﻿<?xml version="1.0" encoding="utf-8"?>
<Return xmlns="http://www.irs.gov/efile" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.irs.gov/efile" returnVersion="2024v5.2">
  <ReturnHeader binaryAttachmentCnt="0">
    <ReturnTs>2025-11-17T14:07:46-06:00</ReturnTs>
    <TaxPeriodEndDt>2024-12-31</TaxPeriodEndDt>
    <PreparerFirmGrp>
      <PreparerFirmName>
        <BusinessNameLine1Txt>GRASSI &amp; CO CPA'S PC</BusinessNameLine1Txt>
      </PreparerFirmName>
      <PreparerUSAddress>
        <AddressLine1Txt>6 OMNI WAY SUITE 201</AddressLine1Txt>
        <CityNm>CHELMSFORD</CityNm>
        <StateAbbreviationCd>MA</StateAbbreviationCd>
        <ZIPCd>01824</ZIPCd>
      </PreparerUSAddress>
    </PreparerFirmGrp>
    <ReturnTypeCd>990</ReturnTypeCd>
    <TaxPeriodBeginDt>2024-01-01</TaxPeriodBeginDt>
    <Filer>
      <EIN>363181838</EIN>
      <BusinessName>
        <BusinessNameLine1Txt>SOUTHERN THORACIC SURGICAL</BusinessNameLine1Txt>
        <BusinessNameLine2Txt>ASSOCIATION</BusinessNameLine2Txt>
      </BusinessName>
      <BusinessNameControlTxt>SOUT</BusinessNameControlTxt>
      <PhoneNum>9789278330</PhoneNum>
      <USAddress>
        <AddressLine1Txt>500 CUMMINGS CENTER 4400</AddressLine1Txt>
        <CityNm>BEVERLY</CityNm>
        <StateAbbreviationCd>MA</StateAbbreviationCd>
        <ZIPCd>01915</ZIPCd>
      </USAddress>
    </Filer>
    <BusinessOfficerGrp>
      <PersonNm>SHANDA BLACKMON</PersonNm>
      <PersonTitleTxt>TREASURER</PersonTitleTxt>
      <PhoneNum>9789278330</PhoneNum>
      <SignatureDt>2025-11-16</SignatureDt>
      <DiscussWithPaidPreparerInd>1</DiscussWithPaidPreparerInd>
    </BusinessOfficerGrp>
    <IRSResponsiblePrtyInfoCurrInd>1</IRSResponsiblePrtyInfoCurrInd>
    <PreparerPersonGrp>
      <PreparerPersonNm>BRENDAN E TOOLIN</PreparerPersonNm>
      <PTIN>P01323447</PTIN>
      <PhoneNum>9784522500</PhoneNum>
      <PreparationDt>2025-11-16</PreparationDt>
    </PreparerPersonGrp>
    <TaxYr>2024</TaxYr>
    <BuildTS>2025-03-06 01:10:19Z</BuildTS>
  </ReturnHeader>
  <ReturnData documentCnt="6">
    <IRS990 documentId="RetDoc1038000001" referenceDocumentId="RetDoc1044400001">
      <PrincipalOfficerNm>SHANDA BLACKMON</PrincipalOfficerNm>
      <USAddress>
        <AddressLine1Txt>500 CUMMINGS CENTER 4400</AddressLine1Txt>
        <CityNm>BEVERLY</CityNm>
        <StateAbbreviationCd>MA</StateAbbreviationCd>
        <ZIPCd>01915</ZIPCd>
      </USAddress>
      <GrossReceiptsAmt>1521436</GrossReceiptsAmt>
      <GroupReturnForAffiliatesInd>0</GroupReturnForAffiliatesInd>
      <Organization501cInd organization501cTypeTxt="6">X</Organization501cInd>
      <WebsiteAddressTxt>WWW.STSA.ORG</WebsiteAddressTxt>
      <TypeOfOrganizationCorpInd>X</TypeOfOrganizationCorpInd>
      <FormationYr>1954</FormationYr>
      <LegalDomicileStateCd>IL</LegalDomicileStateCd>
      <ActivityOrMissionDesc>TO ADVANCE PATIENT CARE, STRENGTHEN OUR CARDIOTHORACIC SURGERY COMMUNITY, AND ENGAGE OUR FAMILIES BY FOSTERING A CULTURE OF COLLEGIALITY AND LIFE BALANCE.</ActivityOrMissionDesc>
      <VotingMembersGoverningBodyCnt>12</VotingMembersGoverningBodyCnt>
      <VotingMembersIndependentCnt>12</VotingMembersIndependentCnt>
      <TotalEmployeeCnt>0</TotalEmployeeCnt>
      <TotalVolunteersCnt>80</TotalVolunteersCnt>
      <TotalGrossUBIAmt>0</TotalGrossUBIAmt>
      <NetUnrelatedBusTxblIncmAmt>0</NetUnrelatedBusTxblIncmAmt>
      <PYContributionsGrantsAmt>0</PYContributionsGrantsAmt>
      <CYContributionsGrantsAmt>11250</CYContributionsGrantsAmt>
      <PYProgramServiceRevenueAmt>828972</PYProgramServiceRevenueAmt>
      <CYProgramServiceRevenueAmt>778011</CYProgramServiceRevenueAmt>
      <PYInvestmentIncomeAmt>68411</PYInvestmentIncomeAmt>
      <CYInvestmentIncomeAmt>109045</CYInvestmentIncomeAmt>
      <PYOtherRevenueAmt>253302</PYOtherRevenueAmt>
