﻿<?xml version="1.0" encoding="utf-8"?>
<Return xmlns="http://www.irs.gov/efile" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" returnVersion="2015v2.1">
  <ReturnHeader binaryAttachmentCnt="0">
    <ReturnTs>2016-07-06T14:19:05-05:00</ReturnTs>
    <TaxPeriodEndDt>2015-12-31</TaxPeriodEndDt>
    <PreparerFirmGrp>
      <PreparerFirmEIN>470806082</PreparerFirmEIN>
      <PreparerFirmName>
        <BusinessNameLine1Txt>HOCKING &amp; REID LLC</BusinessNameLine1Txt>
      </PreparerFirmName>
      <PreparerUSAddress>
        <AddressLine1Txt>5757 SO 34TH ST SUITE 100</AddressLine1Txt>
        <CityNm>LINCOLN</CityNm>
        <StateAbbreviationCd>NE</StateAbbreviationCd>
        <ZIPCd>68516</ZIPCd>
      </PreparerUSAddress>
    </PreparerFirmGrp>
    <ReturnTypeCd>990</ReturnTypeCd>
    <TaxPeriodBeginDt>2015-01-01</TaxPeriodBeginDt>
    <Filer>
      <EIN>521959601</EIN>
      <BusinessName>
        <BusinessNameLine1Txt>THE MASTOCYTOSIS SOCIETY INC</BusinessNameLine1Txt>
      </BusinessName>
      <BusinessNameControlTxt>MAST</BusinessNameControlTxt>
      <PhoneNum>4024633509</PhoneNum>
      <USAddress>
        <AddressLine1Txt>PO BOX 191752</AddressLine1Txt>
        <CityNm>ATLANTA</CityNm>
        <StateAbbreviationCd>GA</StateAbbreviationCd>
        <ZIPCd>31119</ZIPCd>
      </USAddress>
    </Filer>
    <BusinessOfficerGrp>
      <PersonNm>VALERIE SLEE</PersonNm>
      <PersonTitleTxt>CHAIRMAN/PRESIDENT</PersonTitleTxt>
      <PhoneNum>4024633509</PhoneNum>
      <SignatureDt>2016-07-05</SignatureDt>
      <DiscussWithPaidPreparerInd>true</DiscussWithPaidPreparerInd>
    </BusinessOfficerGrp>
    <PreparerPersonGrp>
      <PreparerPersonNm>SHAWN P SCHULENBERG</PreparerPersonNm>
      <PTIN>P00668147</PTIN>
      <PhoneNum>4024410140</PhoneNum>
      <PreparationDt>2016-07-06</PreparationDt>
    </PreparerPersonGrp>
    <TaxYr>2015</TaxYr>
    <BuildTS>2016-09-27 15:27:22Z</BuildTS>
  </ReturnHeader>
  <ReturnData documentCnt="7">
    <IRS990 documentId="RetDoc2" referenceDocumentId="RetDoc6">
      <AddressChangeInd>X</AddressChangeInd>
      <PrincipalOfficerNm>VALERIE SLEE</PrincipalOfficerNm>
      <GrossReceiptsAmt>162108</GrossReceiptsAmt>
      <GroupReturnForAffiliatesInd>false</GroupReturnForAffiliatesInd>
      <Organization501c3Ind>X</Organization501c3Ind>
      <WebsiteAddressTxt>WWW.TMSFORACURE.ORG</WebsiteAddressTxt>
      <TypeOfOrganizationCorpInd>X</TypeOfOrganizationCorpInd>
      <FormationYr>1994</FormationYr>
      <LegalDomicileStateCd>MD</LegalDomicileStateCd>
      <ActivityOrMissionDesc>THE MASTOCYTOSIS SOCITY IS A NONPROFIT ORGANIZATION DEDICATED TO SUPPORTING PATIENTS AFFECTED BY MASTOCYTOSIS/MAST CELL ACTIVATION DISORDERS AS WELL AS THEIR FAMILIES, CAREGIVERS AND PHYSICIANS THROUGH RESEARCH, EDUCATION AND ADVOCACY.</ActivityOrMissionDesc>
      <VotingMembersGoverningBodyCnt>5</VotingMembersGoverningBodyCnt>
      <VotingMembersIndependentCnt>5</VotingMembersIndependentCnt>
      <TotalEmployeeCnt>0</TotalEmployeeCnt>
      <TotalVolunteersCnt>135</TotalVolunteersCnt>
      <TotalGrossUBIAmt>35134</TotalGrossUBIAmt>
      <NetUnrelatedBusTxblIncmAmt>20776</NetUnrelatedBusTxblIncmAmt>
      <PYContributionsGrantsAmt>269276</PYContributionsGrantsAmt>
      <CYContributionsGrantsAmt>125267</CYContributionsGrantsAmt>
