<?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="2021v4.2">
  <ReturnHeader binaryAttachmentCnt="0">
    <ReturnTs>2022-11-04T15:38:00-05:00</ReturnTs>
    <TaxPeriodEndDt>2021-12-31</TaxPeriodEndDt>
    <PreparerFirmGrp>
      <PreparerFirmEIN>410746749</PreparerFirmEIN>
      <PreparerFirmName>
        <BusinessNameLine1Txt>CLIFTONLARSONALLEN LLP</BusinessNameLine1Txt>
      </PreparerFirmName>
      <PreparerUSAddress>
        <AddressLine1Txt>1301 WEST 22ND STREET SUITE 1100</AddressLine1Txt>
        <CityNm>OAK BROOK</CityNm>
        <StateAbbreviationCd>IL</StateAbbreviationCd>
        <ZIPCd>60523</ZIPCd>
      </PreparerUSAddress>
    </PreparerFirmGrp>
    <ReturnTypeCd>990</ReturnTypeCd>
    <TaxPeriodBeginDt>2021-01-01</TaxPeriodBeginDt>
    <Filer>
      <EIN>364290294</EIN>
      <BusinessName>
        <BusinessNameLine1Txt>CTSNET INC</BusinessNameLine1Txt>
      </BusinessName>
      <BusinessNameControlTxt>CTSN</BusinessNameControlTxt>
      <PhoneNum>3122025848</PhoneNum>
      <USAddress>
        <AddressLine1Txt>633 N SAINT CLAIR STREET 2100</AddressLine1Txt>
        <CityNm>CHICAGO</CityNm>
        <StateAbbreviationCd>IL</StateAbbreviationCd>
        <ZIPCd>60611</ZIPCd>
      </USAddress>
    </Filer>
    <BusinessOfficerGrp>
      <PersonNm>JOSEPH SABIK MD</PersonNm>
      <PersonTitleTxt>TREASURER</PersonTitleTxt>
      <PhoneNum>3122025848</PhoneNum>
      <SignatureDt>2022-11-01</SignatureDt>
      <DiscussWithPaidPreparerInd>1</DiscussWithPaidPreparerInd>
    </BusinessOfficerGrp>
    <SigningOfficerGrp>
      <PersonFullName>
        <PersonFirstNm>JOSEPH</PersonFirstNm>
        <PersonLastNm>SABIK MD</PersonLastNm>
      </PersonFullName>
      <SSN>999009999</SSN>
    </SigningOfficerGrp>
    <PreparerPersonGrp>
      <PreparerPersonNm>MELISSA STRUCK</PreparerPersonNm>
      <PTIN>P01310867</PTIN>
      <PhoneNum>6305738600</PhoneNum>
      <PreparationDt>2022-11-01</PreparationDt>
    </PreparerPersonGrp>
    <AdditionalFilerInformation>
      <TrustedCustomerGrp>
        <TrustedCustomerCd>3</TrustedCustomerCd>
        <AuthenticationAssuranceLevelCd>AAL1</AuthenticationAssuranceLevelCd>
        <IdentityAssuranceLevelCd>IAL1</IdentityAssuranceLevelCd>
      </TrustedCustomerGrp>
    </AdditionalFilerInformation>
    <TaxYr>2021</TaxYr>
    <BuildTS>2022-09-23 18:48:47Z</BuildTS>
  </ReturnHeader>
  <ReturnData documentCnt="5">
    <IRS990 documentId="RetDoc1038000001" referenceDocumentId="RetDoc1044400001">
      <PrincipalOfficerNm>JOSEPH SABIK MD</PrincipalOfficerNm>
      <USAddress>
        <AddressLine1Txt>633 N SAINT CLAIR STREET 2100</AddressLine1Txt>
        <CityNm>CHICAGO</CityNm>
        <StateAbbreviationCd>IL</StateAbbreviationCd>
        <ZIPCd>60611</ZIPCd>
      </USAddress>
      <GrossReceiptsAmt>2738265</GrossReceiptsAmt>
      <GroupReturnForAffiliatesInd>0</GroupReturnForAffiliatesInd>
      <Organization501cInd organization501cTypeTxt="6">X</Organization501cInd>
      <WebsiteAddressTxt>WWW.CTSNET.ORG</WebsiteAddressTxt>
      <TypeOfOrganizationCorpInd>X</TypeOfOrganizationCorpInd>
      <FormationYr>1999</FormationYr>