      <CYOtherRevenueAmt>0</CYOtherRevenueAmt>
      <PYTotalRevenueAmt>1150685</PYTotalRevenueAmt>
      <CYTotalRevenueAmt>898306</CYTotalRevenueAmt>
      <PYGrantsAndSimilarPaidAmt>66591</PYGrantsAndSimilarPaidAmt>
      <CYGrantsAndSimilarPaidAmt>12996</CYGrantsAndSimilarPaidAmt>
      <PYBenefitsPaidToMembersAmt>0</PYBenefitsPaidToMembersAmt>
      <CYBenefitsPaidToMembersAmt>0</CYBenefitsPaidToMembersAmt>
      <PYSalariesCompEmpBnftPaidAmt>25000</PYSalariesCompEmpBnftPaidAmt>
      <CYSalariesCompEmpBnftPaidAmt>0</CYSalariesCompEmpBnftPaidAmt>
      <PYTotalProfFndrsngExpnsAmt>0</PYTotalProfFndrsngExpnsAmt>
      <CYTotalProfFndrsngExpnsAmt>0</CYTotalProfFndrsngExpnsAmt>
      <CYTotalFundraisingExpenseAmt>252</CYTotalFundraisingExpenseAmt>
      <PYOtherExpensesAmt>925006</PYOtherExpensesAmt>
      <CYOtherExpensesAmt>891062</CYOtherExpensesAmt>
      <PYTotalExpensesAmt>1016597</PYTotalExpensesAmt>
      <CYTotalExpensesAmt>904058</CYTotalExpensesAmt>
      <PYRevenuesLessExpensesAmt>134088</PYRevenuesLessExpensesAmt>
      <CYRevenuesLessExpensesAmt>-5752</CYRevenuesLessExpensesAmt>
      <TotalAssetsBOYAmt>3154743</TotalAssetsBOYAmt>
      <TotalAssetsEOYAmt>3085344</TotalAssetsEOYAmt>
      <TotalLiabilitiesBOYAmt>369107</TotalLiabilitiesBOYAmt>
      <TotalLiabilitiesEOYAmt>88829</TotalLiabilitiesEOYAmt>
      <NetAssetsOrFundBalancesBOYAmt>2785636</NetAssetsOrFundBalancesBOYAmt>
      <NetAssetsOrFundBalancesEOYAmt>2996515</NetAssetsOrFundBalancesEOYAmt>
      <MissionDesc>TO ADVANCE PATIENT CARE, STRENGTHEN OUR CARDIOTHORACIC SURGERY COMMUNITY, AND ENGAGE OUR FAMILIES BY FOSTERING A CULTURE OF COLLEGIALITY AND LIFE BALANCE.</MissionDesc>
      <SignificantNewProgramSrvcInd>0</SignificantNewProgramSrvcInd>
      <SignificantChangeInd>0</SignificantChangeInd>
      <ExpenseAmt>750324</ExpenseAmt>
      <Desc>ANNUAL MEETINGS AND EDUCATIONAL OPPORTUNITIES FOR MEMBERS TO GATHER AND DISCUSS NEW DEVELOPMENTS IN THE FIELD OF CARDIOTHORACIC AND CARDIOVASCULAR SURGERY AND SHARE IDEAS FOR IMPROVEMENTS.</Desc>
      <TotalProgramServiceExpensesAmt>750324</TotalProgramServiceExpensesAmt>
      <DescribedInSection501c3Ind>0</DescribedInSection501c3Ind>
      <ScheduleBRequiredInd referenceDocumentId="RetDoc1234500001">1</ScheduleBRequiredInd>
      <PoliticalCampaignActyInd referenceDocumentId="RetDoc1039700001">0</PoliticalCampaignActyInd>
      <SubjectToProxyTaxInd referenceDocumentId="RetDoc1039700001">1</SubjectToProxyTaxInd>
      <DonorAdvisedFundInd referenceDocumentId="RetDoc1040000001">0</DonorAdvisedFundInd>
      <ConservationEasementsInd referenceDocumentId="RetDoc1040000001">0</ConservationEasementsInd>
      <CollectionsOfArtInd referenceDocumentId="RetDoc1040000001">0</CollectionsOfArtInd>
      <CreditCounselingInd referenceDocumentId="RetDoc1040000001">0</CreditCounselingInd>
      <DonorRstrOrQuasiEndowmentsInd>0</DonorRstrOrQuasiEndowmentsInd>
      <ReportLandBuildingEquipmentInd referenceDocumentId="RetDoc1040000001">0</ReportLandBuildingEquipmentInd>
      <ReportInvestmentsOtherSecInd referenceDocumentId="RetDoc1040000001">0</ReportInvestmentsOtherSecInd>
      <ReportProgramRelatedInvstInd referenceDocumentId="RetDoc1040000001">0</ReportProgramRelatedInvstInd>
      <ReportOtherAssetsInd referenceDocumentId="RetDoc1040000001">0</ReportOtherAssetsInd>
      <ReportOtherLiabilitiesInd referenceDocumentId="RetDoc1040000001">0</ReportOtherLiabilitiesInd>
      <IncludeFIN48FootnoteInd referenceDocumentId="RetDoc1040000001">1</IncludeFIN48FootnoteInd>
      <IndependentAuditFinclStmtInd referenceDocumentId="RetDoc1040000001">1</IndependentAuditFinclStmtInd>
      <ConsolidatedAuditFinclStmtInd referenceDocumentId="RetDoc1040000001">0</ConsolidatedAuditFinclStmtInd>
      <SchoolOperatingInd>0</SchoolOperatingInd>
      <ForeignOfficeInd>0</ForeignOfficeInd>
