﻿<?xml version="1.0" encoding="utf-8"?>
<Return xmlns="http://www.irs.gov/efile" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" returnVersion="2024v5.2" xsi:schemaLocation="http://www.irs.gov/efile">
  <ReturnHeader binaryAttachmentCnt="0">
    <ReturnTs>2026-08-12T10:54:16-07:00</ReturnTs>
    <TaxPeriodEndDt>2025-09-30</TaxPeriodEndDt>
    <PreparerFirmGrp>
      <PreparerFirmEIN>043432473</PreparerFirmEIN>
      <PreparerFirmName>
        <BusinessNameLine1Txt>Turner &amp; Costa PC</BusinessNameLine1Txt>
      </PreparerFirmName>
      <PreparerUSAddress>
        <AddressLine1Txt>190 Littleton Rd</AddressLine1Txt>
        <CityNm>Westford</CityNm>
        <StateAbbreviationCd>MA</StateAbbreviationCd>
        <ZIPCd>01886</ZIPCd>
      </PreparerUSAddress>
    </PreparerFirmGrp>
    <ReturnTypeCd>990EZ</ReturnTypeCd>
    <TaxPeriodBeginDt>2024-10-01</TaxPeriodBeginDt>
    <Filer>
      <EIN>043583648</EIN>
      <BusinessName>
        <BusinessNameLine1Txt>Rett Syndrome Association of Massachusetts Inc</BusinessNameLine1Txt>
      </BusinessName>
      <BusinessNameControlTxt>RETT</BusinessNameControlTxt>
      <PhoneNum>5084809567</PhoneNum>
      <USAddress>
        <AddressLine1Txt>217 South Street</AddressLine1Txt>
        <CityNm>Waltham</CityNm>
        <StateAbbreviationCd>MA</StateAbbreviationCd>
        <ZIPCd>02453</ZIPCd>
      </USAddress>
    </Filer>
    <BusinessOfficerGrp>
      <PersonNm>Coriann Stinson</PersonNm>
      <PersonTitleTxt>Treasurer</PersonTitleTxt>
      <PhoneNum>5084809567</PhoneNum>
      <SignatureDt>2026-01-14</SignatureDt>
    </BusinessOfficerGrp>
    <IRSResponsiblePrtyInfoCurrInd>true</IRSResponsiblePrtyInfoCurrInd>
    <PreparerPersonGrp>
      <PreparerPersonNm>Robert M Turner</PreparerPersonNm>
      <PTIN>P00497567</PTIN>
      <PhoneNum>9786923291</PhoneNum>
      <PreparationDt>2026-08-12</PreparationDt>
    </PreparerPersonGrp>
    <TaxYr>2024</TaxYr>
    <BuildTS>2025-03-06 01:10:19Z</BuildTS>
  </ReturnHeader>
  <ReturnData documentCnt="5">
    <IRS990EZ documentId="IRS990EZ-01" referenceDocumentId="IRS990ScheduleO-01">
      <MethodOfAccountingCashInd>X</MethodOfAccountingCashInd>
      <WebsiteAddressTxt>N/A</WebsiteAddressTxt>
      <Organization501c3Ind referenceDocumentId="IRS990ScheduleA-01" referenceDocumentName="IRS990ScheduleA">X</Organization501c3Ind>
      <TypeOfOrganizationCorpInd>X</TypeOfOrganizationCorpInd>
      <GrossReceiptsAmt>79547</GrossReceiptsAmt>
      <InfoInScheduleOPartIInd>X</InfoInScheduleOPartIInd>
      <ContributionsGiftsGrantsEtcAmt>12615</ContributionsGiftsGrantsEtcAmt>
      <ProgramServiceRevenueAmt>0</ProgramServiceRevenueAmt>
      <MembershipDuesAmt>0</MembershipDuesAmt>
      <InvestmentIncomeAmt>0</InvestmentIncomeAmt>
      <CostOrOtherBasisExpenseSaleAmt>0</CostOrOtherBasisExpenseSaleAmt>
      <GainOrLossFromSaleOfAssetsAmt>0</GainOrLossFromSaleOfAssetsAmt>
      <FundraisingGrossIncomeAmt referenceDocumentId="IRS990ScheduleG-01" referenceDocumentName="IRS990ScheduleG">66932</FundraisingGrossIncomeAmt>
      <SpecialEventsDirectExpensesAmt>26690</SpecialEventsDirectExpensesAmt>
      <SpecialEventsNetIncomeLossAmt>40242</SpecialEventsNetIncomeLossAmt>
      <CostOfGoodsSoldAmt>0</CostOfGoodsSoldAmt>