      <CYProgramServiceRevenueAmt>0</CYProgramServiceRevenueAmt>
      <PYInvestmentIncomeAmt>228</PYInvestmentIncomeAmt>
      <CYInvestmentIncomeAmt>256</CYInvestmentIncomeAmt>
      <PYOtherRevenueAmt>1376</PYOtherRevenueAmt>
      <CYOtherRevenueAmt>35134</CYOtherRevenueAmt>
      <PYTotalRevenueAmt>270880</PYTotalRevenueAmt>
      <CYTotalRevenueAmt>160657</CYTotalRevenueAmt>
      <PYGrantsAndSimilarPaidAmt>75000</PYGrantsAndSimilarPaidAmt>
      <CYGrantsAndSimilarPaidAmt>10000</CYGrantsAndSimilarPaidAmt>
      <CYBenefitsPaidToMembersAmt>0</CYBenefitsPaidToMembersAmt>
      <CYSalariesCompEmpBnftPaidAmt>0</CYSalariesCompEmpBnftPaidAmt>
      <CYTotalProfFndrsngExpnsAmt>0</CYTotalProfFndrsngExpnsAmt>
      <CYTotalFundraisingExpenseAmt>182</CYTotalFundraisingExpenseAmt>
      <PYOtherExpensesAmt>200925</PYOtherExpensesAmt>
      <CYOtherExpensesAmt>107596</CYOtherExpensesAmt>
      <PYTotalExpensesAmt>275925</PYTotalExpensesAmt>
      <CYTotalExpensesAmt>117596</CYTotalExpensesAmt>
      <PYRevenuesLessExpensesAmt>-5045</PYRevenuesLessExpensesAmt>
      <CYRevenuesLessExpensesAmt>43061</CYRevenuesLessExpensesAmt>
      <TotalAssetsBOYAmt>234136</TotalAssetsBOYAmt>
      <TotalAssetsEOYAmt>244808</TotalAssetsEOYAmt>
      <TotalLiabilitiesBOYAmt>37065</TotalLiabilitiesBOYAmt>
      <TotalLiabilitiesEOYAmt>4676</TotalLiabilitiesEOYAmt>
      <NetAssetsOrFundBalancesBOYAmt>197071</NetAssetsOrFundBalancesBOYAmt>
      <NetAssetsOrFundBalancesEOYAmt>240132</NetAssetsOrFundBalancesEOYAmt>
      <InfoInScheduleOPartIIIInd>X</InfoInScheduleOPartIIIInd>
      <MissionDesc>THE MASTOCYTOSIS SOCITY IS A NONPROFIT ORGANIZATION DEDICATED TO SUPPORTING PATIENTS AFFECTED BY MASTOCYTOSIS/MAST CELL ACTIVATION DISORDERS AS WELL AS THEIR FAMILIES, CAREGIVERS AND PHYSICIANS THROUGH RESEARCH, EDUCATION AND ADVOCACY.</MissionDesc>
      <SignificantNewProgramSrvcInd>false</SignificantNewProgramSrvcInd>
      <SignificantChangeInd>false</SignificantChangeInd>
      <ExpenseAmt>28804</ExpenseAmt>
      <GrantAmt>10000</GrantAmt>
      <Desc>THE ANNUAL MEETING BRING TOGETHER MEDICAL PROFESSIONALS AND MEMBERS TO LEARN HOW TO DEAL WITH THE MAST CELL ISSUE.</Desc>
      <ProgSrvcAccomActy3Grp>
        <ExpenseAmt>35404</ExpenseAmt>
        <Desc>HAVE REPRESENTATIVES PRESENTING INFORMATION TO PHYSICIANS ATTENDING AAAAI, ACAAI, PEDIATRIC AND ASH CONFERENCES</Desc>
      </ProgSrvcAccomActy3Grp>
      <ProgSrvcAccomActyOtherGrp>
        <ExpenseAmt>38477</ExpenseAmt>
        <Desc>PUBLICATIONS AND OTHER SUPPORT GROUP SUBSIDIES FOR PARTICIPANTS IN ANNUAL MEETINGS</Desc>
      </ProgSrvcAccomActyOtherGrp>
      <TotalOtherProgSrvcExpenseAmt>38477</TotalOtherProgSrvcExpenseAmt>
      <TotalProgramServiceExpensesAmt>102685</TotalProgramServiceExpensesAmt>
      <DescribedInSection501c3Ind referenceDocumentId="RetDoc7">true</DescribedInSection501c3Ind>
      <ScheduleBRequiredInd referenceDocumentId="RetDoc1">true</ScheduleBRequiredInd>
      <PoliticalCampaignActyInd>false</PoliticalCampaignActyInd>
      <LobbyingActivitiesInd>false</LobbyingActivitiesInd>
      <SubjectToProxyTaxInd>false</SubjectToProxyTaxInd>
      <DonorAdvisedFundInd referenceDocumentId="RetDoc3">false</DonorAdvisedFundInd>
      <ConservationEasementsInd referenceDocumentId="RetDoc3">false</ConservationEasementsInd>
