﻿<?xml version="1.0" encoding="utf-8"?>
<Return returnVersion="2024v5.0" xmlns="http://www.irs.gov/efile">
  <ReturnHeader binaryAttachmentCnt="0">
    <ReturnTs>2025-11-12T20:05:19Z</ReturnTs>
    <TaxPeriodEndDt>2024-12-31</TaxPeriodEndDt>
    <ReturnTypeCd>990EZ</ReturnTypeCd>
    <TaxPeriodBeginDt>2024-01-01</TaxPeriodBeginDt>
    <Filer>
      <EIN>384107840</EIN>
      <BusinessName>
        <BusinessNameLine1Txt>INTERNATIONAL XENOTRANSPLANTATION ASSOCIATION</BusinessNameLine1Txt>
      </BusinessName>
      <BusinessNameControlTxt>INTE</BusinessNameControlTxt>
      <ForeignPhoneNum>5148741717201</ForeignPhoneNum>
      <ForeignAddress>
        <AddressLine1Txt>1245 - 740 Notre-Dame West</AddressLine1Txt>
        <CityNm>Montreal</CityNm>
        <ProvinceOrStateNm>QC</ProvinceOrStateNm>
        <CountryCd>CA</CountryCd>
        <ForeignPostalCd>H3C 3X6</ForeignPostalCd>
      </ForeignAddress>
    </Filer>
    <BusinessOfficerGrp>
      <PersonNm>Muhammad Mohiuddin</PersonNm>
      <PersonTitleTxt>President</PersonTitleTxt>
      <ForeignPhoneNum>5148741717201</ForeignPhoneNum>
      <SignatureDt>2025-11-12</SignatureDt>
    </BusinessOfficerGrp>
    <TaxYr>2024</TaxYr>
    <BuildTS>2025-03-06 01:10:19Z</BuildTS>
  </ReturnHeader>
  <ReturnData documentCnt="3">
    <IRS990EZ documentId="SIMPLE990" documentName="IRS990EZ" referenceDocumentName="IRS990ScheduleO ReasonableCauseExplanation TransfersPersonalBenefitsContractsDeclaration BinaryAttachment">
      <MethodOfAccountingAccrualInd>X</MethodOfAccountingAccrualInd>
      <ScheduleBNotRequiredInd>X</ScheduleBNotRequiredInd>
      <WebsiteAddressTxt>tts.org/ixa</WebsiteAddressTxt>
      <Organization501c3Ind referenceDocumentId="ScheduleA" referenceDocumentName="IRS990ScheduleA">X</Organization501c3Ind>
      <TypeOfOrganizationCorpInd>X</TypeOfOrganizationCorpInd>
      <GrossReceiptsAmt>63458</GrossReceiptsAmt>
      <InfoInScheduleOPartIInd>X</InfoInScheduleOPartIInd>
      <ContributionsGiftsGrantsEtcAmt>3613</ContributionsGiftsGrantsEtcAmt>
      <ProgramServiceRevenueAmt>20804</ProgramServiceRevenueAmt>
      <MembershipDuesAmt>13265</MembershipDuesAmt>
      <InvestmentIncomeAmt>14770</InvestmentIncomeAmt>
      <SaleOfAssetsGrossAmt>11006</SaleOfAssetsGrossAmt>
      <CostOrOtherBasisExpenseSaleAmt>6781</CostOrOtherBasisExpenseSaleAmt>
      <GainOrLossFromSaleOfAssetsAmt>4225</GainOrLossFromSaleOfAssetsAmt>
      <TotalRevenueAmt>56677</TotalRevenueAmt>
      <GrantsAndSimilarAmountsPaidAmt>7000</GrantsAndSimilarAmountsPaidAmt>
      <BenefitsPaidToOrForMembersAmt>11100</BenefitsPaidToOrForMembersAmt>
      <FeesAndOtherPymtToIndCntrctAmt>7378</FeesAndOtherPymtToIndCntrctAmt>
      <PrintingPublicationsPostageAmt>409</PrintingPublicationsPostageAmt>
      <OtherExpensesTotalAmt>8908</OtherExpensesTotalAmt>
      <TotalExpensesAmt>34795</TotalExpensesAmt>
      <ExcessOrDeficitForYearAmt>21882</ExcessOrDeficitForYearAmt>
      <NetAssetsOrFundBalancesBOYAmt>310379</NetAssetsOrFundBalancesBOYAmt>
      <OtherChangesInNetAssetsAmt>5278</OtherChangesInNetAssetsAmt>
      <NetAssetsOrFundBalancesEOYAmt>337539</NetAssetsOrFundBalancesEOYAmt>
      <InfoInScheduleOPartIIInd>X</InfoInScheduleOPartIIInd>
      <CashSavingsAndInvestmentsGrp>
        <BOYAmt>309112</BOYAmt>
        <EOYAmt>338804</EOYAmt>
      </CashSavingsAndInvestmentsGrp>
      <OtherAssetsTotalDetail>
        <BOYAmt>26256</BOYAmt>
        <EOYAmt>58513</EOYAmt>
      </OtherAssetsTotalDetail>
      <Form990TotalAssetsGrp>
        <BOYAmt>335368</BOYAmt>
        <EOYAmt>397317</EOYAmt>
      </Form990TotalAssetsGrp>
      <SumOfTotalLiabilitiesGrp>
        <BOYAmt>24989</BOYAmt>
        <EOYAmt>59778</EOYAmt>
      </SumOfTotalLiabilitiesGrp>