      <GrossProfitLossSlsOfInvntryAmt>0</GrossProfitLossSlsOfInvntryAmt>
      <TotalRevenueAmt>52857</TotalRevenueAmt>
      <GrantsAndSimilarAmountsPaidAmt>50750</GrantsAndSimilarAmountsPaidAmt>
      <FeesAndOtherPymtToIndCntrctAmt>85</FeesAndOtherPymtToIndCntrctAmt>
      <OtherExpensesTotalAmt>8677</OtherExpensesTotalAmt>
      <TotalExpensesAmt>59512</TotalExpensesAmt>
      <ExcessOrDeficitForYearAmt>-6655</ExcessOrDeficitForYearAmt>
      <NetAssetsOrFundBalancesBOYAmt>146501</NetAssetsOrFundBalancesBOYAmt>
      <NetAssetsOrFundBalancesEOYAmt>139846</NetAssetsOrFundBalancesEOYAmt>
      <InfoInScheduleOPartIIInd>X</InfoInScheduleOPartIIInd>
      <CashSavingsAndInvestmentsGrp>
        <BOYAmt>146501</BOYAmt>
        <EOYAmt>124846</EOYAmt>
      </CashSavingsAndInvestmentsGrp>
      <OtherAssetsTotalDetail>
        <BOYAmt>0</BOYAmt>
        <EOYAmt>15000</EOYAmt>
      </OtherAssetsTotalDetail>
      <Form990TotalAssetsGrp>
        <BOYAmt>146501</BOYAmt>
        <EOYAmt>139846</EOYAmt>
      </Form990TotalAssetsGrp>
      <NetAssetsOrFundBalancesGrp>
        <BOYAmt>146501</BOYAmt>
        <EOYAmt>139846</EOYAmt>
      </NetAssetsOrFundBalancesGrp>
      <PrimaryExemptPurposeTxt>To provide support and information to families; To raise funds to accelerate biomedical research; To raise public awareness among medical and educational communities</PrimaryExemptPurposeTxt>
      <ProgramSrvcAccomplishmentGrp>
        <DescriptionProgramSrvcAccomTxt>Fund research and host events to raise awareness.</DescriptionProgramSrvcAccomTxt>
        <GrantsAndAllocationsAmt>0</GrantsAndAllocationsAmt>
        <ProgramServiceExpensesAmt>59512</ProgramServiceExpensesAmt>
      </ProgramSrvcAccomplishmentGrp>
      <TotalProgramServiceExpensesAmt>59512</TotalProgramServiceExpensesAmt>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>Larry Fallon</PersonNm>
        <TitleTxt>President</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>5.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
        <EmployeeBenefitProgramAmt>0</EmployeeBenefitProgramAmt>
        <ExpenseAccountOtherAllwncAmt>0</ExpenseAccountOtherAllwncAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>Irene Gladstone</PersonNm>
        <TitleTxt>Vice President</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>5.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
        <EmployeeBenefitProgramAmt>0</EmployeeBenefitProgramAmt>
        <ExpenseAccountOtherAllwncAmt>0</ExpenseAccountOtherAllwncAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>Coriann Stinson</PersonNm>
        <TitleTxt>Treasurer</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>5.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
        <EmployeeBenefitProgramAmt>0</EmployeeBenefitProgramAmt>
        <ExpenseAccountOtherAllwncAmt>0</ExpenseAccountOtherAllwncAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>Jill Twigg</PersonNm>
        <TitleTxt>Clerk</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>5.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
        <EmployeeBenefitProgramAmt>0</EmployeeBenefitProgramAmt>
        <ExpenseAccountOtherAllwncAmt>0</ExpenseAccountOtherAllwncAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>Tonya Chever</PersonNm>
