﻿<?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="2012v2.1">
  <ReturnHeader binaryAttachmentCount="0">
    <Timestamp>2014-03-20T08:13:46-05:00</Timestamp>
    <TaxPeriodEndDate>2013-09-30</TaxPeriodEndDate>
    <PreparerFirm>
      <EIN>061009205</EIN>
      <PreparerFirmBusinessName>
        <BusinessNameLine1>BLUM SHAPIRO &amp; COMPANY PC</BusinessNameLine1>
      </PreparerFirmBusinessName>
      <PreparerFirmUSAddress>
        <AddressLine1>1 PINE HILL DRIVE SUITE 301</AddressLine1>
        <City>QUINCY</City>
        <State>MA</State>
        <ZIPCode>021697431</ZIPCode>
      </PreparerFirmUSAddress>
    </PreparerFirm>
    <ReturnType>990EZ</ReturnType>
    <TaxPeriodBeginDate>2012-10-01</TaxPeriodBeginDate>
    <Filer>
      <EIN>043469680</EIN>
      <Name>
        <BusinessNameLine1>OBSTETRICAL SOCIETY OF BOSTON INC</BusinessNameLine1>
        <BusinessNameLine2>C/O ELIZABETH BUECHLER</BusinessNameLine2>
      </Name>
      <NameControl>OBST</NameControl>
      <Phone>7813065304</Phone>
      <USAddress>
        <AddressLine1>26 CITY HALL MALL</AddressLine1>
        <City>MEDFORD</City>
        <State>MA</State>
        <ZIPCode>02155</ZIPCode>
      </USAddress>
    </Filer>
    <Officer>
      <Name>ELIZABETH BUECHLER MD</Name>
      <Title>TREASURER</Title>
      <Phone>7813065304</Phone>
      <DateSigned>2014-02-20</DateSigned>
      <AuthorizeThirdParty>1</AuthorizeThirdParty>
    </Officer>
    <Preparer>
      <Name>TRACI L POZERSKI CPA</Name>
      <PTIN>P00415905</PTIN>
      <Phone>7819821001</Phone>
      <DatePrepared>2014-02-20</DatePrepared>
    </Preparer>
    <TaxYear>2012</TaxYear>
    <BuildTS>2015-11-30 17:44:51Z</BuildTS>
  </ReturnHeader>
  <ReturnData documentCount="4">
    <IRS990EZ documentId="RetDoc1234200001" referenceDocumentId="RetDoc1051800001 RetDoc2278000001">
      <MethodOfAccountingCash>X</MethodOfAccountingCash>
      <ScheduleBNotRequired>X</ScheduleBNotRequired>
      <WebSite>WWW.BOSTONOB.ORG</WebSite>
      <Organization501c3 referenceDocumentId="RetDoc1039100001">X</Organization501c3>
      <GrossReceipts>34262</GrossReceipts>
      <InfoInScheduleOPartI>X</InfoInScheduleOPartI>
      <MembershipDues>34259</MembershipDues>
      <InvestmentIncome>3</InvestmentIncome>
      <TotalRevenue>34262</TotalRevenue>
      <OtherExpensesTotal>42007</OtherExpensesTotal>
      <TotalExpenses>42007</TotalExpenses>
      <ExcessOrDeficitForYear>-7745</ExcessOrDeficitForYear>
      <NetAssetsOrFundBalancesBOY>42534</NetAssetsOrFundBalancesBOY>
      <OtherChangesInNetAssets>0</OtherChangesInNetAssets>
      <NetAssetsOrFundBalancesEOY>34789</NetAssetsOrFundBalancesEOY>
      <CashSavingsAndInvestments>
        <BOY>42534</BOY>
        <EOY>34789</EOY>
      </CashSavingsAndInvestments>
      <TotalAssets>
        <BOY>42534</BOY>
        <EOY>34789</EOY>
      </TotalAssets>
      <SumOfTotalLiabilities>
        <BOY>0</BOY>
        <EOY>0</EOY>
      </SumOfTotalLiabilities>
      <NetAssetsOrFundBalances>
        <BOY>42534</BOY>