      <ForeignActivitiesInd>0</ForeignActivitiesInd>
      <MoreThan5000KToOrgInd>0</MoreThan5000KToOrgInd>
      <MoreThan5000KToIndividualsInd>0</MoreThan5000KToIndividualsInd>
      <ProfessionalFundraisingInd>0</ProfessionalFundraisingInd>
      <FundraisingActivitiesInd>0</FundraisingActivitiesInd>
      <GamingActivitiesInd>0</GamingActivitiesInd>
      <OperateHospitalInd>0</OperateHospitalInd>
      <GrantsToOrganizationsInd referenceDocumentId="RetDoc1041900001">0</GrantsToOrganizationsInd>
      <GrantsToIndividualsInd referenceDocumentId="RetDoc1041900001">1</GrantsToIndividualsInd>
      <ScheduleJRequiredInd>0</ScheduleJRequiredInd>
      <TaxExemptBondsInd>0</TaxExemptBondsInd>
      <LoanOutstandingInd>0</LoanOutstandingInd>
      <GrantToRelatedPersonInd>0</GrantToRelatedPersonInd>
      <BusinessRlnWithOrgMemInd>0</BusinessRlnWithOrgMemInd>
      <BusinessRlnWithFamMemInd>0</BusinessRlnWithFamMemInd>
      <BusinessRlnWith35CtrlEntInd>0</BusinessRlnWith35CtrlEntInd>
      <DeductibleNonCashContriInd>0</DeductibleNonCashContriInd>
      <DeductibleArtContributionInd>0</DeductibleArtContributionInd>
      <TerminateOperationsInd>0</TerminateOperationsInd>
      <PartialLiquidationInd>0</PartialLiquidationInd>
      <DisregardedEntityInd>0</DisregardedEntityInd>
      <RelatedEntityInd>0</RelatedEntityInd>
      <RelatedOrganizationCtrlEntInd>0</RelatedOrganizationCtrlEntInd>
      <ActivitiesConductedPrtshpInd>0</ActivitiesConductedPrtshpInd>
      <ScheduleORequiredInd>1</ScheduleORequiredInd>
      <IRPDocumentCnt>5</IRPDocumentCnt>
      <IRPDocumentW2GCnt>0</IRPDocumentW2GCnt>
      <EmployeeCnt>0</EmployeeCnt>
      <UnrelatedBusIncmOverLimitInd>0</UnrelatedBusIncmOverLimitInd>
      <ForeignFinancialAccountInd>0</ForeignFinancialAccountInd>
      <ProhibitedTaxShelterTransInd>0</ProhibitedTaxShelterTransInd>
      <TaxablePartyNotificationInd>0</TaxablePartyNotificationInd>
      <NondeductibleContributionsInd>0</NondeductibleContributionsInd>
      <IndoorTanningServicesInd>0</IndoorTanningServicesInd>
      <SubjToTaxRmnrtnExPrchtPymtInd>0</SubjToTaxRmnrtnExPrchtPymtInd>
      <SubjectToExcsTaxNetInvstIncInd>0</SubjectToExcsTaxNetInvstIncInd>
      <InfoInScheduleOPartVIInd>X</InfoInScheduleOPartVIInd>
      <GoverningBodyVotingMembersCnt>12</GoverningBodyVotingMembersCnt>
      <IndependentVotingMemberCnt>12</IndependentVotingMemberCnt>
      <FamilyOrBusinessRlnInd>0</FamilyOrBusinessRlnInd>
      <DelegationOfMgmtDutiesInd>1</DelegationOfMgmtDutiesInd>
      <ChangeToOrgDocumentsInd>0</ChangeToOrgDocumentsInd>
      <MaterialDiversionOrMisuseInd>0</MaterialDiversionOrMisuseInd>
      <MembersOrStockholdersInd>1</MembersOrStockholdersInd>
      <ElectionOfBoardMembersInd>1</ElectionOfBoardMembersInd>
      <DecisionsSubjectToApprovaInd>1</DecisionsSubjectToApprovaInd>
      <MinutesOfGoverningBodyInd>1</MinutesOfGoverningBodyInd>
      <MinutesOfCommitteesInd>1</MinutesOfCommitteesInd>
      <OfficerMailingAddressInd>0</OfficerMailingAddressInd>
      <LocalChaptersInd>0</LocalChaptersInd>
      <Form990ProvidedToGvrnBodyInd>0</Form990ProvidedToGvrnBodyInd>
      <ConflictOfInterestPolicyInd>1</ConflictOfInterestPolicyInd>
      <AnnualDisclosureCoveredPrsnInd>1</AnnualDisclosureCoveredPrsnInd>
      <RegularMonitoringEnfrcInd>1</RegularMonitoringEnfrcInd>
      <WhistleblowerPolicyInd>1</WhistleblowerPolicyInd>
      <DocumentRetentionPolicyInd>1</DocumentRetentionPolicyInd>
      <CompensationProcessCEOInd>0</CompensationProcessCEOInd>
      <CompensationProcessOtherInd>0</CompensationProcessOtherInd>
      <InvestmentInJointVentureInd>0</InvestmentInJointVentureInd>
      <UponRequestInd>X</UponRequestInd>
      <BooksInCareOfDetail>
        <BusinessName>
          <BusinessNameLine1Txt>PRRI</BusinessNameLine1Txt>
        </BusinessName>
