" name="RevenueFromContractWithCustomerLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="icfi_RevenueFromContractWithCustomerTable" name="RevenueFromContractWithCustomerTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="icfi_InterestRateSwapTwoPointEightFiveOneZeroPercentMember" name="InterestRateSwapTwoPointEightFiveOneZeroPercentMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="icfi_DeferredTaxAssetsForeignDeferredIncome" name="DeferredTaxAssetsForeignDeferredIncome" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="icfi_DeferredTaxAssetsAccruedBonus" name="DeferredTaxAssetsAccruedBonus" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="icfi_DeferredTaxAssetsAccruedLiabilitiesAndOtherNoncurrent" name="DeferredTaxAssetsAccruedLiabilitiesAndOtherNoncurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="icfi_DeferredTaxLiabilitiesRetentionCurrent" name="DeferredTaxLiabilitiesRetentionCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="icfi_DeferredTaxLiabilitiesPayrollTaxes" name="DeferredTaxLiabilitiesPayrollTaxes" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="icfi_DeferredTaxLiabilitiesUnbilledRevenue" name="DeferredTaxLiabilitiesUnbilledRevenue" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="icfi_DeferredTaxLiabilitiesOtherCurrent" name="DeferredTaxLiabilitiesOtherCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="icfi_IncomeTaxesLineItems" name="IncomeTaxesLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="icfi_IncomeTaxesTable" name="IncomeTaxesTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="icfi_TaxCutsAndJobsActOf2017CompleteAccountingChangeInTaxRateDeferredTaxAssetsAndLiabilitiesExpectedToReverseInFuture" name="TaxCutsAndJobsActOf2017CompleteAccountingChangeInTaxRateDeferredTaxAssetsAndLiabilitiesExpectedToReverseInFuture" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="icfi_StateAndForeignJurisdictionsMember" name="StateAndForeignJurisdictionsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="icfi_GovernmentAssistanceAxis" name="GovernmentAssistanceAxis" type="xbrli:stringItemType" substitutionGroup="xbrldt:dimensionItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="icfi_GovernmentAssistanceMember" name="GovernmentAssistanceMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="icfi_CoronavirusAidReliefAndEconomicSecurityActMember" name="CoronavirusAidReliefAndEconomicSecurityActMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="icfi_COVID19PandemicMember" name="COVID19PandemicMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="icfi_TaxCutsAndJobsActOf2017CompleteAccountingChangeInValuationAllowancesForCumulativeForiegnTaxCreditCarryForward" name="TaxCutsAndJobsActOf2017CompleteAccountingChangeInValuationAllowancesForCumulativeForiegnTaxCreditCarryForward" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="icfi_TaxCutsAndJobsActOf2017CompleteAccountingChangeInCumulativeForeignTaxCreditCarryForward" name="TaxCutsAndJobsActOf2017CompleteAccountingChangeInCumulativeForeignTaxCreditCarryForward" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="icfi_IncomeTaxesProvidedForAdditionalOutsideBasisDifferenceInherentInEntitiesAsResultOfReinvestment" name="IncomeTaxesProvidedForAdditionalOutsideBasisDifferenceInherentInEntitiesAsResultOfReinvestment" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="icfi_OperatingLossCarryforwardsExpirationYear" name="OperatingLossCarryforwardsExpirationYear" type="xbrli:gYearItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="icfi_OperatingLossCarryforwardsExpirationTerm" name="OperatingLossCarryforwardsExpirationTerm" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="icfi_TaxCreditCarryforwardExpirationYear" name="TaxCreditCarryforwardExpirationYear" type="xbrli:gYearItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="icfi_EffectiveIncomeTaxRateReconciliationExecutiveCompensation" name="EffectiveIncomeTaxRateReconciliationExecutiveCompensation" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="icfi_ExercisedOptionToDeferEmployerPortionOfSocialSecurityTaxDescription" name="ExercisedOptionToDeferEmployerPortionOfSocialSecurityTaxDescription" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="icfi_PercentageOfDeferredEmployerPortionOfSocialSecurityTaxRepayable" name="PercentageOfDeferredEmployerPortionOfSocialSecurityTaxRepayable" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="icfi_EmployerPortionOfSocialSecurityTaxRepayableDate" name="EmployerPortionOfSocialSecurityTaxRepayableDate" type="xbrli:dateItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="icfi_EmployerPortionOfSocialSecurityTaxRepayableRemainderDate" name="EmployerPortionOfSocialSecurityTaxRepayableRemainderDate" type="xbrli:dateItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="icfi_EmployerPortionOfSocialSecurityTaxDeferred" name="EmployerPortionOfSocialSecurityTaxDeferred" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="icfi_AccumulatedOtherComprehensiveIncomeLossCumulativeChangesInFairValueOnDerivativeDesignatedFromCashFlowHedgesEffectNetOfTaxMember" name="AccumulatedOtherComprehensiveIncomeLossCumulativeChangesInFairValueOnDerivativeDesignatedFromCashFlowHedgesEffectNetOfTaxMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="icfi_OmnibusPlanMember" name="OmnibusPlanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="icfi_NonemployeeDirectOrAwardsMember" name="NonemployeeDirectOrAwardsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="icfi_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedForfeitureRate" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedForfeitureRate" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="icfi_PriceRange1Member" name="PriceRange1Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="icfi_PriceRange2Member" name="PriceRange2Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="icfi_PriceRange3Member" name="PriceRange3Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="icfi_PriceRange4Member" name="PriceRange4Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="icfi_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsExpectedToVestNumber" name="SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsExpectedToVestNumber" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="icfi_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsExpectedToVestWeightedAverageGrantDateFairValue" name="SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsExpectedToVestWeightedAverageGrantDateFairValue" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="icfi_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExpectedToVestAggregateIntrinsicValue" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExpectedToVestAggregateIntrinsicValue" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="icfi_NumberOfPerformancePeriodInPerformanceBasedShareProgram" name="NumberOfPerformancePeriodInPerformanceBasedShareProgram" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="icfi_PercentageOfMultiplicationAwardByProduct" name="PercentageOfMultiplicationAwardByProduct" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="icfi_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExpectedToVest" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsExpectedToVest" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="icfi_EcoTechMember" name="EcoTechMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="icfi_TechnologyAndOtherIntangiblesMember" name="TechnologyAndOtherIntangiblesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="icfi_CreativeSystemsMember" name="CreativeSystemsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="icfi_IndemnityMember" name="IndemnityMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="icfi_BusinessCombinationAmortizationOfGoodwillAndOtherIntangiblesAmortizedForIncomeTaxPurposePeriod" name="BusinessCombinationAmortizationOfGoodwillAndOtherIntangiblesAmortizedForIncomeTaxPurposePeriod" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="icfi_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedWorkingCapital" name="BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedWorkingCapital" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="icfi_BusinessAcquisitionDiscountPercentageOnWarranty" name="BusinessAcquisitionDiscountPercentageOnWarranty" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="icfi_BusinessAcquisitionDiscountPercentageOnIndemnityLiabilities" name="BusinessAcquisitionDiscountPercentageOnIndemnityLiabilities" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="icfi_LineOfCreditFacilityConditionForShareRepurchasesLeverageRatio" name="LineOfCreditFacilityConditionForShareRepurchasesLeverageRatio" type="xbrli:pureItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="icfi_ShareRepurchaseApprovedStartingOnJanuaryElevenTwentyTwentyOneAndEndingNoLaterThanJuneThirtyTwentyTwentyOneMember" name="ShareRepurchaseApprovedStartingOnJanuaryElevenTwentyTwentyOneAndEndingNoLaterThanJuneThirtyTwentyTwentyOneMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="icfi_ShareRepurchaseApprovedStartingOnDecemberTwentyTwentyTwentyOneAndEndingNoLaterThanJuneThirtyTwentyTwentyTwoMember" name="ShareRepurchaseApprovedStartingOnDecemberTwentyTwentyTwentyOneAndEndingNoLaterThanJuneThirtyTwentyTwentyTwoMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="icfi_DeferredCompensationInvestmentsInCashSurrenderLifeInsuranceMember" name="DeferredCompensationInvestmentsInCashSurrenderLifeInsuranceMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="icfi_DeferredCompensationPlanLiabilitiesMember" name="DeferredCompensationPlanLiabilitiesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="icfi_AccruedExpensesAndOtherCurrentLiabilitiesMember" name="AccruedExpensesAndOtherCurrentLiabilitiesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="icfi_ContractTermPeriod" name="ContractTermPeriod" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="icfi_ContractAwardValue" name="ContractAwardValue" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="icfi_RoadHomeContractMember" name="RoadHomeContractMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="icfi_OCDVsICFEmergencyMember" name="OCDVsICFEmergencyMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="icfi_CommunityDevelopmentRelatedToClaim" name="CommunityDevelopmentRelatedToClaim" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="icfi_ShareBasedCompensationArrangementByShareBasedPaymentAwardGrantedAcceleratedAndVestedNumber" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardGrantedAcceleratedAndVestedNumber" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="icfi_MaximumDeferOfCompensationSubjectToStatutoryLimitationsPercentage" name="MaximumDeferOfCompensationSubjectToStatutoryLimitationsPercentage" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="icfi_PercentageOfEmployerMatchingContributionsConditionOne" name="PercentageOfEmployerMatchingContributionsConditionOne" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="icfi_PercentageOfEmployeeEntitledToEmployerMatchingContributionConditionOne" name="PercentageOfEmployeeEntitledToEmployerMatchingContributionConditionOne" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="icfi_PercentageOfEmployerMatchingContributionsConditionTwo" name="PercentageOfEmployerMatchingContributionsConditionTwo" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="icfi_PercentageOfEmployeeEntitledToEmployerMatchingContributionConditionTwo" name="PercentageOfEmployeeEntitledToEmployerMatchingContributionConditionTwo" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="icfi_DeferredCompensationOnPerformanceBonusesThatEligibleEmployeePercentage" name="DeferredCompensationOnPerformanceBonusesThatEligibleEmployeePercentage" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="icfi_EmployeeStockPurchasePlanSharesAuthorized" name="EmployeeStockPurchasePlanSharesAuthorized" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="icfi_EmployeeStockPurchasePlanAnnualMaximumPayrollDeduction" name="EmployeeStockPurchasePlanAnnualMaximumPayrollDeduction" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="icfi_StockIssuedDuringPeriodValueEmployeeStockPurchasePlansPerShare" name="StockIssuedDuringPeriodValueEmployeeStockPurchasePlansPerShare" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="icfi_EmployeeStockPurchasePlanNumberOfSharesAvailableForGrant" name="EmployeeStockPurchasePlanNumberOfSharesAvailableForGrant" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="icfi_AllowanceForDoubtfulAccountsForeignCurrencyTranslation" name="AllowanceForDoubtfulAccountsForeignCurrencyTranslation" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
</xsd:schema>