      <CollectionsOfArtInd referenceDocumentId="RetDoc3">false</CollectionsOfArtInd>
      <CreditCounselingInd referenceDocumentId="RetDoc3">false</CreditCounselingInd>
      <TempOrPermanentEndowmentsInd referenceDocumentId="RetDoc3">false</TempOrPermanentEndowmentsInd>
      <ReportLandBuildingEquipmentInd referenceDocumentId="RetDoc3">false</ReportLandBuildingEquipmentInd>
      <ReportInvestmentsOtherSecInd referenceDocumentId="RetDoc3">false</ReportInvestmentsOtherSecInd>
      <ReportProgramRelatedInvstInd referenceDocumentId="RetDoc3">false</ReportProgramRelatedInvstInd>
      <ReportOtherAssetsInd referenceDocumentId="RetDoc3">false</ReportOtherAssetsInd>
      <ReportOtherLiabilitiesInd referenceDocumentId="RetDoc3">true</ReportOtherLiabilitiesInd>
      <IncludeFIN48FootnoteInd referenceDocumentId="RetDoc3">false</IncludeFIN48FootnoteInd>
      <IndependentAuditFinclStmtInd referenceDocumentId="RetDoc3">true</IndependentAuditFinclStmtInd>
      <ConsolidatedAuditFinclStmtInd referenceDocumentId="RetDoc3">false</ConsolidatedAuditFinclStmtInd>
      <SchoolOperatingInd>false</SchoolOperatingInd>
      <ForeignOfficeInd>false</ForeignOfficeInd>
      <ForeignActivitiesInd>false</ForeignActivitiesInd>
      <MoreThan5000KToOrgInd>false</MoreThan5000KToOrgInd>
      <MoreThan5000KToIndividualsInd>false</MoreThan5000KToIndividualsInd>
      <ProfessionalFundraisingInd referenceDocumentId="RetDoc4">false</ProfessionalFundraisingInd>
      <FundraisingActivitiesInd referenceDocumentId="RetDoc4">true</FundraisingActivitiesInd>
      <GamingActivitiesInd referenceDocumentId="RetDoc4">false</GamingActivitiesInd>
      <OperateHospitalInd>false</OperateHospitalInd>
      <GrantsToOrganizationsInd referenceDocumentId="RetDoc5">true</GrantsToOrganizationsInd>
      <GrantsToIndividualsInd referenceDocumentId="RetDoc5">false</GrantsToIndividualsInd>
      <ScheduleJRequiredInd>false</ScheduleJRequiredInd>
      <TaxExemptBondsInd>false</TaxExemptBondsInd>
      <EngagedInExcessBenefitTransInd>false</EngagedInExcessBenefitTransInd>
      <PYExcessBenefitTransInd>false</PYExcessBenefitTransInd>
      <LoanOutstandingInd>false</LoanOutstandingInd>
      <GrantToRelatedPersonInd>false</GrantToRelatedPersonInd>
      <BusinessRlnWithOrgMemInd>false</BusinessRlnWithOrgMemInd>
      <BusinessRlnWithFamMemInd>false</BusinessRlnWithFamMemInd>
      <BusinessRlnWithOfficerEntInd>false</BusinessRlnWithOfficerEntInd>
      <DeductibleNonCashContriInd>false</DeductibleNonCashContriInd>
      <DeductibleArtContributionInd>false</DeductibleArtContributionInd>
      <TerminateOperationsInd>false</TerminateOperationsInd>
      <PartialLiquidationInd>false</PartialLiquidationInd>
      <DisregardedEntityInd>false</DisregardedEntityInd>
      <RelatedEntityInd>false</RelatedEntityInd>
      <RelatedOrganizationCtrlEntInd>false</RelatedOrganizationCtrlEntInd>
      <TrnsfrExmptNonChrtblRltdOrgInd>false</TrnsfrExmptNonChrtblRltdOrgInd>
      <ActivitiesConductedPrtshpInd>false</ActivitiesConductedPrtshpInd>
      <ScheduleORequiredInd>true</ScheduleORequiredInd>
      <IRPDocumentCnt>3</IRPDocumentCnt>
      <IRPDocumentW2GCnt>0</IRPDocumentW2GCnt>
      <EmployeeCnt>0</EmployeeCnt>
      <UnrelatedBusIncmOverLimitInd>true</UnrelatedBusIncmOverLimitInd>
      <Form990TFiledInd>true</Form990TFiledInd>
