﻿<?xml version="1.0" encoding="utf-8"?>
<Return returnVersion="2024v5.0" xmlns="http://www.irs.gov/efile">
  <ReturnHeader binaryAttachmentCnt="0">
    <ReturnTs>2025-11-16T13:47:24Z</ReturnTs>
    <TaxPeriodEndDt>2024-12-31</TaxPeriodEndDt>
    <ReturnTypeCd>990EZ</ReturnTypeCd>
    <TaxPeriodBeginDt>2024-01-01</TaxPeriodBeginDt>
    <Filer>
      <EIN>921553880</EIN>
      <BusinessName>
        <BusinessNameLine1Txt>MARS REVIEW OF BOOKS FOUNDATION</BusinessNameLine1Txt>
      </BusinessName>
      <BusinessNameControlTxt>MARS</BusinessNameControlTxt>
      <USAddress>
        <AddressLine1Txt>680 S Cache Street STE 100-10219</AddressLine1Txt>
        <CityNm>JACKSON</CityNm>
        <StateAbbreviationCd>WY</StateAbbreviationCd>
        <ZIPCd>830010000</ZIPCd>
      </USAddress>
    </Filer>
    <BusinessOfficerGrp>
      <PersonNm>Christopher Catoya</PersonNm>
      <PersonTitleTxt>Vice President</PersonTitleTxt>
      <SignatureDt>2025-11-16</SignatureDt>
    </BusinessOfficerGrp>
    <TaxYr>2024</TaxYr>
    <BuildTS>2025-03-06 01:10:19Z</BuildTS>
  </ReturnHeader>
  <ReturnData documentCnt="5">
    <IRS990EZ documentId="SIMPLE990" documentName="IRS990EZ" referenceDocumentName="IRS990ScheduleO ReasonableCauseExplanation TransfersPersonalBenefitsContractsDeclaration BinaryAttachment">
      <MethodOfAccountingCashInd>X</MethodOfAccountingCashInd>
      <WebsiteAddressTxt>https://marsreview.org</WebsiteAddressTxt>
      <Organization501c3Ind referenceDocumentId="ScheduleA" referenceDocumentName="IRS990ScheduleA">X</Organization501c3Ind>
      <TypeOfOrganizationCorpInd>X</TypeOfOrganizationCorpInd>
      <GrossReceiptsAmt>67107</GrossReceiptsAmt>
      <ContributionsGiftsGrantsEtcAmt>43638</ContributionsGiftsGrantsEtcAmt>
      <ProgramServiceRevenueAmt>0</ProgramServiceRevenueAmt>
      <MembershipDuesAmt>10461</MembershipDuesAmt>
      <InvestmentIncomeAmt>0</InvestmentIncomeAmt>
      <SaleOfAssetsGrossAmt>0</SaleOfAssetsGrossAmt>
      <GainOrLossFromSaleOfAssetsAmt>0</GainOrLossFromSaleOfAssetsAmt>
      <GamingGrossIncomeAmt referenceDocumentName="IRS990ScheduleG">0</GamingGrossIncomeAmt>
      <FundraisingGrossIncomeAmt referenceDocumentName="IRS990ScheduleG">0</FundraisingGrossIncomeAmt>
      <SpecialEventsDirectExpensesAmt>0</SpecialEventsDirectExpensesAmt>
      <SpecialEventsNetIncomeLossAmt>0</SpecialEventsNetIncomeLossAmt>
      <GrossSalesOfInventoryAmt>13008</GrossSalesOfInventoryAmt>
      <CostOfGoodsSoldAmt>1651</CostOfGoodsSoldAmt>
      <GrossProfitLossSlsOfInvntryAmt>11357</GrossProfitLossSlsOfInvntryAmt>
      <OtherRevenueTotalAmt>0</OtherRevenueTotalAmt>
      <TotalRevenueAmt>65456</TotalRevenueAmt>
      <BenefitsPaidToOrForMembersAmt>0</BenefitsPaidToOrForMembersAmt>
      <SalariesOtherCompEmplBnftAmt>60616</SalariesOtherCompEmplBnftAmt>
      <FeesAndOtherPymtToIndCntrctAmt>9370</FeesAndOtherPymtToIndCntrctAmt>
      <OccupancyRentUtltsAndMaintAmt>0</OccupancyRentUtltsAndMaintAmt>
      <PrintingPublicationsPostageAmt>1616</PrintingPublicationsPostageAmt>
      <TotalExpensesAmt>71602</TotalExpensesAmt>
      <ExcessOrDeficitForYearAmt>-6146</ExcessOrDeficitForYearAmt>
