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        <ReturnReference>PART V, LINE 4:</ReturnReference>
        <Explanation>THE ASSOCIATION CLASSIFIES AS PERMANENTLY RESTRICTED NET ASSETS (A) THE ORIGINAL VALUE OF GIFTS DONATED TO THE PERMANENT ENDOWMENT, (B) THE ORIGINAL VALUE OF SUBSEQUENT GIFTS TO THE PERMANENT ENDOWMENT, AND (C) ACCUMULATIONS TO THE PERMANENT ENDOWMENT MADE IN ACCORDANCE WITH THE DIRECTION OF THE APPLICABLE DONOR GIFT INSTRUMENT AT THE TIME THE ACCUMULATION IS ADDED TO THE FUND. THE REMAINING PORTION OF THE DONOR-RESTRICTED ENDOWMENT FUND THAT IS NOT CLASSIFIED IN PERMANENTLY RESTRICTED NET ASSETS IS CLASSIFIED AS TEMPORARILY RESTRICTED NET ASSETS, UNTIL THOSE AMOUNTS ARE APPROPRIATED FOR EXPENDITURES BY THE ASSOCIATION IN A MANNER CONSISTENT WITH THE STANDARD OF PRUDENCE PRESCRIBED BY UPMIFA. BOARD DESIGNATED NET ASSETS AT DECEMBER 31, 2009 AND 2008, WITH EXECUTIVE BOARD APPROVAL, ARE AVAILABLE TO SUPPORT SPECIAL ACTIVITIES IN THE AREA OF PHYSICS TEACHING AND TO SUPPORT THE ADVANCEMENT OF PHYSICS EDUCATION.</Explanation>
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        <ReturnReference>PART X:</ReturnReference>
        <Explanation>THE ASSOCIATION IS GENERALLY EXEMPT FROM FEDERAL INCOME TAXES UNDER THE PROVISIONS OF SECTION 501(C)(3) OF THE INTERNAL REVENUE CODE. UNDER CURRENT INTERNAL REVENUE SERVICE (IRS) REGULATIONS, ADVERTISING AND OTHER NON-EXEMPT REVENUE EARNED IS SUBJECT TO UNRELATED BUSINESS INCOME TAX. FOR THE YEARS ENDED DECEMBER 31, 2010 AND 2009, THE ASSOCIATION HAD NO NET UNRELATED BUSINESS INCOME. THE ASSOCIATION FOLLOWS THE ACCOUNTING STANDARD ON ACCOUNTING FOR UNCERTAINTY IN INCOME TAXES, WHICH ADDRESSES THE DETERMINATION OF WHETHER TAX BENEFITS CLAIMED OR EXPECTED TO BE CLAIMED ON A TAX RETURN SHOULD BE RECORDED IN THE FINANCIAL STATEMENTS. UNDER THIS GUIDANCE, THE ASSOCIATION MAY RECOGNIZE THE TAX BENEFIT FROM AN UNCERTAIN TAX POSITION ONLY IF IT IS MORE-LIKELY-THAN-NOT THAT THE TAX POSITION WILL BE SUSTAINED ON EXAMINATION BY TAXING AUTHORITIES, BASED ON THE TECHNICAL MERITS OF THE POSITION. THE TAX BENEFITS RECOGNIZED IN THE FINANCIAL STATEMENTS FROM SUCH A POSITION ARE MEASURED BASED ON THE LARGEST BENEFIT THAT HAS A GREATER THAN 50 PERCENT LIKELIHOOD OF BEING REALIZED UPON ULTIMATE SETTLEMENT. THE GUIDANCE ON ACCOUNTING FOR UNCERTAINTY IN INCOME TAXES ALSO ADDRESSES DE-RECOGNITION, CLASSIFICATION, INTEREST AND PENALTIES ON INCOME TAXES, AND ACCOUNTING IN INTERIM PERIODS. THE ASSOCIATION HAD NO SUCH POSITIONS RECORDED IN THE FINANCIAL STATEMENTS AT DECEMBER 31, 2010. GENERALLY, THE ASSOCIATION IS NO LONGER SUBJECT TO U.S. FEDERAL INCOME TAX POSITIONS BY TAX AUTHORITIES FOR YEARS BEFORE 2007.</Explanation>