        <PhoneNum>9789278330</PhoneNum>
        <USAddress>
          <AddressLine1Txt>500 CUMMINGS CENTER STE 4400</AddressLine1Txt>
          <CityNm>BEVERLY</CityNm>
          <StateAbbreviationCd>MA</StateAbbreviationCd>
          <ZIPCd>01915</ZIPCd>
        </USAddress>
      </BooksInCareOfDetail>
      <NoListedPersonsCompensatedInd>X</NoListedPersonsCompensatedInd>
      <Form990PartVIISectionAGrp>
        <PersonNm>DANIEL L MILLER</PersonNm>
        <TitleTxt>COUNCIL CHAIR</TitleTxt>
        <AverageHoursPerWeekRt>3.00</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <OfficerInd>X</OfficerInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>STEPHEN C YANG</PersonNm>
        <TitleTxt>PRESIDENT</TitleTxt>
        <AverageHoursPerWeekRt>1.50</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <OfficerInd>X</OfficerInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>MELANIE EDWARDS</PersonNm>
        <TitleTxt>PRESIDENT-ELECT</TitleTxt>
        <AverageHoursPerWeekRt>1.50</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <OfficerInd>X</OfficerInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>SCOTT LEMAIRE</PersonNm>
        <TitleTxt>SECOND VICE PRESIDENT</TitleTxt>
        <AverageHoursPerWeekRt>0.50</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <OfficerInd>X</OfficerInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>SHANDA BLACKMON</PersonNm>
        <TitleTxt>TREASURER</TitleTxt>
        <AverageHoursPerWeekRt>3.00</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <OfficerInd>X</OfficerInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>GORAV AILAWADI</PersonNm>
        <TitleTxt>TREASURER-ELECT</TitleTxt>
        <AverageHoursPerWeekRt>0.50</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <OfficerInd>X</OfficerInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>LEORA YARBORO</PersonNm>
        <TitleTxt>SECRETARY</TitleTxt>
        <AverageHoursPerWeekRt>0.50</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <OfficerInd>X</OfficerInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>DANIELA MOLENA</PersonNm>
        <TitleTxt>DIRECTOR OF CME</TitleTxt>
        <AverageHoursPerWeekRt>0.50</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>GUS MAVROUDIS</PersonNm>
        <TitleTxt>HISTORIAN</TitleTxt>
        <AverageHoursPerWeekRt>0.50</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>MARK BLEIWEIS</PersonNm>
        <TitleTxt>COUNCILOR-AT-LARGE</TitleTxt>
        <AverageHoursPerWeekRt>0.50</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>CHAD HUGHES</PersonNm>
        <TitleTxt>COUNCILOR-AT-LARGE</TitleTxt>
        <AverageHoursPerWeekRt>0.50</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>OURANIA PREVENTZA</PersonNm>
        <TitleTxt>COUNCILOR-AT-LARGE</TitleTxt>
        <AverageHoursPerWeekRt>0.50</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <TotalReportableCompFromOrgAmt>0</TotalReportableCompFromOrgAmt>
      <TotReportableCompRltdOrgAmt>0</TotReportableCompRltdOrgAmt>
      <TotalOtherCompensationAmt>0</TotalOtherCompensationAmt>
      <IndivRcvdGreaterThan100KCnt>0</IndivRcvdGreaterThan100KCnt>
      <FormerOfcrEmployeesListedInd>0</FormerOfcrEmployeesListedInd>
      <TotalCompGreaterThan150KInd>0</TotalCompGreaterThan150KInd>
      <CompensationFromOtherSrcsInd>0</CompensationFromOtherSrcsInd>
      <ContractorCompensationGrp>
        <ContractorName>
          <BusinessName>
            <BusinessNameLine1Txt>PRRI</BusinessNameLine1Txt>
          </BusinessName>
        </ContractorName>
        <ContractorAddress>
          <USAddress>
            <AddressLine1Txt>500 CUMMINGS CENTER STE 4400</AddressLine1Txt>
            <CityNm>BEVERLY</CityNm>
            <StateAbbreviationCd>MA</StateAbbreviationCd>
            <ZIPCd>01915</ZIPCd>
          </USAddress>
        </ContractorAddress>