      <NetAssetsOrFundBalancesBOYAmt>-3376</NetAssetsOrFundBalancesBOYAmt>
      <NetAssetsOrFundBalancesEOYAmt>-9522</NetAssetsOrFundBalancesEOYAmt>
      <InfoInScheduleOPartIIInd>X</InfoInScheduleOPartIIInd>
      <CashSavingsAndInvestmentsGrp>
        <BOYAmt>4458</BOYAmt>
        <EOYAmt>3188</EOYAmt>
      </CashSavingsAndInvestmentsGrp>
      <OtherAssetsTotalDetail>
        <BOYAmt>0</BOYAmt>
        <EOYAmt>7059</EOYAmt>
      </OtherAssetsTotalDetail>
      <Form990TotalAssetsGrp>
        <BOYAmt>4458</BOYAmt>
        <EOYAmt>10247</EOYAmt>
      </Form990TotalAssetsGrp>
      <SumOfTotalLiabilitiesGrp>
        <BOYAmt>7834</BOYAmt>
        <EOYAmt>6222</EOYAmt>
      </SumOfTotalLiabilitiesGrp>
      <NetAssetsOrFundBalancesGrp>
        <BOYAmt>-3376</BOYAmt>
        <EOYAmt>4025</EOYAmt>
      </NetAssetsOrFundBalancesGrp>
      <PrimaryExemptPurposeTxt>The mission of the Mars Review of Books Foundation is to encourage and foster public appreciation of the literary arts and global understanding of critical public policy issues through the publication of a magazine and books, and through the hosting of events and symposia.</PrimaryExemptPurposeTxt>
      <ProgramSrvcAccomplishmentGrp>
        <DescriptionProgramSrvcAccomTxt>Production and publication of Mars Review of Books Issue 5 and 6</DescriptionProgramSrvcAccomTxt>
        <ProgramServiceExpensesAmt>44209</ProgramServiceExpensesAmt>
      </ProgramSrvcAccomplishmentGrp>
      <ProgramSrvcAccomplishmentGrp>
        <DescriptionProgramSrvcAccomTxt>Production of the The Mars Review of Books Podcast</DescriptionProgramSrvcAccomTxt>
        <ProgramServiceExpensesAmt>22775</ProgramServiceExpensesAmt>
      </ProgramSrvcAccomplishmentGrp>
      <ProgramSrvcAccomplishmentGrp>
        <DescriptionProgramSrvcAccomTxt>Production of Aaron Swartz Statue (Fiscal Sponsorship)</DescriptionProgramSrvcAccomTxt>
        <ProgramServiceExpensesAmt>21866</ProgramServiceExpensesAmt>
      </ProgramSrvcAccomplishmentGrp>
      <TotalProgramServiceExpensesAmt>88850</TotalProgramServiceExpensesAmt>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm referenceDocumentName="CompensationExplanation">Noah Kumin</PersonNm>
        <TitleTxt>Executive Director</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>40.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>31723</CompensationAmt>
        <EmployeeBenefitProgramAmt>0</EmployeeBenefitProgramAmt>
        <ExpenseAccountOtherAllwncAmt>0</ExpenseAccountOtherAllwncAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm referenceDocumentName="CompensationExplanation">Nick Simmons</PersonNm>
        <TitleTxt>President</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>2.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
        <EmployeeBenefitProgramAmt>0</EmployeeBenefitProgramAmt>
        <ExpenseAccountOtherAllwncAmt>0</ExpenseAccountOtherAllwncAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm referenceDocumentName="CompensationExplanation">Christopher Catoya</PersonNm>
        <TitleTxt>Vice President</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>2.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