      <ForeignFinancialAccountInd>false</ForeignFinancialAccountInd>
      <ProhibitedTaxShelterTransInd>false</ProhibitedTaxShelterTransInd>
      <TaxablePartyNotificationInd>false</TaxablePartyNotificationInd>
      <NondeductibleContributionsInd>false</NondeductibleContributionsInd>
      <IndoorTanningServicesInd>false</IndoorTanningServicesInd>
      <InfoInScheduleOPartVIInd>X</InfoInScheduleOPartVIInd>
      <GoverningBodyVotingMembersCnt>5</GoverningBodyVotingMembersCnt>
      <IndependentVotingMemberCnt>5</IndependentVotingMemberCnt>
      <FamilyOrBusinessRlnInd>false</FamilyOrBusinessRlnInd>
      <DelegationOfMgmtDutiesInd>false</DelegationOfMgmtDutiesInd>
      <ChangeToOrgDocumentsInd>false</ChangeToOrgDocumentsInd>
      <MaterialDiversionOrMisuseInd>false</MaterialDiversionOrMisuseInd>
      <MembersOrStockholdersInd>false</MembersOrStockholdersInd>
      <ElectionOfBoardMembersInd>true</ElectionOfBoardMembersInd>
      <DecisionsSubjectToApprovaInd>true</DecisionsSubjectToApprovaInd>
      <MinutesOfGoverningBodyInd>true</MinutesOfGoverningBodyInd>
      <MinutesOfCommitteesInd>true</MinutesOfCommitteesInd>
      <OfficerMailingAddressInd>false</OfficerMailingAddressInd>
      <LocalChaptersInd>false</LocalChaptersInd>
      <Form990ProvidedToGvrnBodyInd>true</Form990ProvidedToGvrnBodyInd>
      <ConflictOfInterestPolicyInd>true</ConflictOfInterestPolicyInd>
      <AnnualDisclosureCoveredPrsnInd>true</AnnualDisclosureCoveredPrsnInd>
      <RegularMonitoringEnfrcInd>true</RegularMonitoringEnfrcInd>
      <WhistleblowerPolicyInd>false</WhistleblowerPolicyInd>
      <DocumentRetentionPolicyInd>false</DocumentRetentionPolicyInd>
      <CompensationProcessCEOInd>true</CompensationProcessCEOInd>
      <CompensationProcessOtherInd>true</CompensationProcessOtherInd>
      <InvestmentInJointVentureInd>false</InvestmentInJointVentureInd>
      <StatesWhereCopyOfReturnIsFldCd>MD</StatesWhereCopyOfReturnIsFldCd>
      <UponRequestInd>X</UponRequestInd>
      <BooksInCareOfDetail>
        <PersonNm>STEPHEN REY</PersonNm>
        <PhoneNum>5088423080</PhoneNum>
        <USAddress>
          <AddressLine1Txt>93 PRESCOTT RD</AddressLine1Txt>
          <CityNm>BOXBOROUGH</CityNm>
          <StateAbbreviationCd>MA</StateAbbreviationCd>
          <ZIPCd>01719</ZIPCd>
        </USAddress>
      </BooksInCareOfDetail>
      <NoListedPersonsCompensatedInd>X</NoListedPersonsCompensatedInd>
      <Form990PartVIISectionAGrp>
        <PersonNm>VALERIE SLEE</PersonNm>
        <TitleTxt>CHAIRMAN/PRE</TitleTxt>
        <OfficerInd>X</OfficerInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>MARITA BARLOW</PersonNm>
        <TitleTxt>VICE-CHAIR/V</TitleTxt>
        <OfficerInd>X</OfficerInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>MISHELE CUNNINGHAM</PersonNm>
        <TitleTxt>DIRECTOR</TitleTxt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>PATRICIA BEGGIATO</PersonNm>
        <TitleTxt>DIRECTOR</TitleTxt>
        <IndividualTrusteeOrDirectorInd>X</IndividualTrusteeOrDirectorInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <Form990PartVIISectionAGrp>
        <PersonNm>GAIL BARBARA</PersonNm>
        <TitleTxt>SECRETARY</TitleTxt>
        <OfficerInd>X</OfficerInd>
        <ReportableCompFromOrgAmt>0</ReportableCompFromOrgAmt>
        <ReportableCompFromRltdOrgAmt>0</ReportableCompFromRltdOrgAmt>