        <ServicesDesc>MANAGEMENT</ServicesDesc>
        <CompensationAmt>220000</CompensationAmt>
      </ContractorCompensationGrp>
      <CntrctRcvdGreaterThan100KCnt>1</CntrctRcvdGreaterThan100KCnt>
      <AllOtherContributionsAmt>11250</AllOtherContributionsAmt>
      <TotalContributionsAmt>11250</TotalContributionsAmt>
      <ProgramServiceRevenueGrp>
        <Desc>ANNUAL MEETING</Desc>
        <BusinessCd>900099</BusinessCd>
        <TotalRevenueColumnAmt>598161</TotalRevenueColumnAmt>
        <RelatedOrExemptFuncIncomeAmt>598161</RelatedOrExemptFuncIncomeAmt>
      </ProgramServiceRevenueGrp>
      <ProgramServiceRevenueGrp>
        <Desc>MEMBERSHIP DUES</Desc>
        <BusinessCd>900099</BusinessCd>
        <TotalRevenueColumnAmt>179850</TotalRevenueColumnAmt>
        <RelatedOrExemptFuncIncomeAmt>179850</RelatedOrExemptFuncIncomeAmt>
      </ProgramServiceRevenueGrp>
      <TotalProgramServiceRevenueAmt>778011</TotalProgramServiceRevenueAmt>
      <InvestmentIncomeGrp>
        <TotalRevenueColumnAmt>67095</TotalRevenueColumnAmt>
        <ExclusionAmt>67095</ExclusionAmt>
      </InvestmentIncomeGrp>
      <GrossAmountSalesAssetsGrp>
        <SecuritiesAmt>665080</SecuritiesAmt>
      </GrossAmountSalesAssetsGrp>
      <LessCostOthBasisSalesExpnssGrp>
        <SecuritiesAmt>623130</SecuritiesAmt>
      </LessCostOthBasisSalesExpnssGrp>
      <GainOrLossGrp>
        <SecuritiesAmt>41950</SecuritiesAmt>
      </GainOrLossGrp>
      <NetGainOrLossInvestmentsGrp>
        <TotalRevenueColumnAmt>41950</TotalRevenueColumnAmt>
        <ExclusionAmt>41950</ExclusionAmt>
      </NetGainOrLossInvestmentsGrp>
      <TotalRevenueGrp>
        <TotalRevenueColumnAmt>898306</TotalRevenueColumnAmt>
        <RelatedOrExemptFuncIncomeAmt>778011</RelatedOrExemptFuncIncomeAmt>
        <UnrelatedBusinessRevenueAmt>0</UnrelatedBusinessRevenueAmt>
        <ExclusionAmt>109045</ExclusionAmt>
      </TotalRevenueGrp>
      <GrantsToDomesticIndividualsGrp>
        <TotalAmt>12996</TotalAmt>
        <ProgramServicesAmt>12996</ProgramServicesAmt>
      </GrantsToDomesticIndividualsGrp>
      <FeesForServicesManagementGrp>
        <TotalAmt>220000</TotalAmt>
        <ProgramServicesAmt>132566</ProgramServicesAmt>
        <ManagementAndGeneralAmt>87182</ManagementAndGeneralAmt>
        <FundraisingAmt>252</FundraisingAmt>
      </FeesForServicesManagementGrp>
      <FeesForServicesAccountingGrp>
        <TotalAmt>16493</TotalAmt>
        <ManagementAndGeneralAmt>16493</ManagementAndGeneralAmt>
      </FeesForServicesAccountingGrp>
      <FeesForSrvcInvstMgmntFeesGrp>
        <TotalAmt>16579</TotalAmt>
        <ManagementAndGeneralAmt>16579</ManagementAndGeneralAmt>
      </FeesForSrvcInvstMgmntFeesGrp>
      <OfficeExpensesGrp>
        <TotalAmt>20342</TotalAmt>
        <ManagementAndGeneralAmt>20342</ManagementAndGeneralAmt>
      </OfficeExpensesGrp>
      <InformationTechnologyGrp>
        <TotalAmt>8604</TotalAmt>
        <ManagementAndGeneralAmt>8604</ManagementAndGeneralAmt>
      </InformationTechnologyGrp>
      <ConferencesMeetingsGrp>
        <TotalAmt>560983</TotalAmt>
        <ProgramServicesAmt>560983</ProgramServicesAmt>
      </ConferencesMeetingsGrp>
      <InsuranceGrp>
        <TotalAmt>4282</TotalAmt>
        <ManagementAndGeneralAmt>4282</ManagementAndGeneralAmt>
      </InsuranceGrp>
      <OtherExpensesGrp>
        <Desc>OFFICERS AND COMMITTEES</Desc>
        <TotalAmt>40129</TotalAmt>
        <ProgramServicesAmt>40129</ProgramServicesAmt>
      </OtherExpensesGrp>
      <OtherExpensesGrp>
        <Desc>PUBLICATION</Desc>
        <TotalAmt>2461</TotalAmt>
        <ProgramServicesAmt>2461</ProgramServicesAmt>
      </OtherExpensesGrp>
      <OtherExpensesGrp>
        <Desc>BROOKS SCHOLARSHIP PINS</Desc>
        <TotalAmt>1189</TotalAmt>
        <ProgramServicesAmt>1189</ProgramServicesAmt>