      <LegalDomicileStateCd>IL</LegalDomicileStateCd>
      <ActivityOrMissionDesc>CONNECT THE GLOBAL CARDIOTHORACIC COMMUNITY.</ActivityOrMissionDesc>
      <VotingMembersGoverningBodyCnt>10</VotingMembersGoverningBodyCnt>
      <VotingMembersIndependentCnt>10</VotingMembersIndependentCnt>
      <TotalEmployeeCnt>0</TotalEmployeeCnt>
      <TotalVolunteersCnt>30</TotalVolunteersCnt>
      <TotalGrossUBIAmt>57491</TotalGrossUBIAmt>
      <NetUnrelatedBusTxblIncmAmt>30279</NetUnrelatedBusTxblIncmAmt>
      <PYContributionsGrantsAmt>181179</PYContributionsGrantsAmt>
      <CYContributionsGrantsAmt>140653</CYContributionsGrantsAmt>
      <PYProgramServiceRevenueAmt>659850</PYProgramServiceRevenueAmt>
      <CYProgramServiceRevenueAmt>723326</CYProgramServiceRevenueAmt>
      <PYInvestmentIncomeAmt>38351</PYInvestmentIncomeAmt>
      <CYInvestmentIncomeAmt>319828</CYInvestmentIncomeAmt>
      <PYOtherRevenueAmt>0</PYOtherRevenueAmt>
      <CYOtherRevenueAmt>600</CYOtherRevenueAmt>
      <PYTotalRevenueAmt>879380</PYTotalRevenueAmt>
      <CYTotalRevenueAmt>1184407</CYTotalRevenueAmt>
      <PYGrantsAndSimilarPaidAmt>1000</PYGrantsAndSimilarPaidAmt>
      <CYGrantsAndSimilarPaidAmt>0</CYGrantsAndSimilarPaidAmt>
      <PYBenefitsPaidToMembersAmt>0</PYBenefitsPaidToMembersAmt>
      <CYBenefitsPaidToMembersAmt>0</CYBenefitsPaidToMembersAmt>
      <PYSalariesCompEmpBnftPaidAmt>0</PYSalariesCompEmpBnftPaidAmt>
      <CYSalariesCompEmpBnftPaidAmt>0</CYSalariesCompEmpBnftPaidAmt>
      <PYTotalProfFndrsngExpnsAmt>0</PYTotalProfFndrsngExpnsAmt>
      <CYTotalProfFndrsngExpnsAmt>0</CYTotalProfFndrsngExpnsAmt>
      <CYTotalFundraisingExpenseAmt>0</CYTotalFundraisingExpenseAmt>
      <PYOtherExpensesAmt>565810</PYOtherExpensesAmt>
      <CYOtherExpensesAmt>464823</CYOtherExpensesAmt>
      <PYTotalExpensesAmt>566810</PYTotalExpensesAmt>
      <CYTotalExpensesAmt>464823</CYTotalExpensesAmt>
      <PYRevenuesLessExpensesAmt>312570</PYRevenuesLessExpensesAmt>
      <CYRevenuesLessExpensesAmt>719584</CYRevenuesLessExpensesAmt>
      <TotalAssetsBOYAmt>3670453</TotalAssetsBOYAmt>
      <TotalAssetsEOYAmt>4452471</TotalAssetsEOYAmt>
      <TotalLiabilitiesBOYAmt>81084</TotalLiabilitiesBOYAmt>
      <TotalLiabilitiesEOYAmt>167432</TotalLiabilitiesEOYAmt>
      <NetAssetsOrFundBalancesBOYAmt>3589369</NetAssetsOrFundBalancesBOYAmt>
      <NetAssetsOrFundBalancesEOYAmt>4285039</NetAssetsOrFundBalancesEOYAmt>
      <MissionDesc>CONNECT THE GLOBAL CARDIOTHORACIC COMMUNITY.</MissionDesc>
      <SignificantNewProgramSrvcInd>0</SignificantNewProgramSrvcInd>
      <SignificantChangeInd>0</SignificantChangeInd>
      <Desc>PROVIDES VALUABLE EDUCATIONAL AND PROFESSIONAL WEB-BASED RESOURCES FOR A COMMUNITY OF OVER 50,300 CARDIOTHORACIC SURGEONS AND ALLIED HEALTH PROFESSIONALS INVOLVED IN THE CARDIOTHORACIC SURGERY SPECIALTY.</Desc>
      <ProgSrvcAccomActy2Grp>
        <Desc>PROVIDES MEETING PRESENTATION AND EVENT-POSTING SERVICES FOR OVER 30 CARDIOTHORACIC SURGERY PROFESSIONAL ORGANIZATIONS. WEBSITE INCLUDES SECTIONS ON EXPERT TECHNIQUES, SURGICAL VIDEOS, SURGEON PROFILES, MEDICAL JOURNALS, RESIDENT-FOCUSED CONTENT, AND SPECIALTY-RELATED EVENTS.</Desc>