        <EmployeeBenefitProgramAmt>0</EmployeeBenefitProgramAmt>
        <ExpenseAccountOtherAllwncAmt>0</ExpenseAccountOtherAllwncAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <OfficerDirectorTrusteeEmplGrp>
        <PersonNm referenceDocumentName="CompensationExplanation">Weyland Joyner</PersonNm>
        <TitleTxt>Secretary</TitleTxt>
        <AverageHrsPerWkDevotedToPosRt>0.00</AverageHrsPerWkDevotedToPosRt>
        <CompensationAmt>0</CompensationAmt>
        <EmployeeBenefitProgramAmt>0</EmployeeBenefitProgramAmt>
        <ExpenseAccountOtherAllwncAmt>0</ExpenseAccountOtherAllwncAmt>
      </OfficerDirectorTrusteeEmplGrp>
      <InfoInScheduleOPartVInd>X</InfoInScheduleOPartVInd>
      <ActivitiesNotPreviouslyRptInd>true</ActivitiesNotPreviouslyRptInd>
      <ChgMadeToOrgnzngDocNotRptInd>true</ChgMadeToOrgnzngDocNotRptInd>
      <OrganizationHadUBIInd>false</OrganizationHadUBIInd>
      <SubjectToProxyTaxInd referenceDocumentName="IRS990ScheduleC">false</SubjectToProxyTaxInd>
      <OrganizationDissolvedEtcInd referenceDocumentId="ScheduleN" referenceDocumentName="IRS990ScheduleN BinaryAttachment">true</OrganizationDissolvedEtcInd>
      <Form1120PolFiledInd>false</Form1120PolFiledInd>
      <MadeLoansToFromOfficersInd>false</MadeLoansToFromOfficersInd>
      <TaxImposedUnderIRC4911Amt>0</TaxImposedUnderIRC4911Amt>
      <TaxImposedUnderIRC4912Amt>0</TaxImposedUnderIRC4912Amt>
      <TaxImposedUnderIRC4955Amt>0</TaxImposedUnderIRC4955Amt>
      <EngagedInExcessBenefitTransInd referenceDocumentName="IRS990ScheduleL">false</EngagedInExcessBenefitTransInd>
      <TaxImposedOnOrganizationMgrAmt>0</TaxImposedOnOrganizationMgrAmt>
      <TaxReimbursedByOrganizationAmt>0</TaxReimbursedByOrganizationAmt>
      <ProhibitedTaxShelterTransInd>false</ProhibitedTaxShelterTransInd>
      <StatesWhereCopyOfReturnIsFldCd>WY</StatesWhereCopyOfReturnIsFldCd>
      <BooksInCareOfDetail>
        <PersonNm>Noah Kumin</PersonNm>
        <USAddress>
          <AddressLine1Txt>59 W 9th Street</AddressLine1Txt>
          <AddressLine2Txt>Apartment 2</AddressLine2Txt>
          <CityNm>New York City</CityNm>
          <StateAbbreviationCd>NY</StateAbbreviationCd>
          <ZIPCd>10011</ZIPCd>
        </USAddress>
        <PhoneNum>9173046765</PhoneNum>
      </BooksInCareOfDetail>
      <ForeignFinancialAccountInd>false</ForeignFinancialAccountInd>
      <ForeignOfficeInd>false</ForeignOfficeInd>
      <DonorAdvisedFndsInd>false</DonorAdvisedFndsInd>
      <OperateHospitalInd>false</OperateHospitalInd>
      <TanningServicesProvidedInd>false</TanningServicesProvidedInd>
      <RelatedOrganizationCtrlEntInd>false</RelatedOrganizationCtrlEntInd>
      <TransactionWithControlEntInd>false</TransactionWithControlEntInd>
      <PoliticalCampaignActyInd referenceDocumentName="IRS990ScheduleC">false</PoliticalCampaignActyInd>
      <LobbyingActivitiesInd referenceDocumentName="IRS990ScheduleC">false</LobbyingActivitiesInd>
      <SchoolOperatingInd referenceDocumentName="IRS990ScheduleE">false</SchoolOperatingInd>
      <TrnsfrExmptNonChrtblRltdOrgInd>false</TrnsfrExmptNonChrtblRltdOrgInd>