        <EOY>34789</EOY>
      </NetAssetsOrFundBalances>
      <InfoInScheduleOPartIII>X</InfoInScheduleOPartIII>
      <PrimaryExemptPurpose>TO CULTIVATE AND DISSEMINATE SCIENTIFIC KNOWLEDGE IN THE AREAS OF OBSTETRICS, GYNECOLOGY, AND REPRODUCTIVE ENDOCRINOLOGY.</PrimaryExemptPurpose>
      <ProgramServiceAccomplishment>
        <DescriptionProgramServiceAccom>CONDUCTED MEETINGS OF MEDICAL PROFESSIONALS WITHIN THE FIELDS OF GYNECOLOGY AND OBSTETRICS TO FOSTER DISCUSSIONS TO ENHANCE KNOWLEDGE AND PATIENT TREATMENT.</DescriptionProgramServiceAccom>
        <GrantsAndAllocations>0</GrantsAndAllocations>
        <ProgramServiceExpenses>42007</ProgramServiceExpenses>
      </ProgramServiceAccomplishment>
      <TotalProgramServiceExpenses>42007</TotalProgramServiceExpenses>
      <OfficerDirectorTrusteeKeyEmpl>
        <PersonName>PATRICK SWEENEY MD</PersonName>
        <Title>VP THRU 6/2013; PRES. AS OF 7/2013</Title>
        <AvgHoursPerWkDevotedToPosition>2.00</AvgHoursPerWkDevotedToPosition>
        <Compensation>0</Compensation>
        <ContriToEmplBenefitPlansEtc>0</ContriToEmplBenefitPlansEtc>
        <ExpenseAccountOtherAllowances>0</ExpenseAccountOtherAllowances>
      </OfficerDirectorTrusteeKeyEmpl>
      <OfficerDirectorTrusteeKeyEmpl>
        <PersonName>AVIVA LEE-PARRITZ MD</PersonName>
        <Title>PRES. THRU 6/13;PAST PRES.A/O 7/13</Title>
        <AvgHoursPerWkDevotedToPosition>2.00</AvgHoursPerWkDevotedToPosition>
        <Compensation>0</Compensation>
        <ContriToEmplBenefitPlansEtc>0</ContriToEmplBenefitPlansEtc>
        <ExpenseAccountOtherAllowances>0</ExpenseAccountOtherAllowances>
      </OfficerDirectorTrusteeKeyEmpl>
      <OfficerDirectorTrusteeKeyEmpl>
        <PersonName>ELIZABETH BUECHLER MD</PersonName>
        <Title>TREASURER</Title>
        <AvgHoursPerWkDevotedToPosition>3.00</AvgHoursPerWkDevotedToPosition>
        <Compensation>0</Compensation>
        <ContriToEmplBenefitPlansEtc>0</ContriToEmplBenefitPlansEtc>
        <ExpenseAccountOtherAllowances>0</ExpenseAccountOtherAllowances>
      </OfficerDirectorTrusteeKeyEmpl>
      <OfficerDirectorTrusteeKeyEmpl>
        <PersonName>BETH GOLDBAUM MD</PersonName>
        <Title>SECRETARY</Title>
        <AvgHoursPerWkDevotedToPosition>1.00</AvgHoursPerWkDevotedToPosition>
        <Compensation>0</Compensation>
        <ContriToEmplBenefitPlansEtc>0</ContriToEmplBenefitPlansEtc>
        <ExpenseAccountOtherAllowances>500</ExpenseAccountOtherAllowances>
      </OfficerDirectorTrusteeKeyEmpl>
      <OfficerDirectorTrusteeKeyEmpl>
        <PersonName>RONALD IVERSON MD</PersonName>
        <Title>2ND VP THRU 6/2013; 1ST VP - 7/2013</Title>
        <AvgHoursPerWkDevotedToPosition>1.00</AvgHoursPerWkDevotedToPosition>
        <Compensation>0</Compensation>
        <ContriToEmplBenefitPlansEtc>0</ContriToEmplBenefitPlansEtc>
        <ExpenseAccountOtherAllowances>0</ExpenseAccountOtherAllowances>
      </OfficerDirectorTrusteeKeyEmpl>
      <OfficerDirectorTrusteeKeyEmpl>