        <TitleTxt>Director</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>1.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
        <EmployeeBenefitProgramAmt>0</EmployeeBenefitProgramAmt>
        <ExpenseAccountOtherAllwncAmt>0</ExpenseAccountOtherAllwncAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>Bill Johnson</PersonNm>
        <TitleTxt>Director</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>1.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
        <EmployeeBenefitProgramAmt>0</EmployeeBenefitProgramAmt>
        <ExpenseAccountOtherAllwncAmt>0</ExpenseAccountOtherAllwncAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>Paul Lopes</PersonNm>
        <TitleTxt>Director</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>1.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
        <EmployeeBenefitProgramAmt>0</EmployeeBenefitProgramAmt>
        <ExpenseAccountOtherAllwncAmt>0</ExpenseAccountOtherAllwncAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>Jennifer Sanderson</PersonNm>
        <TitleTxt>Director</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>1.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
        <EmployeeBenefitProgramAmt>0</EmployeeBenefitProgramAmt>
        <ExpenseAccountOtherAllwncAmt>0</ExpenseAccountOtherAllwncAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>Julia Schneiders</PersonNm>
        <TitleTxt>Director</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>1.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
        <EmployeeBenefitProgramAmt>0</EmployeeBenefitProgramAmt>
        <ExpenseAccountOtherAllwncAmt>0</ExpenseAccountOtherAllwncAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>Kathy Schoener</PersonNm>
        <TitleTxt>Director</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>1.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
        <EmployeeBenefitProgramAmt>0</EmployeeBenefitProgramAmt>
        <ExpenseAccountOtherAllwncAmt>0</ExpenseAccountOtherAllwncAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>Nili Smallcomb</PersonNm>
        <TitleTxt>Director</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>1.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
        <EmployeeBenefitProgramAmt>0</EmployeeBenefitProgramAmt>
        <ExpenseAccountOtherAllwncAmt>0</ExpenseAccountOtherAllwncAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm>Maggie Wurm</PersonNm>
        <TitleTxt>Director</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>1.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
        <EmployeeBenefitProgramAmt>0</EmployeeBenefitProgramAmt>
        <ExpenseAccountOtherAllwncAmt>0</ExpenseAccountOtherAllwncAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <InfoInScheduleOPartVInd>X</InfoInScheduleOPartVInd>
      <ActivitiesNotPreviouslyRptInd>false</ActivitiesNotPreviouslyRptInd>
      <ChgMadeToOrgnzngDocNotRptInd>false</ChgMadeToOrgnzngDocNotRptInd>
      <OrganizationHadUBIInd>false</OrganizationHadUBIInd>
      <SubjectToProxyTaxInd>false</SubjectToProxyTaxInd>
      <OrganizationDissolvedEtcInd>false</OrganizationDissolvedEtcInd>
      <Form1120PolFiledInd>false</Form1120PolFiledInd>
      <MadeLoansToFromOfficersInd>false</MadeLoansToFromOfficersInd>