      </OtherExpensesGrp>
      <TotalFunctionalExpensesGrp>
        <TotalAmt>904058</TotalAmt>
        <ProgramServicesAmt>750324</ProgramServicesAmt>
        <ManagementAndGeneralAmt>153482</ManagementAndGeneralAmt>
        <FundraisingAmt>252</FundraisingAmt>
      </TotalFunctionalExpensesGrp>
      <CashNonInterestBearingGrp>
        <BOYAmt>425515</BOYAmt>
        <EOYAmt>143218</EOYAmt>
      </CashNonInterestBearingGrp>
      <SavingsAndTempCashInvstGrp>
        <BOYAmt>59804</BOYAmt>
      </SavingsAndTempCashInvstGrp>
      <AccountsReceivableGrp>
        <BOYAmt>21591</BOYAmt>
        <EOYAmt>36545</EOYAmt>
      </AccountsReceivableGrp>
      <PrepaidExpensesDefrdChargesGrp>
        <BOYAmt>22006</BOYAmt>
        <EOYAmt>10852</EOYAmt>
      </PrepaidExpensesDefrdChargesGrp>
      <InvestmentsPubTradedSecGrp>
        <BOYAmt>2625827</BOYAmt>
        <EOYAmt>2894729</EOYAmt>
      </InvestmentsPubTradedSecGrp>
      <TotalAssetsGrp>
        <BOYAmt>3154743</BOYAmt>
        <EOYAmt>3085344</EOYAmt>
      </TotalAssetsGrp>
      <AccountsPayableAccrExpnssGrp>
        <BOYAmt>285794</BOYAmt>
        <EOYAmt>5957</EOYAmt>
      </AccountsPayableAccrExpnssGrp>
      <GrantsPayableGrp>
        <BOYAmt>80613</BOYAmt>
        <EOYAmt>82872</EOYAmt>
      </GrantsPayableGrp>
      <DeferredRevenueGrp>
        <BOYAmt>2700</BOYAmt>
      </DeferredRevenueGrp>
      <TotalLiabilitiesGrp>
        <BOYAmt>369107</BOYAmt>
        <EOYAmt>88829</EOYAmt>
      </TotalLiabilitiesGrp>
      <OrganizationFollowsFASB117Ind>X</OrganizationFollowsFASB117Ind>
      <NoDonorRestrictionNetAssetsGrp>
        <BOYAmt>2769709</BOYAmt>
        <EOYAmt>2978463</EOYAmt>
      </NoDonorRestrictionNetAssetsGrp>
      <DonorRestrictionNetAssetsGrp>
        <BOYAmt>15927</BOYAmt>
        <EOYAmt>18052</EOYAmt>
      </DonorRestrictionNetAssetsGrp>
      <TotalNetAssetsFundBalanceGrp>
        <BOYAmt>2785636</BOYAmt>
        <EOYAmt>2996515</EOYAmt>
      </TotalNetAssetsFundBalanceGrp>
      <TotLiabNetAssetsFundBalanceGrp>
        <BOYAmt>3154743</BOYAmt>
        <EOYAmt>3085344</EOYAmt>
      </TotLiabNetAssetsFundBalanceGrp>
      <ReconcilationRevenueExpnssAmt>-5752</ReconcilationRevenueExpnssAmt>
      <NetUnrlzdGainsLossesInvstAmt>216631</NetUnrlzdGainsLossesInvstAmt>
      <OtherChangesInNetAssetsAmt>0</OtherChangesInNetAssetsAmt>
      <MethodOfAccountingAccrualInd>X</MethodOfAccountingAccrualInd>
      <AccountantCompileOrReviewInd>0</AccountantCompileOrReviewInd>
      <FSAuditedInd>1</FSAuditedInd>
      <FSAuditedBasisGrp>
        <SeparateBasisFinclStmtInd>X</SeparateBasisFinclStmtInd>
      </FSAuditedBasisGrp>
      <AuditCommitteeInd>1</AuditCommitteeInd>
      <FederalGrantAuditRequiredInd>0</FederalGrantAuditRequiredInd>
    </IRS990>
    <IRS990ScheduleB documentId="RetDoc1234500001">
      <ContributorInformationGrp>
        <ContributorNum>RESTRICTED</ContributorNum>
        <ContributorBusinessName>
          <BusinessNameLine1>RESTRICTED</BusinessNameLine1>
        </ContributorBusinessName>
        <ContributorUSAddress>
          <AddressLine1>RESTRICTED</AddressLine1>
          <AddressLine2>RESTRICTED</AddressLine2>
          <City>RESTRICTED</City>
          <State>RESTRICTED</State>
          <ZIPCode>RESTRICTED</ZIPCode>
        </ContributorUSAddress>
        <TotalContributionsAmt>RESTRICTED</TotalContributionsAmt>
      </ContributorInformationGrp>
    </IRS990ScheduleB>
    <IRS990ScheduleC documentId="RetDoc1039700001">
      <SubstantiallyAllDuesNondedInd>0</SubstantiallyAllDuesNondedInd>
      <OnlyInHouseLobbyingInd>1</OnlyInHouseLobbyingInd>
      <AgreeCarryoverPriorYearInd>0</AgreeCarryoverPriorYearInd>
    </IRS990ScheduleC>
    <IRS990ScheduleD documentId="RetDoc1040000001">
      <TotalBookValueLandBuildingsAmt>0</TotalBookValueLandBuildingsAmt>