      </ProgSrvcAccomActy2Grp>
      <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">1</ReportLandBuildingEquipmentInd>
      <ReportInvestmentsOtherSecInd referenceDocumentId="RetDoc1040000001">0</ReportInvestmentsOtherSecInd>
      <ReportProgramRelatedInvstInd referenceDocumentId="RetDoc1040000001">0</ReportProgramRelatedInvstInd>
      <ReportOtherAssetsInd referenceDocumentId="RetDoc1040000001">0</ReportOtherAssetsInd>
      <ReportOtherLiabilitiesInd referenceDocumentId="RetDoc1040000001">0</ReportOtherLiabilitiesInd>
      <IncludeFIN48FootnoteInd referenceDocumentId="RetDoc1040000001">0</IncludeFIN48FootnoteInd>
      <IndependentAuditFinclStmtInd referenceDocumentId="RetDoc1040000001">0</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>0</GrantsToOrganizationsInd>
      <GrantsToIndividualsInd>0</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>2</IRPDocumentCnt>
      <IRPDocumentW2GCnt>0</IRPDocumentW2GCnt>
      <EmployeeCnt>0</EmployeeCnt>
      <UnrelatedBusIncmOverLimitInd>1</UnrelatedBusIncmOverLimitInd>
      <Form990TFiledInd>1</Form990TFiledInd>
      <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>10</GoverningBodyVotingMembersCnt>
      <IndependentVotingMemberCnt>10</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>1</Form990ProvidedToGvrnBodyInd>
      <ConflictOfInterestPolicyInd>0</ConflictOfInterestPolicyInd>
      <WhistleblowerPolicyInd>0</WhistleblowerPolicyInd>
      <DocumentRetentionPolicyInd>0</DocumentRetentionPolicyInd>
      <CompensationProcessCEOInd>0</CompensationProcessCEOInd>
      <CompensationProcessOtherInd>0</CompensationProcessOtherInd>
      <InvestmentInJointVentureInd>0</InvestmentInJointVentureInd>
      <UponRequestInd>X</UponRequestInd>
      <BooksInCareOfDetail>
        <BusinessName>
          <BusinessNameLine1Txt>THE ORGANIZATION</BusinessNameLine1Txt>
        </BusinessName>
        <PhoneNum>3122025848</PhoneNum>
        <USAddress>
          <AddressLine1Txt>633 N SAINT CLAIR SUITE 2100</AddressLine1Txt>
          <CityNm>CHICAGO</CityNm>
          <StateAbbreviationCd>IL</StateAbbreviationCd>
          <ZIPCd>60611</ZIPCd>
        </USAddress>
      </BooksInCareOfDetail>
      <NoListedPersonsCompensatedInd>X</NoListedPersonsCompensatedInd>
      <Form990PartVIISectionAGrp>
        <PersonNm>DUKE E CAMERON MD</PersonNm>
        <TitleTxt>PRESIDENT</TitleTxt>
        <AverageHoursPerWeekRt>5.00</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <OfficerInd>X</OfficerInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>DOMENICO PAGANO MD</PersonNm>
        <TitleTxt>SECRETARY (THROUGH MAY 2021)</TitleTxt>
        <AverageHoursPerWeekRt>1.00</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <OfficerInd>X</OfficerInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>PATRICK O MYERS MD</PersonNm>
        <TitleTxt>SECRETARY (AFTER MAY 2021)</TitleTxt>
        <AverageHoursPerWeekRt>2.00</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <OfficerInd>X</OfficerInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>JOSEPH F SABIK MD</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>MARA B ANTONOFF MD</PersonNm>