      <NetAssetsOrFundBalancesGrp>
        <BOYAmt>310379</BOYAmt>
        <EOYAmt>337539</EOYAmt>
      </NetAssetsOrFundBalancesGrp>
      <PrimaryExemptPurposeTxt>to promote xenotransplantation</PrimaryExemptPurposeTxt>
      <ProgramSrvcAccomplishmentGrp>
        <DescriptionProgramSrvcAccomTxt>All IXA members have access to Xenotransplantation, the association's official journal which provides its readership with rapid communication of new findings in the field of organ and tissue transplantation across species barriers.</DescriptionProgramSrvcAccomTxt>
        <ProgramServiceExpensesAmt>11100</ProgramServiceExpensesAmt>
      </ProgramSrvcAccomplishmentGrp>
      <ProgramSrvcAccomplishmentGrp>
        <DescriptionProgramSrvcAccomTxt>IXA awards several grants to individuals who made significant contributions to the field of xenotransplantation in order for these awardees to travel to present their research at IXA's biennial congress or to support and foster research in the field. Number of awardees = 1</DescriptionProgramSrvcAccomTxt>
        <GrantsAndAllocationsAmt>7000</GrantsAndAllocationsAmt>
        <ProgramServiceExpensesAmt>7000</ProgramServiceExpensesAmt>
      </ProgramSrvcAccomplishmentGrp>
      <TotalProgramServiceExpensesAmt>18100</TotalProgramServiceExpensesAmt>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm referenceDocumentName="CompensationExplanation">Wayne Hawthorne</PersonNm>
        <TitleTxt>Immediate Past President (2023-2025)</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>3.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
        <EmployeeBenefitProgramAmt>0</EmployeeBenefitProgramAmt>
        <ExpenseAccountOtherAllwncAmt>0</ExpenseAccountOtherAllwncAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm referenceDocumentName="CompensationExplanation">Muhammad Mohiuddin</PersonNm>
        <TitleTxt>President (2023-2025)</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>3.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
        <EmployeeBenefitProgramAmt>0</EmployeeBenefitProgramAmt>
        <ExpenseAccountOtherAllwncAmt>0</ExpenseAccountOtherAllwncAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm referenceDocumentName="CompensationExplanation">Jay Fishman</PersonNm>
        <TitleTxt>President-Elect (2023-2025)</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>3.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
        <EmployeeBenefitProgramAmt>0</EmployeeBenefitProgramAmt>
        <ExpenseAccountOtherAllwncAmt>0</ExpenseAccountOtherAllwncAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm referenceDocumentName="CompensationExplanation">Rita Bottino</PersonNm>
        <TitleTxt>Secretary-Treasurer (2021-2025)</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>3.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
        <EmployeeBenefitProgramAmt>0</EmployeeBenefitProgramAmt>
        <ExpenseAccountOtherAllwncAmt>0</ExpenseAccountOtherAllwncAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm referenceDocumentName="CompensationExplanation">Ik Jin Yun</PersonNm>
        <TitleTxt>Councilor (2021-2025)</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>1.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
        <EmployeeBenefitProgramAmt>0</EmployeeBenefitProgramAmt>
        <ExpenseAccountOtherAllwncAmt>0</ExpenseAccountOtherAllwncAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm referenceDocumentName="CompensationExplanation">Paolo Brenner</PersonNm>
        <TitleTxt>Councilor (2021-2025)</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>1.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
        <EmployeeBenefitProgramAmt>0</EmployeeBenefitProgramAmt>