      <FootnoteTextInd>X</FootnoteTextInd>
      <TotalRevEtcAuditedFinclStmtAmt>1098358</TotalRevEtcAuditedFinclStmtAmt>
      <NetUnrealizedGainsInvstAmt>216631</NetUnrealizedGainsInvstAmt>
      <RevenueNotReportedAmt>216631</RevenueNotReportedAmt>
      <RevenueSubtotalAmt>881727</RevenueSubtotalAmt>
      <InvestmentExpensesNotIncldAmt>16579</InvestmentExpensesNotIncldAmt>
      <RevenueNotReportedFinclStmtAmt>16579</RevenueNotReportedFinclStmtAmt>
      <TotalRevenuePerForm990Amt>898306</TotalRevenuePerForm990Amt>
      <TotExpnsEtcAuditedFinclStmtAmt>887479</TotExpnsEtcAuditedFinclStmtAmt>
      <ExpensesNotReportedAmt>0</ExpensesNotReportedAmt>
      <ExpensesSubtotalAmt>887479</ExpensesSubtotalAmt>
      <InvestmentExpensesNotIncld2Amt>16579</InvestmentExpensesNotIncld2Amt>
      <ExpensesNotRptFinclStmtAmt>16579</ExpensesNotRptFinclStmtAmt>
      <TotalExpensesPerForm990Amt>904058</TotalExpensesPerForm990Amt>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>PART X, LINE 2:</FormAndLineReferenceDesc>
        <ExplanationTxt>THE ASSOCIATION, INCORPORATED IN ILLINOIS AS A TAX-EXEMPT ENTITY, HAS BEEN GRANTED TAX-EXEMPT STATUS UNDER INTERNAL REVENUE CODE SECTION 501(C)(6), AND IS, THEREFORE, GENERALLY EXEMPT FROM FEDERAL AND STATE INCOME TAXES. ACCORDINGLY, NO PROVISION FOR INCOME TAXES HAS BEEN PROVIDED FOR IN THE ACCOMPANYING FINANCIAL STATEMENTS. ASC 740-10, "INCOME TAXES," REQUIRES THE ASSOCIATION TO EVALUATE AND DISCLOSE TAX POSITIONS THAT COULD HAVE AN EFFECT ON THE ASSOCIATION'S FINANCIAL STATEMENTS. THE ASSOCIATION REPORTS ITS ACTIVITIES TO THE INTERNAL REVENUE SERVICE ON AN ANNUAL BASIS. THIS INFORMATIONAL RETURN IS GENERALLY SUBJECT TO AUDIT AND REVIEW BY THE GOVERNMENTAL AGENCIES FOR A PERIOD OF THREE YEARS AFTER FILING. SUBSTANTIALLY ALL OF THE ASSOCIATION'S INCOME, EXPENDITURES AND ACTIVITIES RELATE TO ITS EXEMPT PURPOSE, THEREFORE, MANAGEMENT HAS DETERMINED THAT THE ASSOCIATION IS NOT SUBJECT TO MATERIAL UNRELATED BUSINESS INCOME TAXES AND WILL CONTINUE TO QUALIFY AS A TAX-EXEMPT NOT-FOR-PROFIT ENTITY.</ExplanationTxt>
      </SupplementalInformationDetail>
    </IRS990ScheduleD>
    <IRS990ScheduleI documentId="RetDoc1041900001">
      <GrantRecordsMaintainedInd>0</GrantRecordsMaintainedInd>
      <GrantsOtherAsstToIndivInUSGrp>
        <GrantTypeTxt>BROOKS &amp; RESIDENT SCHOLARSHIP</GrantTypeTxt>
        <RecipientCnt>4</RecipientCnt>
        <CashGrantAmt>7935</CashGrantAmt>
      </GrantsOtherAsstToIndivInUSGrp>
      <GrantsOtherAsstToIndivInUSGrp>
        <GrantTypeTxt>DIVERSITY SCHOLARSHIP</GrantTypeTxt>
        <RecipientCnt>1</RecipientCnt>
        <CashGrantAmt>2560</CashGrantAmt>
      </GrantsOtherAsstToIndivInUSGrp>
      <GrantsOtherAsstToIndivInUSGrp>
        <GrantTypeTxt>ABSTRACT AWARDS</GrantTypeTxt>
        <RecipientCnt>5</RecipientCnt>
        <CashGrantAmt>2500</CashGrantAmt>
      </GrantsOtherAsstToIndivInUSGrp>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>PART III</FormAndLineReferenceDesc>
        <ExplanationTxt>SCHOLARSHIP RECIPIENTS RECEIVE FUNDING TO ATTEND THE STSA ANNUAL MEETING AND BENEFIT FROM THE GUIDANCE OF STSA MEMBERS. ABSTRACT AWARDS ARE PRESENTED FOR AN OUTSTANDING PAPER.</ExplanationTxt>
      </SupplementalInformationDetail>
    </IRS990ScheduleI>
    <IRS990ScheduleO documentId="RetDoc1044400001">
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PART VI, SECTION A, LINE 3</FormAndLineReferenceDesc>
        <ExplanationTxt>THE PROFESSIONAL RELATIONS AND RESEARCH INSTITUTE (PRRI) OF BEVERLY, MASSACHUSETTS, MAINTAINS THE BOOKS AND RECORDS OF THE ORGANIZATION AND PERFORMS OTHER RELATED MANAGERIAL AND ADMINISTRATIVE FUNCTIONS FOR WHICH IT IS COMPENSATED.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PART VI, SECTION A, LINE 6</FormAndLineReferenceDesc>