        <OtherCompensationAmt>0</OtherCompensationAmt>
      </Form990PartVIISectionAGrp>
      <FormerOfcrEmployeesListedInd>false</FormerOfcrEmployeesListedInd>
      <TotalCompGreaterThan150KInd>false</TotalCompGreaterThan150KInd>
      <CompensationFromOtherSrcsInd>false</CompensationFromOtherSrcsInd>
      <MembershipDuesAmt>27220</MembershipDuesAmt>
      <FundraisingAmt>32624</FundraisingAmt>
      <AllOtherContributionsAmt>65423</AllOtherContributionsAmt>
      <TotalContributionsAmt>125267</TotalContributionsAmt>
      <InvestmentIncomeGrp>
        <TotalRevenueColumnAmt>256</TotalRevenueColumnAmt>
        <RelatedOrExemptFuncIncomeAmt>256</RelatedOrExemptFuncIncomeAmt>
      </InvestmentIncomeGrp>
      <ContriRptFundraisingEventAmt>32624</ContriRptFundraisingEventAmt>
      <GrossSalesOfInventoryAmt>36585</GrossSalesOfInventoryAmt>
      <CostOfGoodsSoldAmt>1451</CostOfGoodsSoldAmt>
      <NetIncomeOrLossGrp>
        <TotalRevenueColumnAmt>35134</TotalRevenueColumnAmt>
        <UnrelatedBusinessRevenueAmt>35134</UnrelatedBusinessRevenueAmt>
      </NetIncomeOrLossGrp>
      <TotalRevenueGrp>
        <TotalRevenueColumnAmt>160657</TotalRevenueColumnAmt>
        <RelatedOrExemptFuncIncomeAmt>256</RelatedOrExemptFuncIncomeAmt>
        <UnrelatedBusinessRevenueAmt>35134</UnrelatedBusinessRevenueAmt>
      </TotalRevenueGrp>
      <GrantsToDomesticOrgsGrp>
        <TotalAmt>10000</TotalAmt>
        <ProgramServicesAmt>10000</ProgramServicesAmt>
      </GrantsToDomesticOrgsGrp>
      <FeesForServicesAccountingGrp>
        <TotalAmt>2850</TotalAmt>
        <ManagementAndGeneralAmt>2850</ManagementAndGeneralAmt>
      </FeesForServicesAccountingGrp>
      <FeesForServicesOtherGrp>
        <TotalAmt>700</TotalAmt>
        <ManagementAndGeneralAmt>700</ManagementAndGeneralAmt>
      </FeesForServicesOtherGrp>
      <OfficeExpensesGrp>
        <TotalAmt>7687</TotalAmt>
        <ManagementAndGeneralAmt>7687</ManagementAndGeneralAmt>
      </OfficeExpensesGrp>
      <InformationTechnologyGrp>
        <TotalAmt>16766</TotalAmt>
        <ProgramServicesAmt>16766</ProgramServicesAmt>
      </InformationTechnologyGrp>
      <ConferencesMeetingsGrp>
        <TotalAmt>35404</TotalAmt>
        <ProgramServicesAmt>35404</ProgramServicesAmt>
      </ConferencesMeetingsGrp>
      <InsuranceGrp>
        <TotalAmt>1607</TotalAmt>
        <ManagementAndGeneralAmt>1607</ManagementAndGeneralAmt>
      </InsuranceGrp>
      <OtherExpensesGrp>
        <Desc>ANNUAL MEETING</Desc>
        <TotalAmt>18804</TotalAmt>
        <ProgramServicesAmt>18804</ProgramServicesAmt>
      </OtherExpensesGrp>
      <OtherExpensesGrp>
        <Desc>PUBLICATION</Desc>
        <TotalAmt>11214</TotalAmt>
        <ProgramServicesAmt>11214</ProgramServicesAmt>
      </OtherExpensesGrp>
      <OtherExpensesGrp>
        <Desc>SUPPORT GROUPS</Desc>
        <TotalAmt>5812</TotalAmt>
        <ProgramServicesAmt>5812</ProgramServicesAmt>
      </OtherExpensesGrp>
      <OtherExpensesGrp>
        <Desc>RESEARCH COMMITTEE</Desc>
        <TotalAmt>4685</TotalAmt>
        <ProgramServicesAmt>4685</ProgramServicesAmt>
      </OtherExpensesGrp>
      <AllOtherExpensesGrp>
        <TotalAmt>2067</TotalAmt>
        <ManagementAndGeneralAmt>1885</ManagementAndGeneralAmt>
        <FundraisingAmt>182</FundraisingAmt>