        <ExpenseAccountOtherAllwncAmt>0</ExpenseAccountOtherAllwncAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm referenceDocumentName="CompensationExplanation">Hidetaka Hara</PersonNm>
        <TitleTxt>Councilor (2021-2025)</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>1.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
        <EmployeeBenefitProgramAmt>0</EmployeeBenefitProgramAmt>
        <ExpenseAccountOtherAllwncAmt>0</ExpenseAccountOtherAllwncAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm referenceDocumentName="CompensationExplanation">Gregory Korbutt</PersonNm>
        <TitleTxt>Councilor (2023-2027)</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>1.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
        <EmployeeBenefitProgramAmt>0</EmployeeBenefitProgramAmt>
        <ExpenseAccountOtherAllwncAmt>0</ExpenseAccountOtherAllwncAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm referenceDocumentName="CompensationExplanation">Raphael Meier</PersonNm>
        <TitleTxt>Councilor (2023-2027)</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>1.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
        <EmployeeBenefitProgramAmt>0</EmployeeBenefitProgramAmt>
        <ExpenseAccountOtherAllwncAmt>0</ExpenseAccountOtherAllwncAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm referenceDocumentName="CompensationExplanation">Robert Reiben</PersonNm>
        <TitleTxt>Councilor (2023-2027)</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>1.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
        <EmployeeBenefitProgramAmt>0</EmployeeBenefitProgramAmt>
        <ExpenseAccountOtherAllwncAmt>0</ExpenseAccountOtherAllwncAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <ActivitiesNotPreviouslyRptInd>false</ActivitiesNotPreviouslyRptInd>
      <ChgMadeToOrgnzngDocNotRptInd>false</ChgMadeToOrgnzngDocNotRptInd>
      <OrganizationHadUBIInd>false</OrganizationHadUBIInd>
      <SubjectToProxyTaxInd referenceDocumentName="IRS990ScheduleC">false</SubjectToProxyTaxInd>
      <OrganizationDissolvedEtcInd referenceDocumentName="IRS990ScheduleN BinaryAttachment">false</OrganizationDissolvedEtcInd>
      <Form1120PolFiledInd>false</Form1120PolFiledInd>
      <MadeLoansToFromOfficersInd>false</MadeLoansToFromOfficersInd>
      <EngagedInExcessBenefitTransInd referenceDocumentName="IRS990ScheduleL">false</EngagedInExcessBenefitTransInd>
      <ProhibitedTaxShelterTransInd>false</ProhibitedTaxShelterTransInd>
      <BooksInCareOfDetail>
        <PersonNm>Denise Rainville</PersonNm>
        <ForeignAddress>
          <AddressLine1Txt>1245 - 740 Notre-Dame West</AddressLine1Txt>
          <CityNm>Montreal</CityNm>
          <ProvinceOrStateNm>QC</ProvinceOrStateNm>
          <CountryCd>CA</CountryCd>
          <ForeignPostalCd>H3C 3X6</ForeignPostalCd>
        </ForeignAddress>
        <PhoneNum>4389924907</PhoneNum>
      </BooksInCareOfDetail>
      <ForeignFinancialAccountInd>false</ForeignFinancialAccountInd>
      <ForeignOfficeInd>false</ForeignOfficeInd>
      <DonorAdvisedFndsInd>false</DonorAdvisedFndsInd>
      <OperateHospitalInd>false</OperateHospitalInd>
      <TanningServicesProvidedInd>false</TanningServicesProvidedInd>
      <RelatedOrganizationCtrlEntInd>false</RelatedOrganizationCtrlEntInd>
      <TransactionWithControlEntInd>false</TransactionWithControlEntInd>
      <PoliticalCampaignActyInd referenceDocumentName="IRS990ScheduleC">false</PoliticalCampaignActyInd>
      <LobbyingActivitiesInd referenceDocumentName="IRS990ScheduleC">false</LobbyingActivitiesInd>
      <SchoolOperatingInd referenceDocumentName="IRS990ScheduleE">false</SchoolOperatingInd>
      <TrnsfrExmptNonChrtblRltdOrgInd>false</TrnsfrExmptNonChrtblRltdOrgInd>