      <InitiationFeesAndCapContriAmt>0</InitiationFeesAndCapContriAmt>
      <GrossReceiptsForPublicUseAmt>0</GrossReceiptsForPublicUseAmt>
      <EngagedInExcessBenefitTransInd>false</EngagedInExcessBenefitTransInd>
      <ProhibitedTaxShelterTransInd>false</ProhibitedTaxShelterTransInd>
      <StatesWhereCopyOfReturnIsFldCd>MA</StatesWhereCopyOfReturnIsFldCd>
      <BooksInCareOfDetail>
        <PersonNm>Kathleen Schoener</PersonNm>
        <USAddress>
          <AddressLine1Txt>28 Constitution Dr</AddressLine1Txt>
          <CityNm>Dedham</CityNm>
          <StateAbbreviationCd>MA</StateAbbreviationCd>
          <ZIPCd>02026</ZIPCd>
        </USAddress>
        <PhoneNum>5084809667</PhoneNum>
      </BooksInCareOfDetail>
      <ForeignFinancialAccountInd>false</ForeignFinancialAccountInd>
      <ForeignOfficeInd>false</ForeignOfficeInd>
      <DonorAdvisedFndsInd>false</DonorAdvisedFndsInd>
      <OperateHospitalInd>false</OperateHospitalInd>
      <TanningServicesProvidedInd>false</TanningServicesProvidedInd>
      <RelatedOrganizationCtrlEntInd>false</RelatedOrganizationCtrlEntInd>
      <TransactionWithControlEntInd>false</TransactionWithControlEntInd>
      <PoliticalCampaignActyInd>false</PoliticalCampaignActyInd>
      <LobbyingActivitiesInd>false</LobbyingActivitiesInd>
      <SchoolOperatingInd>false</SchoolOperatingInd>
      <TrnsfrExmptNonChrtblRltdOrgInd>false</TrnsfrExmptNonChrtblRltdOrgInd>
      <PartVIOfCompOfHghstPdEmplTxt>NONE</PartVIOfCompOfHghstPdEmplTxt>
      <PartVIHghstPdCntrctProfSrvcTxt>NONE</PartVIHghstPdCntrctProfSrvcTxt>
      <FiledScheduleAInd>true</FiledScheduleAInd>
    </IRS990EZ>
    <IRS990ScheduleA documentId="IRS990ScheduleA-01" softwareId="24020153">
      <PubliclySupportedOrg509a2Ind>X</PubliclySupportedOrg509a2Ind>
      <OtherSupportSumAmt>0</OtherSupportSumAmt>
      <PublicSupportCY170Pct>0</PublicSupportCY170Pct>
      <GiftsGrantsContrisRcvd509Grp>
        <CurrentTaxYearMinus4YearsAmt>38747</CurrentTaxYearMinus4YearsAmt>
        <CurrentTaxYearMinus3YearsAmt>78871</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>76688</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>36306</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>12615</CurrentTaxYearAmt>
        <TotalAmt>243227</TotalAmt>
      </GiftsGrantsContrisRcvd509Grp>
      <GrossReceiptsAdmissionsGrp>
        <CurrentTaxYearAmt>66932</CurrentTaxYearAmt>
        <TotalAmt>66932</TotalAmt>
      </GrossReceiptsAdmissionsGrp>
      <GrossReceiptsNonUnrltBusGrp>
        <TotalAmt>0</TotalAmt>
      </GrossReceiptsNonUnrltBusGrp>
      <TaxRevLeviedOrgnztnlBnft509Grp>
        <TotalAmt>0</TotalAmt>
      </TaxRevLeviedOrgnztnlBnft509Grp>
      <Total509Grp>
        <CurrentTaxYearMinus4YearsAmt>38747</CurrentTaxYearMinus4YearsAmt>
        <CurrentTaxYearMinus3YearsAmt>78871</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>76688</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>36306</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>79547</CurrentTaxYearAmt>
        <TotalAmt>310159</TotalAmt>
      </Total509Grp>
      <AmountsRcvdDsqlfyPersonGrp>
        <TotalAmt>0</TotalAmt>
      </AmountsRcvdDsqlfyPersonGrp>
      <SubstantialContributorsAmtGrp>
        <TotalAmt>0</TotalAmt>
      </SubstantialContributorsAmtGrp>