      <RelatedOrgSect527OrgInd>false</RelatedOrgSect527OrgInd>
      <CompensationHighestPaidEmplGrp>
        <PersonNm referenceDocumentName="EmployeeCompensationExplanation">Isabel Fenaroli</PersonNm>
        <TitleTxt>Events Coordinator</TitleTxt>
        <AverageHoursPerWeekRt>5.00</AverageHoursPerWeekRt>
        <CompensationAmt>3800</CompensationAmt>
        <EmployeeBenefitsAmt>0</EmployeeBenefitsAmt>
        <ExpenseAccountAmt>0</ExpenseAccountAmt>
      </CompensationHighestPaidEmplGrp>
      <OtherEmployeePaidOver100kCnt>0</OtherEmployeePaidOver100kCnt>
      <PartVIHghstPdCntrctProfSrvcTxt>NONE</PartVIHghstPdCntrctProfSrvcTxt>
      <CntrctRcvdGreaterThan100KCnt>0</CntrctRcvdGreaterThan100KCnt>
    </IRS990EZ>
    <IRS990ScheduleA documentId="ScheduleA" documentName="IRS990ScheduleA">
      <PubliclySupportedOrg509a2Ind>X</PubliclySupportedOrg509a2Ind>
      <SupportedOrganizationsCnt>0</SupportedOrganizationsCnt>
      <GiftsGrantsContrisRcvd509Grp>
        <CurrentTaxYearMinus2YearsAmt>0</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>74067</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>54099</CurrentTaxYearAmt>
        <TotalAmt>128166</TotalAmt>
      </GiftsGrantsContrisRcvd509Grp>
      <GrossReceiptsAdmissionsGrp>
        <CurrentTaxYearMinus1YearAmt>22512</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>11357</CurrentTaxYearAmt>
        <TotalAmt>33869</TotalAmt>
      </GrossReceiptsAdmissionsGrp>
      <Total509Grp>
        <CurrentTaxYearMinus4YearsAmt>0</CurrentTaxYearMinus4YearsAmt>
        <CurrentTaxYearMinus3YearsAmt>0</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>0</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>96579</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>65456</CurrentTaxYearAmt>
        <TotalAmt>162035</TotalAmt>
      </Total509Grp>
      <AmountsRcvdDsqlfyPersonGrp>
        <TotalAmt>0</TotalAmt>
      </AmountsRcvdDsqlfyPersonGrp>
      <SubstantialContributorsAmtGrp>
        <TotalAmt>0</TotalAmt>
      </SubstantialContributorsAmtGrp>
      <SubstAndDsqlfyPrsnsTotGrp>
        <TotalAmt>0</TotalAmt>
      </SubstAndDsqlfyPrsnsTotGrp>
      <PublicSupportTotal509Amt>162035</PublicSupportTotal509Amt>
      <GrossInvestmentIncome509Grp>
        <TotalAmt>0</TotalAmt>
      </GrossInvestmentIncome509Grp>
      <Post1975UBTIGrp>
        <TotalAmt>0</TotalAmt>
      </Post1975UBTIGrp>
      <InvestmentIncomeAndUBTIGrp>
        <CurrentTaxYearMinus4YearsAmt>0</CurrentTaxYearMinus4YearsAmt>
        <CurrentTaxYearMinus3YearsAmt>0</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>0</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>0</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>0</CurrentTaxYearAmt>
        <TotalAmt>0</TotalAmt>
      </InvestmentIncomeAndUBTIGrp>
      <NetIncomeFromOtherUBIGrp>
        <TotalAmt>0</TotalAmt>
      </NetIncomeFromOtherUBIGrp>
      <OtherIncome509Grp>
        <TotalAmt>0</TotalAmt>
      </OtherIncome509Grp>
      <TotalSupportCalendarYearGrp>
        <CurrentTaxYearMinus4YearsAmt>0</CurrentTaxYearMinus4YearsAmt>