      </AllOtherExpensesGrp>
      <TotalFunctionalExpensesGrp>
        <TotalAmt>117596</TotalAmt>
        <ProgramServicesAmt>102685</ProgramServicesAmt>
        <ManagementAndGeneralAmt>14729</ManagementAndGeneralAmt>
        <FundraisingAmt>182</FundraisingAmt>
      </TotalFunctionalExpensesGrp>
      <SavingsAndTempCashInvstGrp>
        <BOYAmt>222861</BOYAmt>
        <EOYAmt>236058</EOYAmt>
      </SavingsAndTempCashInvstGrp>
      <AccountsReceivableGrp>
        <BOYAmt>5944</BOYAmt>
        <EOYAmt>2899</EOYAmt>
      </AccountsReceivableGrp>
      <InventoriesForSaleOrUseGrp>
        <BOYAmt>1668</BOYAmt>
        <EOYAmt>1150</EOYAmt>
      </InventoriesForSaleOrUseGrp>
      <PrepaidExpensesDefrdChargesGrp>
        <BOYAmt>3663</BOYAmt>
        <EOYAmt>4701</EOYAmt>
      </PrepaidExpensesDefrdChargesGrp>
      <TotalAssetsGrp>
        <BOYAmt>234136</BOYAmt>
        <EOYAmt>244808</EOYAmt>
      </TotalAssetsGrp>
      <AccountsPayableAccrExpnssGrp>
        <BOYAmt>4425</BOYAmt>
        <EOYAmt>320</EOYAmt>
      </AccountsPayableAccrExpnssGrp>
      <GrantsPayableGrp>
        <BOYAmt>31500</BOYAmt>
        <EOYAmt>1500</EOYAmt>
      </GrantsPayableGrp>
      <OtherLiabilitiesGrp>
        <BOYAmt>1140</BOYAmt>
        <EOYAmt>2856</EOYAmt>
      </OtherLiabilitiesGrp>
      <TotalLiabilitiesGrp>
        <BOYAmt>37065</BOYAmt>
        <EOYAmt>4676</EOYAmt>
      </TotalLiabilitiesGrp>
      <OrgDoesNotFollowSFAS117Ind>X</OrgDoesNotFollowSFAS117Ind>
      <RtnEarnEndowmentIncmOthFndsGrp>
        <BOYAmt>197071</BOYAmt>
        <EOYAmt>240132</EOYAmt>
      </RtnEarnEndowmentIncmOthFndsGrp>
      <TotalNetAssetsFundBalanceGrp>
        <BOYAmt>197071</BOYAmt>
        <EOYAmt>240132</EOYAmt>
      </TotalNetAssetsFundBalanceGrp>
      <TotLiabNetAssetsFundBalanceGrp>
        <BOYAmt>234136</BOYAmt>
        <EOYAmt>244808</EOYAmt>
      </TotLiabNetAssetsFundBalanceGrp>
      <ReconcilationRevenueExpnssAmt>43061</ReconcilationRevenueExpnssAmt>
      <MethodOfAccountingAccrualInd>X</MethodOfAccountingAccrualInd>
      <AccountantCompileOrReviewInd>false</AccountantCompileOrReviewInd>
      <FSAuditedInd>true</FSAuditedInd>
      <FSAuditedBasisGrp>
        <SeparateBasisFinclStmtInd>X</SeparateBasisFinclStmtInd>
      </FSAuditedBasisGrp>
      <AuditCommitteeInd>true</AuditCommitteeInd>
      <FederalGrantAuditRequiredInd>false</FederalGrantAuditRequiredInd>
    </IRS990>
    <IRS990ScheduleA documentId="RetDoc7">
      <PubliclySupportedOrg509a2Ind>X</PubliclySupportedOrg509a2Ind>
      <GiftsGrantsContrisRcvd509Grp>
        <CurrentTaxYearMinus4YearsAmt>216928</CurrentTaxYearMinus4YearsAmt>
        <CurrentTaxYearMinus3YearsAmt>191858</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>242547</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>269276</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>125267</CurrentTaxYearAmt>
        <TotalAmt>1045876</TotalAmt>
      </GiftsGrantsContrisRcvd509Grp>
      <GrossReceiptsAdmissionsGrp>
        <CurrentTaxYearMinus4YearsAmt>867</CurrentTaxYearMinus4YearsAmt>
        <CurrentTaxYearMinus3YearsAmt>259</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>658</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>228</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>256</CurrentTaxYearAmt>