      <PartVIOfCompOfHghstPdEmplTxt>NONE</PartVIOfCompOfHghstPdEmplTxt>
      <OtherEmployeePaidOver100kCnt>0</OtherEmployeePaidOver100kCnt>
      <PartVIHghstPdCntrctProfSrvcTxt>NONE</PartVIHghstPdCntrctProfSrvcTxt>
      <CntrctRcvdGreaterThan100KCnt>0</CntrctRcvdGreaterThan100KCnt>
      <FiledScheduleAInd>true</FiledScheduleAInd>
    </IRS990EZ>
    <IRS990ScheduleA documentId="ScheduleA" documentName="IRS990ScheduleA">
      <PublicOrganization170Ind>X</PublicOrganization170Ind>
      <SupportedOrganizationsCnt>0</SupportedOrganizationsCnt>
      <GiftsGrantsContriRcvd170Grp>
        <CurrentTaxYearMinus3YearsAmt>30270</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>14015</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>20265</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>16878</CurrentTaxYearAmt>
        <TotalAmt>81428</TotalAmt>
      </GiftsGrantsContriRcvd170Grp>
      <TotalCalendarYear170Grp>
        <CurrentTaxYearMinus4YearsAmt>0</CurrentTaxYearMinus4YearsAmt>
        <CurrentTaxYearMinus3YearsAmt>30270</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>14015</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>20265</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>16878</CurrentTaxYearAmt>
        <TotalAmt>81428</TotalAmt>
      </TotalCalendarYear170Grp>
      <PublicSupportTotal170Amt>81428</PublicSupportTotal170Amt>
      <GrossInvestmentIncome170Grp>
        <CurrentTaxYearMinus3YearsAmt>3682</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>2870</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>7233</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>18995</CurrentTaxYearAmt>
        <TotalAmt>32780</TotalAmt>
      </GrossInvestmentIncome170Grp>
      <TotalSupportAmt>114208</TotalSupportAmt>
      <First5Years170Ind>X</First5Years170Ind>
      <PublicSupportCY170Pct>0.71300</PublicSupportCY170Pct>
      <PublicSupportPY170Pct>0.82400</PublicSupportPY170Pct>
    </IRS990ScheduleA>
    <IRS990ScheduleO documentId="ScheduleO" documentName="IRS990ScheduleO">
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Part I, Line 10</FormAndLineReferenceDesc>
        <ExplanationTxt>Xeno Prize $7,000 - awarded to author of best paper published in Xenotransplantation journal; Agnes Azimzadeh Award $3,000 - award for significant contribution by a woman in xenotransplantation; Keith Reemtsma Award $5,000 - travel award to eminent scientist to share his/her research findings at biennial congress; David KC Cooper Young Investigator Award $2,500 - travel award to young scientist to share research findings at biennial congress; Scientific Awards - 5 travel awards of $1,000 each to support young scientists to attend IXA meetings</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Part I, Line 16</FormAndLineReferenceDesc>
        <ExplanationTxt>Travel $7,316; Office Expenses $1,592</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Part I, Line 20</FormAndLineReferenceDesc>
        <ExplanationTxt>Other changes in net assets or fund balances: Change in Market Value of Investments $5,278</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Part II, Line 24</FormAndLineReferenceDesc>
        <ExplanationTxt>Other Assets: Receivable for biennial congress surplus $29,069; for memberships $8,640; for journal royalties $20,804</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Part II, Line 26</FormAndLineReferenceDesc>
        <ExplanationTxt>Total Liabilities: Payable for various office expenses $8,339; Payable to publisher for member online access $11,100; deferred memberships $5,970; deferred meeting sponsorships $27,728; management fees payable $6,641</ExplanationTxt>
      </SupplementalInformationDetail>
    </IRS990ScheduleO>
  </ReturnData>
</Return>