        <TitleTxt>DIRECTOR</TitleTxt>
        <AverageHoursPerWeekRt>1.00</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>PAVAN ATLURI MD</PersonNm>
        <TitleTxt>DIRECTOR (THROUGH MAY 2021)</TitleTxt>
        <AverageHoursPerWeekRt>0.50</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>MARISA CEVASCO MD</PersonNm>
        <TitleTxt>DIRECTOR (AFTER MAY 2021)</TitleTxt>
        <AverageHoursPerWeekRt>0.50</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>W RANDOLPH CHITWOOD JR MD</PersonNm>
        <TitleTxt>DIRECTOR</TitleTxt>
        <AverageHoursPerWeekRt>1.00</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>DAVID T COOKE MD</PersonNm>
        <TitleTxt>DIRECTOR (THROUGH MAY 2021)</TitleTxt>
        <AverageHoursPerWeekRt>0.50</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>THOMAS K VARGHESE MD</PersonNm>
        <TitleTxt>DIRECTOR (AFTER MAY 2021)</TitleTxt>
        <AverageHoursPerWeekRt>0.50</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>BASEL RAMLAWI MD</PersonNm>
        <TitleTxt>DIRECTOR</TitleTxt>
        <AverageHoursPerWeekRt>1.00</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>J RAFAEL SADABA MD</PersonNm>
        <TitleTxt>DIRECTOR</TitleTxt>
        <AverageHoursPerWeekRt>1.00</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>MORITZ C WYLER VON BALLMOOS MD</PersonNm>
        <TitleTxt>DIRECTOR</TitleTxt>
        <AverageHoursPerWeekRt>1.00</AverageHoursPerWeekRt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>GRAHAME RUSH</PersonNm>
        <TitleTxt>EXECUTIVE DIRECTOR</TitleTxt>
        <AverageHoursPerWeekRt>3.00</AverageHoursPerWeekRt>
        <OfficerInd>X</OfficerInd>
        <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>THE SOCIETY OF THORACIC SURGEONS</BusinessNameLine1Txt>
          </BusinessName>
        </ContractorName>
        <ContractorAddress>
          <USAddress>
            <AddressLine1Txt>633 N SAINT CLAIR STREET SUITE 210</AddressLine1Txt>
            <CityNm>CHICAGO</CityNm>
            <StateAbbreviationCd>IL</StateAbbreviationCd>
            <ZIPCd>60611</ZIPCd>
          </USAddress>
        </ContractorAddress>
        <ServicesDesc>MANAGEMENT SERVICES</ServicesDesc>
        <CompensationAmt>383800</CompensationAmt>
      </ContractorCompensationGrp>
      <CntrctRcvdGreaterThan100KCnt>1</CntrctRcvdGreaterThan100KCnt>
      <AllOtherContributionsAmt>140653</AllOtherContributionsAmt>
      <TotalContributionsAmt>140653</TotalContributionsAmt>
      <ProgramServiceRevenueGrp>
        <Desc>WEB RESOURCES</Desc>
        <BusinessCd>900003</BusinessCd>
        <TotalRevenueColumnAmt>360903</TotalRevenueColumnAmt>
        <RelatedOrExemptFuncIncomeAmt>360903</RelatedOrExemptFuncIncomeAmt>
      </ProgramServiceRevenueGrp>
      <ProgramServiceRevenueGrp>
        <Desc>EDUCATION</Desc>
        <BusinessCd>900003</BusinessCd>
        <TotalRevenueColumnAmt>161721</TotalRevenueColumnAmt>
        <RelatedOrExemptFuncIncomeAmt>161721</RelatedOrExemptFuncIncomeAmt>