        <PersonName>JULIA JOHNSONMD</PersonName>
        <Title>SECOND VICE PRESIDENT AS OF 07/2013</Title>
        <AvgHoursPerWkDevotedToPosition>1.00</AvgHoursPerWkDevotedToPosition>
        <Compensation>0</Compensation>
        <ContriToEmplBenefitPlansEtc>0</ContriToEmplBenefitPlansEtc>
        <ExpenseAccountOtherAllowances>0</ExpenseAccountOtherAllowances>
      </OfficerDirectorTrusteeKeyEmpl>
      <OfficerDirectorTrusteeKeyEmpl>
        <PersonName>JEFFERY ECKER MD</PersonName>
        <Title>PAST PRESIDENT</Title>
        <AvgHoursPerWkDevotedToPosition>1.00</AvgHoursPerWkDevotedToPosition>
        <Compensation>0</Compensation>
        <ContriToEmplBenefitPlansEtc>0</ContriToEmplBenefitPlansEtc>
        <ExpenseAccountOtherAllowances>0</ExpenseAccountOtherAllowances>
      </OfficerDirectorTrusteeKeyEmpl>
      <OfficerDirectorTrusteeKeyEmpl>
        <PersonName>SUSAN HAAS MD</PersonName>
        <Title>PAST PRESIDENT THRU 06/2013</Title>
        <AvgHoursPerWkDevotedToPosition>1.00</AvgHoursPerWkDevotedToPosition>
        <Compensation>0</Compensation>
        <ContriToEmplBenefitPlansEtc>0</ContriToEmplBenefitPlansEtc>
        <ExpenseAccountOtherAllowances>0</ExpenseAccountOtherAllowances>
      </OfficerDirectorTrusteeKeyEmpl>
      <OfficerDirectorTrusteeKeyEmpl>
        <PersonName>JOEL HELLER MD</PersonName>
        <Title>MEMBER AT LARGE</Title>
        <AvgHoursPerWkDevotedToPosition>1.00</AvgHoursPerWkDevotedToPosition>
        <Compensation>0</Compensation>
        <ContriToEmplBenefitPlansEtc>0</ContriToEmplBenefitPlansEtc>
        <ExpenseAccountOtherAllowances>0</ExpenseAccountOtherAllowances>
      </OfficerDirectorTrusteeKeyEmpl>
      <OfficerDirectorTrusteeKeyEmpl>
        <PersonName>SAMUEL PANG MD</PersonName>
        <Title>MEMBER AT LARGE AS OF 07/2013</Title>
        <AvgHoursPerWkDevotedToPosition>1.00</AvgHoursPerWkDevotedToPosition>
        <Compensation>0</Compensation>
        <ContriToEmplBenefitPlansEtc>0</ContriToEmplBenefitPlansEtc>
        <ExpenseAccountOtherAllowances>0</ExpenseAccountOtherAllowances>
      </OfficerDirectorTrusteeKeyEmpl>
      <OfficerDirectorTrusteeKeyEmpl>
        <PersonName>NAJMOSAMA NIKRUI MD</PersonName>
        <Title>MEMBER AT LARGE THRU 06/2013</Title>
        <AvgHoursPerWkDevotedToPosition>1.00</AvgHoursPerWkDevotedToPosition>
        <Compensation>0</Compensation>
        <ContriToEmplBenefitPlansEtc>0</ContriToEmplBenefitPlansEtc>
        <ExpenseAccountOtherAllowances>0</ExpenseAccountOtherAllowances>
      </OfficerDirectorTrusteeKeyEmpl>
      <InfoInScheduleOPartV>X</InfoInScheduleOPartV>
      <ActivitiesNotPreviouslyRpt>0</ActivitiesNotPreviouslyRpt>
      <MadeChangesToOrgnzngEtcDoc>0</MadeChangesToOrgnzngEtcDoc>
      <OrganizationHadUBI>0</OrganizationHadUBI>
      <SubjectToProxyTax>0</SubjectToProxyTax>
      <OrganizationDissolvedEtc>0</OrganizationDissolvedEtc>
      <DirectIndirectPoliticalExpend>0</DirectIndirectPoliticalExpend>
      <MadeLoansToFromOfficers>0</MadeLoansToFromOfficers>