      <SubstAndDsqlfyPrsnsTotGrp>
        <TotalAmt>0</TotalAmt>
      </SubstAndDsqlfyPrsnsTotGrp>
      <PublicSupportTotal509Amt>310159</PublicSupportTotal509Amt>
      <TotalSupportCalendarYearGrp>
        <TotalAmt>310159</TotalAmt>
      </TotalSupportCalendarYearGrp>
      <PublicSupportCY509Pct>1.00000</PublicSupportCY509Pct>
      <InvestmentIncomeCYPct>0.00000</InvestmentIncomeCYPct>
      <ThirtyThrPctSuprtTestsCY509Ind>X</ThirtyThrPctSuprtTestsCY509Ind>
    </IRS990ScheduleA>
    <IRS990ScheduleB documentId="IRS990ScheduleB-01">
      <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>
    <IRS990ScheduleG documentId="IRS990ScheduleG-01">
      <FundraisingEventInformationGrp>
        <Event1Nm>GivenGain</Event1Nm>
        <GrossReceiptsEvent1Amt>30062</GrossReceiptsEvent1Amt>
        <GrossRevenueEvent1Amt>30062</GrossRevenueEvent1Amt>
        <Event2Nm>Golf Tournament</Event2Nm>
        <GrossReceiptsEvent2Amt>6345</GrossReceiptsEvent2Amt>
        <CharitableContriEvent2Amt>3500</CharitableContriEvent2Amt>
        <GrossRevenueEvent2Amt>2845</GrossRevenueEvent2Amt>
        <OtherDirectExpensesEvent2Amt>15022</OtherDirectExpensesEvent2Amt>
        <GrossReceiptsTotalAmt>36407</GrossReceiptsTotalAmt>
        <CharitableContributionsTotAmt>3500</CharitableContributionsTotAmt>
        <GrossRevenueTotalEventsAmt>32907</GrossRevenueTotalEventsAmt>
        <OthDirectExpnssTotalEventsAmt>15022</OthDirectExpnssTotalEventsAmt>
        <DirectExpenseSummaryEventsAmt>15022</DirectExpenseSummaryEventsAmt>
        <NetIncomeSummaryAmt>17885</NetIncomeSummaryAmt>
      </FundraisingEventInformationGrp>
    </IRS990ScheduleG>
    <IRS990ScheduleO documentId="IRS990ScheduleO-01" softwareId="24020153">
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Form 990EZ, Part I, Line 10</FormAndLineReferenceDesc>
        <ExplanationTxt>Contribution; Funding for research; Rett Syndrome Research Trust: 67 Under Cliff Road, Trumbull, CT, 06611; Related Organization, 50000.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Form 990EZ, Part I, Line 10</FormAndLineReferenceDesc>
        <ExplanationTxt>Donation; Grant; Olivia Hilario: , , , ; , 500.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Form 990EZ, Part I, Line 10</FormAndLineReferenceDesc>
        <ExplanationTxt>Donation; Event donation; Hearts &amp; Noses: PO Box 920570, Needham, MA, 02492; Related Organization, 250.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Form 990EZ, Part I, Line 16</FormAndLineReferenceDesc>
        <ExplanationTxt>Scholarships 6000.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Form 990EZ, Part I, Line 16</FormAndLineReferenceDesc>
        <ExplanationTxt>Office Expense 1413.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Form 990EZ, Part I, Line 16</FormAndLineReferenceDesc>
        <ExplanationTxt>Supplies 705.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Form 990EZ, Part I, Line 16</FormAndLineReferenceDesc>
        <ExplanationTxt>Gifts 559.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Form 990EZ, Part II, Line 24</FormAndLineReferenceDesc>
        <ExplanationTxt>Undeposited Funds 0. 15000.</ExplanationTxt>
      </SupplementalInformationDetail>
    </IRS990ScheduleO>
  </ReturnData>
</Return>