        <CurrentTaxYearMinus3YearsAmt>0</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>0</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>96579</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>65456</CurrentTaxYearAmt>
        <TotalAmt>162035</TotalAmt>
      </TotalSupportCalendarYearGrp>
      <First5Years509Ind>X</First5Years509Ind>
      <PublicSupportCY509Pct>1.00000</PublicSupportCY509Pct>
      <PublicSupportPY509Pct>1.00000</PublicSupportPY509Pct>
      <InvestmentIncomeCYPct>0.00000</InvestmentIncomeCYPct>
      <InvestmentIncomePYPct>0.00000</InvestmentIncomePYPct>
    </IRS990ScheduleA>
    <IRS990ScheduleB documentId="ScheduleB" documentName="IRS990ScheduleB">
      <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>
    <IRS990ScheduleN documentId="ScheduleN" documentName="IRS990ScheduleN">
      <DirectorOfSuccessorInd>false</DirectorOfSuccessorInd>
      <EmployeeOfSuccessorInd>false</EmployeeOfSuccessorInd>
      <OwnerOfSuccessorInd>false</OwnerOfSuccessorInd>
      <ReceiveCompensationInd>false</ReceiveCompensationInd>
      <DirectorOfSuccessor2Ind>false</DirectorOfSuccessor2Ind>
      <EmployeeOfSuccessor2Ind>false</EmployeeOfSuccessor2Ind>
      <OwnerOfSuccessor2Ind>false</OwnerOfSuccessor2Ind>
      <ReceiveCompensation2Ind>false</ReceiveCompensation2Ind>
    </IRS990ScheduleN>
    <IRS990ScheduleO documentId="ScheduleO" documentName="IRS990ScheduleO">
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Part II, Line 24</FormAndLineReferenceDesc>
        <ExplanationTxt>The organization holds a limited amount of digital assets in the form of Solana (SOL) tokens and three Urbit Star identifiers received as in-kind contributions. In accordance with the organizations accounting policy and to ensure conservative and reliable financial reporting, digital assets are valued using the lower-of-cost-or-market (LCM) method. Solana holdings were recorded at their fair market value as of December 31, 2024. The Urbit Star assets were recorded at their historical contribution value due to the absence of an active, observable market on the valuation date. Other minor Solana-based tokens held in the organizations wallet were determined to have no measurable or readily determinable market value at year-end and were therefore reported at zero under the LCM policy. The amounts reported on the balance sheet reflect this methodology and represent the organizations best estimate of the realizable value of its digital assets in accordance with responsible financial stewardship and nonprofit reporting standards.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Part V, Line 33</FormAndLineReferenceDesc>
        <ExplanationTxt>Accepting crypto donations and managing the treasury thereof. The account had a net loss of about $16,000 due to crypto risks.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Part V, Line 34</FormAndLineReferenceDesc>
        <ExplanationTxt>Nick Simmons, Christopher Catoya, and Weyland Joyner were added to the board. Josh Lehman and Anthony Arroyo were removed from the board.</ExplanationTxt>
      </SupplementalInformationDetail>
    </IRS990ScheduleO>
  </ReturnData>
</Return>