      </ProgramServiceRevenueGrp>
      <ProgramServiceRevenueGrp>
        <Desc>ADVERTISING</Desc>
        <BusinessCd>900003</BusinessCd>
        <TotalRevenueColumnAmt>105765</TotalRevenueColumnAmt>
        <RelatedOrExemptFuncIncomeAmt>48274</RelatedOrExemptFuncIncomeAmt>
        <UnrelatedBusinessRevenueAmt>57491</UnrelatedBusinessRevenueAmt>
      </ProgramServiceRevenueGrp>
      <ProgramServiceRevenueGrp>
        <Desc>ORGANIZATIONAL SUPPORT</Desc>
        <BusinessCd>900003</BusinessCd>
        <TotalRevenueColumnAmt>87552</TotalRevenueColumnAmt>
        <RelatedOrExemptFuncIncomeAmt>87552</RelatedOrExemptFuncIncomeAmt>
      </ProgramServiceRevenueGrp>
      <ProgramServiceRevenueGrp>
        <Desc>INDUSTRY FORUM</Desc>
        <BusinessCd>900003</BusinessCd>
        <TotalRevenueColumnAmt>6500</TotalRevenueColumnAmt>
        <RelatedOrExemptFuncIncomeAmt>6500</RelatedOrExemptFuncIncomeAmt>
      </ProgramServiceRevenueGrp>
      <TotalOthProgramServiceRevGrp>
        <TotalRevenueColumnAmt>885</TotalRevenueColumnAmt>
        <RelatedOrExemptFuncIncomeAmt>885</RelatedOrExemptFuncIncomeAmt>
      </TotalOthProgramServiceRevGrp>
      <TotalProgramServiceRevenueAmt>723326</TotalProgramServiceRevenueAmt>
      <InvestmentIncomeGrp>
        <TotalRevenueColumnAmt>80146</TotalRevenueColumnAmt>
        <ExclusionAmt>80146</ExclusionAmt>
      </InvestmentIncomeGrp>
      <GrossAmountSalesAssetsGrp>
        <SecuritiesAmt>1793540</SecuritiesAmt>
      </GrossAmountSalesAssetsGrp>
      <LessCostOthBasisSalesExpnssGrp>
        <SecuritiesAmt>1553858</SecuritiesAmt>
      </LessCostOthBasisSalesExpnssGrp>
      <GainOrLossGrp>
        <SecuritiesAmt>239682</SecuritiesAmt>
      </GainOrLossGrp>
      <NetGainOrLossInvestmentsGrp>
        <TotalRevenueColumnAmt>239682</TotalRevenueColumnAmt>
        <ExclusionAmt>239682</ExclusionAmt>
      </NetGainOrLossInvestmentsGrp>
      <OtherRevenueMiscGrp>
        <Desc>COPYRIGHTS</Desc>
        <BusinessCd>900003</BusinessCd>
        <TotalRevenueColumnAmt>600</TotalRevenueColumnAmt>
        <ExclusionAmt>600</ExclusionAmt>
      </OtherRevenueMiscGrp>
      <OtherRevenueTotalAmt>600</OtherRevenueTotalAmt>
      <TotalRevenueGrp>
        <TotalRevenueColumnAmt>1184407</TotalRevenueColumnAmt>
        <RelatedOrExemptFuncIncomeAmt>665835</RelatedOrExemptFuncIncomeAmt>
        <UnrelatedBusinessRevenueAmt>57491</UnrelatedBusinessRevenueAmt>
        <ExclusionAmt>320428</ExclusionAmt>
      </TotalRevenueGrp>
      <FeesForServicesManagementGrp>
        <TotalAmt>383800</TotalAmt>
      </FeesForServicesManagementGrp>
      <FeesForServicesLegalGrp>
        <TotalAmt>6</TotalAmt>
      </FeesForServicesLegalGrp>
      <FeesForServicesAccountingGrp>
        <TotalAmt>2965</TotalAmt>
      </FeesForServicesAccountingGrp>
      <FeesForSrvcInvstMgmntFeesGrp>
        <TotalAmt>15646</TotalAmt>
      </FeesForSrvcInvstMgmntFeesGrp>
      <FeesForServicesOtherGrp>
        <TotalAmt>8401</TotalAmt>
      </FeesForServicesOtherGrp>
      <AdvertisingGrp>
        <TotalAmt>1383</TotalAmt>
      </AdvertisingGrp>
      <OfficeExpensesGrp>
        <TotalAmt>6790</TotalAmt>
      </OfficeExpensesGrp>
      <InformationTechnologyGrp>
        <TotalAmt>41021</TotalAmt>
      </InformationTechnologyGrp>
      <DepreciationDepletionGrp>
        <TotalAmt>21055</TotalAmt>
      </DepreciationDepletionGrp>
      <InsuranceGrp>
        <TotalAmt>4680</TotalAmt>
      </InsuranceGrp>
      <OtherExpensesGrp>
        <Desc>STATE TAXES</Desc>
        <TotalAmt>623</TotalAmt>
      </OtherExpensesGrp>
      <OtherExpensesGrp>
        <Desc>CAREER FAIR EXPENSE</Desc>
        <TotalAmt>442</TotalAmt>
      </OtherExpensesGrp>
      <OtherExpensesGrp>
        <Desc>FEDERAL TAX REFUND</Desc>
        <TotalAmt>-23213</TotalAmt>
      </OtherExpensesGrp>
      <AllOtherExpensesGrp>
        <TotalAmt>1224</TotalAmt>
      </AllOtherExpensesGrp>
      <TotalFunctionalExpensesGrp>
        <TotalAmt>464823</TotalAmt>
      </TotalFunctionalExpensesGrp>
      <CashNonInterestBearingGrp>
        <BOYAmt>1042726</BOYAmt>
        <EOYAmt>976450</EOYAmt>
      </CashNonInterestBearingGrp>
      <AccountsReceivableGrp>
        <BOYAmt>73965</BOYAmt>
        <EOYAmt>225766</EOYAmt>
      </AccountsReceivableGrp>
      <PrepaidExpensesDefrdChargesGrp>
        <BOYAmt>42844</BOYAmt>
        <EOYAmt>40759</EOYAmt>
      </PrepaidExpensesDefrdChargesGrp>
      <LandBldgEquipCostOrOtherBssAmt>330860</LandBldgEquipCostOrOtherBssAmt>
      <LandBldgEquipAccumDeprecAmt>235450</LandBldgEquipAccumDeprecAmt>
      <LandBldgEquipBasisNetGrp>
        <BOYAmt>76465</BOYAmt>
        <EOYAmt>95410</EOYAmt>
      </LandBldgEquipBasisNetGrp>
      <InvestmentsPubTradedSecGrp>
        <BOYAmt>2434453</BOYAmt>
        <EOYAmt>3114086</EOYAmt>
      </InvestmentsPubTradedSecGrp>
      <TotalAssetsGrp>
        <BOYAmt>3670453</BOYAmt>
        <EOYAmt>4452471</EOYAmt>
      </TotalAssetsGrp>
      <AccountsPayableAccrExpnssGrp>
        <BOYAmt>3251</BOYAmt>
        <EOYAmt>2557</EOYAmt>
      </AccountsPayableAccrExpnssGrp>
      <DeferredRevenueGrp>
        <BOYAmt>77833</BOYAmt>
        <EOYAmt>164875</EOYAmt>
      </DeferredRevenueGrp>
      <TotalLiabilitiesGrp>
        <BOYAmt>81084</BOYAmt>
        <EOYAmt>167432</EOYAmt>
      </TotalLiabilitiesGrp>
      <OrgDoesNotFollowFASB117Ind>X</OrgDoesNotFollowFASB117Ind>
      <CapStkTrPrinCurrentFundsGrp>
        <BOYAmt>0</BOYAmt>
        <EOYAmt>0</EOYAmt>
      </CapStkTrPrinCurrentFundsGrp>
      <PdInCapSrplsLandBldgEqpFundGrp>
        <BOYAmt>0</BOYAmt>
        <EOYAmt>0</EOYAmt>
      </PdInCapSrplsLandBldgEqpFundGrp>
      <RtnEarnEndowmentIncmOthFndsGrp>
        <BOYAmt>3589369</BOYAmt>
        <EOYAmt>4285039</EOYAmt>
      </RtnEarnEndowmentIncmOthFndsGrp>
      <TotalNetAssetsFundBalanceGrp>
        <BOYAmt>3589369</BOYAmt>
        <EOYAmt>4285039</EOYAmt>
      </TotalNetAssetsFundBalanceGrp>
      <TotLiabNetAssetsFundBalanceGrp>
        <BOYAmt>3670453</BOYAmt>
        <EOYAmt>4452471</EOYAmt>
      </TotLiabNetAssetsFundBalanceGrp>
      <ReconcilationRevenueExpnssAmt>719584</ReconcilationRevenueExpnssAmt>
      <NetUnrlzdGainsLossesInvstAmt>-23914</NetUnrlzdGainsLossesInvstAmt>