      <TaxImposedUnderIRC4911>0</TaxImposedUnderIRC4911>
      <TaxImposedUnderIRC4912>0</TaxImposedUnderIRC4912>
      <TaxImposedUnderIRC4955>0</TaxImposedUnderIRC4955>
      <EngagedInExcessBenefitTrans>0</EngagedInExcessBenefitTrans>
      <AmountOfTaxImposedOnOrgMgr>0</AmountOfTaxImposedOnOrgMgr>
      <AmountOfTaxReimbursedByOrg>0</AmountOfTaxReimbursedByOrg>
      <ProhibitedTaxShelterTrans>0</ProhibitedTaxShelterTrans>
      <StatesWhereCopyOfReturnIsFiled>MA</StatesWhereCopyOfReturnIsFiled>
      <TheBooksAreInCareOf>
        <NamePerson>ELIZABETH BUECHLER MD</NamePerson>
        <AddressUS>
          <AddressLine1>26 CITY HALL MALL</AddressLine1>
          <City>MEDFORD</City>
          <State>MA</State>
          <ZIPCode>02155</ZIPCode>
        </AddressUS>
        <TelephoneNumber>7813065304</TelephoneNumber>
      </TheBooksAreInCareOf>
      <ForeignFinancialAccount>0</ForeignFinancialAccount>
      <ForeignOffice>0</ForeignOffice>
      <MaintainAnyDonorAdvisedFunds>0</MaintainAnyDonorAdvisedFunds>
      <DoesOrgHaveHospital>0</DoesOrgHaveHospital>
      <TanningServicesProvided>0</TanningServicesProvided>
      <RelatedOrgControlledEntity>0</RelatedOrgControlledEntity>
      <TransactionWithControlEntity>0</TransactionWithControlEntity>
      <EngagePoliticalCmpgnActivities>0</EngagePoliticalCmpgnActivities>
      <EngageInLobbyingActivities>0</EngageInLobbyingActivities>
      <OperatingSchool>0</OperatingSchool>
      <TrnsfrsExemptNonCharRelatedOrg>0</TrnsfrsExemptNonCharRelatedOrg>
      <PartVIOfCompOfHighestPaidEmpl>NONE</PartVIOfCompOfHighestPaidEmpl>
      <PartVIAHghstPaidCntrctProfSer>NONE</PartVIAHghstPaidCntrctProfSer>
      <FiledScheduleA>1</FiledScheduleA>
    </IRS990EZ>
    <IRS990ScheduleA documentId="RetDoc1039100001">
      <PubliclySupportedOrg509a2>X</PubliclySupportedOrg509a2>
      <GiftsGrantsContribReceived509>
        <CurrentTaxYearMinus4Years>34450</CurrentTaxYearMinus4Years>
        <CurrentTaxYearMinus3Years>37575</CurrentTaxYearMinus3Years>
        <CurrentTaxYearMinus2Years>46560</CurrentTaxYearMinus2Years>
        <CurrentTaxYearMinus1Year>42583</CurrentTaxYearMinus1Year>
        <CurrentTaxYear>34083</CurrentTaxYear>
        <Total>195251</Total>
      </GiftsGrantsContribReceived509>
      <Total509>
        <CurrentTaxYearMinus4Years>34450</CurrentTaxYearMinus4Years>
        <CurrentTaxYearMinus3Years>37575</CurrentTaxYearMinus3Years>
        <CurrentTaxYearMinus2Years>46560</CurrentTaxYearMinus2Years>
        <CurrentTaxYearMinus1Year>42583</CurrentTaxYearMinus1Year>
        <CurrentTaxYear>34083</CurrentTaxYear>
        <Total>195251</Total>
      </Total509>
      <AmtsRecdFromDisqualPersons>
        <Total>0</Total>
      </AmtsRecdFromDisqualPersons>
      <AmtsFromSubstContributors>
        <Total>0</Total>
      </AmtsFromSubstContributors>
      <SupportFromDQPsEtc>
        <Total>0</Total>
      </SupportFromDQPsEtc>
      <PublicSupportTotal509>195251</PublicSupportTotal509>
      <GrossInvestmentIncome509>