        <TotalAmt>2268</TotalAmt>
      </GrossReceiptsAdmissionsGrp>
      <Total509Grp>
        <CurrentTaxYearMinus4YearsAmt>217795</CurrentTaxYearMinus4YearsAmt>
        <CurrentTaxYearMinus3YearsAmt>192117</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>243205</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>269504</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>125523</CurrentTaxYearAmt>
        <TotalAmt>1048144</TotalAmt>
      </Total509Grp>
      <PublicSupportTotal509Amt>1048144</PublicSupportTotal509Amt>
      <GrossInvestmentIncome509Grp>
        <CurrentTaxYearMinus4YearsAmt>867</CurrentTaxYearMinus4YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>658</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>229</CurrentTaxYearMinus1YearAmt>
        <TotalAmt>1754</TotalAmt>
      </GrossInvestmentIncome509Grp>
      <InvestmentIncomeAndUBTIGrp>
        <CurrentTaxYearMinus4YearsAmt>867</CurrentTaxYearMinus4YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>658</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>229</CurrentTaxYearMinus1YearAmt>
        <TotalAmt>1754</TotalAmt>
      </InvestmentIncomeAndUBTIGrp>
      <NetIncomeFromOtherUBIGrp>
        <CurrentTaxYearMinus1YearAmt>376</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>34134</CurrentTaxYearAmt>
        <TotalAmt>34510</TotalAmt>
      </NetIncomeFromOtherUBIGrp>
      <TotalSupportCalendarYearGrp>
        <CurrentTaxYearMinus4YearsAmt>218662</CurrentTaxYearMinus4YearsAmt>
        <CurrentTaxYearMinus3YearsAmt>192117</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>243863</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>270109</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>159657</CurrentTaxYearAmt>
        <TotalAmt>1084408</TotalAmt>
      </TotalSupportCalendarYearGrp>
      <PublicSupportCY509Pct>0.96660</PublicSupportCY509Pct>
      <PublicSupportPY509Pct>0.98110</PublicSupportPY509Pct>
      <InvestmentIncomeCYPct>0.00000</InvestmentIncomeCYPct>
      <InvestmentIncomePYPct>0.01000</InvestmentIncomePYPct>
      <ThirtyThrPctSuprtTestsCY509Ind>X</ThirtyThrPctSuprtTestsCY509Ind>
      <Form990ScheduleAPartVIGrp>
        <FormAndLineReferenceDesc>PART III, LINE 12</FormAndLineReferenceDesc>
        <ExplanationTxt>OTHER INCOME 0</ExplanationTxt>
      </Form990ScheduleAPartVIGrp>
    </IRS990ScheduleA>
    <IRS990ScheduleB documentId="RetDoc1">
      <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>
    <IRS990ScheduleD documentId="RetDoc3">
      <OtherLiabilitiesOrgGrp>
        <Desc>OTHER</Desc>
        <Amt>2856</Amt>
      </OtherLiabilitiesOrgGrp>
      <TotalLiabilityAmt>2856</TotalLiabilityAmt>
      <TotalRevEtcAuditedFinclStmtAmt>160657</TotalRevEtcAuditedFinclStmtAmt>
      <RevenueSubtotalAmt>160657</RevenueSubtotalAmt>
      <TotalRevenuePerForm990Amt>160657</TotalRevenuePerForm990Amt>
      <TotExpnsEtcAuditedFinclStmtAmt>117596</TotExpnsEtcAuditedFinclStmtAmt>
      <ExpensesSubtotalAmt>117596</ExpensesSubtotalAmt>
      <TotalExpensesPerForm990Amt>117596</TotalExpensesPerForm990Amt>
    </IRS990ScheduleD>
    <IRS990ScheduleG documentId="RetDoc4">
      <FundraisingEventInformationGrp>
        <Event1Nm>FUNDRAISING</Event1Nm>
        <GrossReceiptsEvent1Amt>32624</GrossReceiptsEvent1Amt>