      <OtherChangesInNetAssetsAmt>0</OtherChangesInNetAssetsAmt>
      <MethodOfAccountingAccrualInd>X</MethodOfAccountingAccrualInd>
      <AccountantCompileOrReviewInd>0</AccountantCompileOrReviewInd>
      <FSAuditedInd>0</FSAuditedInd>
      <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">
      <OtherLandBuildingsGrp>
        <OtherCostOrOtherBasisAmt>330860</OtherCostOrOtherBasisAmt>
        <DepreciationAmt>235450</DepreciationAmt>
        <BookValueAmt>95410</BookValueAmt>
      </OtherLandBuildingsGrp>
      <TotalBookValueLandBuildingsAmt>95410</TotalBookValueLandBuildingsAmt>
    </IRS990ScheduleD>
    <IRS990ScheduleO documentId="RetDoc1044400001">
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PART VI, SECTION A, LINE 3</FormAndLineReferenceDesc>
        <ExplanationTxt>PER A MANAGEMENT AGREEMENT BETWEEN BOTH PARTIES, CTSNET HAS RETAINED THE SOCIETY OF THORACIC SURGEONS (STS) TO PROVIDE ADMINISTRATIVE MANAGEMENT SERVICES AND TO PERFORM SUCH OTHER DUTIES AND SERVICES AS MAY BE ENTRUSTED TO STS BY CTSNET IN ACCORDANCE WITH CTSNET'S BYLAWS, ARTICLES OF INCORPORATION, RULES AND REGULATIONS AND BUDGET. THE STS OFFICE SERVES AS THE HEADQUARTERS FOR CTSNET. THE EMPLOYEES OF STS PROVIDE THESE SERVICES.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PART VI, SECTION A, LINE 6</FormAndLineReferenceDesc>
        <ExplanationTxt>CTSNET IS COMPRISED OF IT'S THREE FOUNDING MEMBERS: SOCIETY OF THORACIC SURGEONS (STS), AMERICAN ASSOCATION FOR THORACIC SURGERY (AATS), AND EUROPEAN ASSOCIATION FOR CARDIO-THORACIC SURGERY (EACTS). IN ADDITION, CTSNET HAS PARTICIPATION AGREEMENTS IN PLACE WITH OVER 30 CARDIOTHORACIC SURGERY PROFESSIONAL ORGANIZATIONS.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PART VI, SECTION A, LINE 7A</FormAndLineReferenceDesc>
        <ExplanationTxt>THE BOARD OF DIRECTORS IS COMPRISED OF TEN DIRECTORS WHICH ARE APPOINTED BY THE MEMBERS, FOUR BY STS, AND THREE EACH BY AATS AND EACTS. EACH DIRECTOR SHALL BE APPOINTED FOR A TWO YEAR TERM AND UNTIL HIS OR HER SUCCESSOR HAS BEEN APPOINTED AND QUALIFIED. THE OFFICERS (PRESIDENT, SECRETARY, AND TREASURER) ARE ELECTED BY AND FROM THE BOARD OF DIRECTORS. ONE REPRESENTATIVE FROM EACH MEMBER WILL SERVE THE OFFICES OF PRESIDENT, SECRETARY, AND TREASURER AT ALL TIMES, EXCEPT DURING PERIOD OF ANY UNFILLED VACANCIES.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PART VI, SECTION A, LINE 7B</FormAndLineReferenceDesc>
        <ExplanationTxt>THE GOVERNING BODY IS ENTIRELY MADE UP OF REPRESENTATIVES FROM EACH OF THE THREE MEMBERS</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PART VI, SECTION B, LINE 11B</FormAndLineReferenceDesc>
        <ExplanationTxt>AN ELECTRONIC COPY OF FORM 990 IS PROVIDED TO THE BOARD OF DIRECTORS VIA EMAIL.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PART VI, SECTION C, LINE 19</FormAndLineReferenceDesc>
        <ExplanationTxt>THE FINANCIAL STATEMENTS AND ORGANIZATION'S GOVERNING DOCUMENTS ARE AVAILABLE UPON REQUEST.</ExplanationTxt>
      </SupplementalInformationDetail>
    </IRS990ScheduleO>
  </ReturnData>
</Return>