        <CurrentTaxYearMinus4Years>122</CurrentTaxYearMinus4Years>
        <CurrentTaxYearMinus3Years>28</CurrentTaxYearMinus3Years>
        <CurrentTaxYearMinus2Years>17</CurrentTaxYearMinus2Years>
        <CurrentTaxYearMinus1Year>14</CurrentTaxYearMinus1Year>
        <CurrentTaxYear>3</CurrentTaxYear>
        <Total>184</Total>
      </GrossInvestmentIncome509>
      <InvestmentIncomeAndUBTI>
        <CurrentTaxYearMinus4Years>122</CurrentTaxYearMinus4Years>
        <CurrentTaxYearMinus3Years>28</CurrentTaxYearMinus3Years>
        <CurrentTaxYearMinus2Years>17</CurrentTaxYearMinus2Years>
        <CurrentTaxYearMinus1Year>14</CurrentTaxYearMinus1Year>
        <CurrentTaxYear>3</CurrentTaxYear>
        <Total>184</Total>
      </InvestmentIncomeAndUBTI>
      <TotalSupportTotal>
        <CurrentTaxYearMinus4Years>34572</CurrentTaxYearMinus4Years>
        <CurrentTaxYearMinus3Years>37603</CurrentTaxYearMinus3Years>
        <CurrentTaxYearMinus2Years>46577</CurrentTaxYearMinus2Years>
        <CurrentTaxYearMinus1Year>42597</CurrentTaxYearMinus1Year>
        <CurrentTaxYear>34086</CurrentTaxYear>
        <Total>195435</Total>
      </TotalSupportTotal>
      <PublicSupportPercentage509>0.99910</PublicSupportPercentage509>
      <PriorYearSupportPercentage>0.99820</PriorYearSupportPercentage>
      <InvestmentIncomePercentage>0.00090</InvestmentIncomePercentage>
      <PriorYrInvestIncomePercentage>0.00180</PriorYrInvestIncomePercentage>
      <ThirtyThreePercntTestsCY509>X</ThirtyThreePercntTestsCY509>
    </IRS990ScheduleA>
    <IRS990ScheduleO documentId="RetDoc1051800001">
      <GeneralExplanation>
        <Identifier>OTHER INVESTMENT INCOME</Identifier>
        <ReturnReference>FORM 990-EZ, PART I, LINE 4</ReturnReference>
        <Explanation>CITIZEN'S BANK 3..</Explanation>
      </GeneralExplanation>
      <GeneralExplanation>
        <Identifier>OTHER EXPENSES</Identifier>
        <ReturnReference>FORM 990-EZ, PART I, LINE 16</ReturnReference>
        <Explanation>DESCRIPTION: MEETINGS EXPENSE. AMOUNT: 27,823. DESCRIPTION: HONORARIUM. AMOUNT: 6,000. DESCRIPTION: OFFICE SUPPORT &amp; SUPPLIES. AMOUNT: 583. DESCRIPTION: FILING FEES. AMOUNT: 50. DESCRIPTION: ACCOUNTING. AMOUNT: 1,100. DESCRIPTION: REGISTRATION ASSISTANT. AMOUNT: 600. DESCRIPTION: WEBSITE FEES. AMOUNT: 2,013. DESCRIPTION: CLERICAL HELP. AMOUNT: 1,000. DESCRIPTION: PRUDENTIAL COMMITTEE. AMOUNT: 1,609. DESCRIPTION: SPEAKER EXPENSES. AMOUNT: 663. DESCRIPTION: BANK CHARGES. AMOUNT: 118. DESCRIPTION: MISCELLANEOUS. AMOUNT: 448. TOTAL TO FORM 990-EZ, LINE 16: 42,007.</Explanation>
      </GeneralExplanation>
    </IRS990ScheduleO>
    <TransferPrsnlBnftContractsDecl documentId="RetDoc2278000001">
      <Declaration>THE ORGANIZATION DID NOT, DURING THE YEAR, RECEIVE ANY FUNDS, DIRECTLY,OR INDIRECTLY, TO PAY PREMIUMS ON A PERSONAL BENEFIT CONTRACT.THE ORGANIZATION, DID NOT, DURING THE YEAR, PAY ANY PREMIUMS, DIRECTLY,OR INDIRECTLY, ON A PERSONAL BENEFIT CONTRACT.</Declaration>
    </TransferPrsnlBnftContractsDecl>
  </ReturnData>
</Return>