        <CharitableContriEvent1Amt>32624</CharitableContriEvent1Amt>
        <GrossReceiptsTotalAmt>32624</GrossReceiptsTotalAmt>
        <CharitableContributionsTotAmt>32624</CharitableContributionsTotAmt>
      </FundraisingEventInformationGrp>
    </IRS990ScheduleG>
    <IRS990ScheduleI documentId="RetDoc5">
      <GrantRecordsMaintainedInd>true</GrantRecordsMaintainedInd>
      <RecipientTable>
        <RecipientBusinessName>
          <BusinessNameLine1Txt>REGENTS OF THE UNIVERSITY OF MN</BusinessNameLine1Txt>
        </RecipientBusinessName>
        <USAddress>
          <AddressLine1Txt>PO BOX 1450</AddressLine1Txt>
          <CityNm>MINNEAPOLIS</CityNm>
          <StateAbbreviationCd>MN</StateAbbreviationCd>
          <ZIPCd>55485</ZIPCd>
        </USAddress>
        <RecipientEIN>416007513</RecipientEIN>
        <CashGrantAmt>10000</CashGrantAmt>
        <PurposeOfGrantTxt>RESEARCH</PurposeOfGrantTxt>
      </RecipientTable>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>SCHEDULE I, PAGE 1, PART I, LINE 2</FormAndLineReferenceDesc>
        <ExplanationTxt>THE SOCIETY REVIEWS, AND IF APPROPRIATE, APPROVES REQUESTS FOR GRANTS AND OTHER ASSISTANCE FOR SUPPORT AND RESEARCH OF MASTOCYTOSIS/MAST CELL ACTIVATION DISORDERS.</ExplanationTxt>
      </SupplementalInformationDetail>
    </IRS990ScheduleI>
    <IRS990ScheduleO documentId="RetDoc6">
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990 - ORGANIZATION'S MISSION</FormAndLineReferenceDesc>
        <ExplanationTxt>THE MASTOCYTOSIS SOCITY IS A NONPROFIT ORGANIZATION DEDICATED TO SUPPORTING PATIENTS AFFECTED BY MASTOCYTOSIS/MAST CELL ACTIVATION DISORDERS AS WELL AS THEIR FAMILIES, CAREGIVERS AND PHYSICIANS THROUGH RESEARCH, EDUCATION AND ADVOCACY.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PAGE 2, PART III, LINE 4D</FormAndLineReferenceDesc>
        <ExplanationTxt>PUBLICATIONS AND OTHER SUPPORT GROUP SUBSIDIES FOR PARTICIPANTS IN ANNUAL MEETINGS</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PAGE 6, PART VI, LINE 7A</FormAndLineReferenceDesc>
        <ExplanationTxt>MEMBERS HAVE THE POWER TO ELECT OR APPOINT ONE OR MORE MEMBERS OF THE GOVERNING BODY</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PAGE 6, PART VI, LINE 7B</FormAndLineReferenceDesc>
        <ExplanationTxt>GOVERNANCE DECISIONS OF THE ORGANIZATION ARE RESERVED TO MEMBERS</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PAGE 6, PART VI, LINE 11B</FormAndLineReferenceDesc>
        <ExplanationTxt>FORM 990 REVIEWED MY MANAGEMENT TEAM</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PAGE 6, PART VI, LINE 12C</FormAndLineReferenceDesc>
        <ExplanationTxt>MANAGEMENT REVIEWS POLICIES AND ENSURES COMPLIANCE BY ALL GOVERNING MEMBERS</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PAGE 6, PART VI, LINE 15A</FormAndLineReferenceDesc>
        <ExplanationTxt>NO COMPENSATION FOR CEO OR EXECUTIVE MEMBERS</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PAGE 6, PART VI, LINE 15B</FormAndLineReferenceDesc>
        <ExplanationTxt>NO COMPENSATION FOR OTHER OFFICERS</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>FORM 990, PAGE 6, PART VI, LINE 19</FormAndLineReferenceDesc>
        <ExplanationTxt>DOCUMENTS ARE AVAILABLE UPON REQUEST</ExplanationTxt>
      </SupplementalInformationDetail>
    </IRS990ScheduleO>
  </ReturnData>
</Return>