        <ExplanationTxt>THE ORGANIZATION HAS MEMBERS. THERE ARE SIX (6) CATEGORIES OF MEMBERS:ACTIVE, SENIOR, CANDIDATE, PRE-CANDIDATE, ASSOCIATE, AND HONORARY MEMBER. MEMBERS SHALL BE INDIVIDUALS WHO SUPPORT THE PURPOSE OF THE ORGANIZATION AND WHO AGREE TO COMPLY WITH THE ORGANIZATION'S RULES AND REGULATIONS. ACTIVE AND SENIOR MEMBERS SHALL BE ENTITLED TO HOLD OFFICE AND SHALL HAVE VOTING PRIVILEGES. ACTIVE AND SENIOR MEMBERS MUST BE BOARD CERTIFIED BY THE AMERICAN BOARD OF THORACIC SURGERY OR ITS FOREIGN EQUIVALENT. ASSOCIATE MEMBERS INCLUDE SUPPORT STAFF FOR PRACTICING CARDIOTHORACIC SURGEONS INCLUDING, BUT NOT LIMITED TO, NURSES, NURSE PRACTITIONERS, PERFUSIONISTS, PHYSICIAN ASSISTANTS, AND RESEARCH STAFF. HONORARY MEMBERSHIP CAN BE BESTOWED UPON A WORTHY RECIPIENT UPON RECOMMENDATION OF THE COUNCIL AND RATIFICATION BY A TWO-THIRDS MAJORITY OF THE VOTES AT THE ANNUAL MEETING. HONORARY MEMBERS ARE WELCOMED AT ALL SCIENTIFIC AND BUSINESS MEETINGS OF THE ORGANIZATION, BUT HAVE NO OBLIGATIONS OR RESPONSIBILITIES IN THE ORGANIZATION. CANDIDATE MEMBERS MUST BE MATCHED OR ENROLLED IN A THORACIC SURGERY EDUCATIONAL PROGRAM ACCREDITED BY THE RESIDENCY REVIEW COMMITTEE FOR THORACIC SURGERY UNDER THE AUTHORITY OF THE ACCREDITATION COUNCIL FOR GRADUATE MEDICAL EDUCATION THAT IS WITHIN THE ORGANIZATION REGION PROVIDED FOR IN THE BYLAWS TO BE CLASSIFIED AS A CANDIDATE MEMBER. PRE-CANDIDATE MEMBERS MAY APPLY FOR MEMBERSHIP BY EXPRESSING A DESIRE TO ENTER THE FIELD OF CARDIOTHORACIC SURGERY. PRE-CANDIDATE MEMBERS MAY TRANSFER TO CANDIDATE MEMBER STATUS ONCE THEY HAVE MATCHED OR ENROLLED IN A THORACIC SURGERY EDUCATIONAL PROGRAM ACCREDITED BY THE RESIDENCY REVIEW COMMITTEE FOR THORACIC SURGERY UNDER THE AUTHORITY OF THE ACCREDITATION COUNCIL FOR GRADUATE MEDICAL EDUCATION THAT IS WITHIN THE ORGANIZATION REGION.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PART VI, SECTION A, LINE 7A</FormAndLineReferenceDesc>
        <ExplanationTxt>THE MEMBERS OF THE ORGANIZATION PARTICIPATE IN THE ELECTION OF OFFICERS.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PART VI, SECTION A, LINE 7B</FormAndLineReferenceDesc>
        <ExplanationTxt>THE MEMBERS OF THE ORGANIZATION CAN VOTE ON BYLAW CHANGES, APPROVE NEW MEMBERS AND THE SLATE OF NOMINATIONS FOR OFFICERS.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PART VI, SECTION B, LINE 11B</FormAndLineReferenceDesc>
        <ExplanationTxt>990 IS REVIEWED BY THE ADMINISTRATIVE STAFF OF THE MANAGERIAL COMPANY (PRRI) AND IS THEN PROVIDED TO THE TREASURER FOR FINAL REVIEW BEFORE IT IS FILED.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PART VI, SECTION B, LINE 12C</FormAndLineReferenceDesc>
        <ExplanationTxt>OFFICERS, COUNCILORS, AND OTHERS ARE ANNUALLY REQUIRED TO COMPLETE A CONFLICT OF INTEREST DISCLOSURE STATEMENT AS A REQUIREMENT OF SERVICE. THE STATEMENT ON THE ORGANIZATION DISCLOSURE POLICY AND GUIDELINES REGARDING CONFLICTS OF INTEREST IS READ AT THE BEGINNING OF EVERY EXECUTIVE COUNCIL, COMMITTEE, COUNCIL OPERATING BOARD, AND WORKFORCE MEETING. IF A CONFLICT OF INTEREST OR THE APPEARANCE OF A CONFLICT OF INTEREST EXISTS, THE PERSON WITH SUCH A CONFLICT MUST DISCLOSE THE RELATIONSHIP AND REFRAIN FROM VOTING ON THE MATTER. IF THE NATURE OF THE RELATIONSHIP SUGGESTS THAT HIS OR HER PRESENCE MAY BE DETRIMENTAL TO THE DISCUSSION, HE OR SHE MUST EXIT THE MEETING. THE MEETING CHAIR MAKES THE FINAL DETERMINATIONS TO THE APPROPRIATE ACTION.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PART VI, SECTION C, LINE 19</FormAndLineReferenceDesc>
        <ExplanationTxt>GOVERNING DOCUMENTS, CONFLICT OF INTEREST POLICY AND FINANCIAL STATEMENTS ARE AVAILABLE TO THE PUBLIC UPON REQUEST AT THE ADMINISTRATIVE OFFICES OF THE ORGANIZATION'S MANAGEMENT COMPANY (PRRI).</ExplanationTxt>
      </SupplementalInformationDetail>
    </IRS990ScheduleO>
  </ReturnData>
</Return>