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        <Identifier>PROCEDURE FOR MONITORING GRANTS IN THE U.S.:</Identifier>
        <ReturnReference>PART I, LINE 2:</ReturnReference>
        <Explanation>SCHEDULE I, PART I, LINE 2: IT IS THE GOAL OF THE AAPT TO ENCOURAGE HIGH SCHOOL TEACHERS TO EXPERIMENT AND IMPROVE ON THEIR TEACHING PRACTICES. IT IS OUR BELIEF THAT AS TEACHING PRACTICE IMPROVES, THEN PHYSICS ENROLLMENT AND EXCITEMENT AMONG STUDENTS INCREASE. AS A RESULT, WE OFFER THE HIGH SCHOOL PHYSICS TEACHER GRANT. WE HOPE THAT THIS GRANT CAN PROVIDE THE FUNDS TO KICK START THE IMPLEMENTATION OF THESE PRACTICES. THE GRANT(S) ARE GIVEN EACH YEAR TO TEACHERS WHOSE PROPOSAL MEETS THE GOAL OF THE GRANT. THAT IS, THE PROCEDURE SHOULD RESULT IN BETTER TEACHING PRACTICE, STUDENT UNDERSTANDING AND INTEREST, AND/OR INCREASED ENROLLMENT.ALSO, THE PROPOSAL SHOULD CONTAIN SOME INNOVATIVE IDEAS. FOR EXAMPLE, THE PROPOSAL MAY USE A NEW TEACHING METHOD OR AN ADAPTATION OF AN EXISTING IDEA. THE AAPT EXECUTIVE BOARD OFFERS SCHOLARSHIPS FOR FUTURE HIGH SCHOOL PHYSICS TEACHERS. THESE SCHOLARSHIPS, SUPPORTED BY AN ENDOWMENT FUNDED BY BARBARA LOTZE, ARE AVAILABLE ONLY TO U.S. CITIZENS ATTENDING U.S. SCHOOLS. UNDERGRADUATE STUDENTS ENROLLED, OR PLANNING TO ENROLL, IN PHYSICS TEACHER PREPARATION CURRICULA AND HIGH SCHOOL SENIORS ENTERING SUCH PROGRAMS ARE ELIGIBLE. SUCCESSFUL APPLICANTS RECEIVE A STIPEND OF UP TO $2,000. THE SCHOLARSHIP MAY BE GRANTED TO AN INDIVIDUAL FOR EACH OF FOUR YEARS. APPLICATIONS WILL BE ACCEPTED AT ANY TIME AND WILL BE CONSIDERED FOR RECOMMENDATION TO THE EXECUTIVE BOARD AT EACH AAPT WINTER MEETING. ALL APPLICATIONS IN WHICH ALL MATERIALS, INCLUDING LETTERS OF RECOMMENDATION, ARE RECEIVED BY DECEMBER 1 WILL BE CONSIDERED FOR RECOMMENDATION AT THE WINTER MEETING OF THE AAPT EXECUTIVE BOARD.</Explanation>
      </Form990ScheduleIPartIV>
    </IRS990ScheduleI>
    <IRS990ScheduleJ documentId="RetDoc1042400001">
      <CompensationCommittee>X</CompensationCommittee>
      <CompensationSurvey>X</CompensationSurvey>
      <BoardOrCommitteeApproval>X</BoardOrCommitteeApproval>
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      <Form990ScheduleJPartII>
        <NamePerson>WARREN W HEIN</NamePerson>
        <BaseCompensationFilingOrg>173352</BaseCompensationFilingOrg>
        <CompBasedOnRelatedOrgs>0</CompBasedOnRelatedOrgs>
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      <GeneralExplanation>
        <Identifier>FORM 990, PART VI, SECTION A, LINE 6</Identifier>
        <Explanation>THE MEMBERSHIP OF THE ASSOCIATION IS MADE UP OF FOUR YEAR UNIVERSITY/COLLEGE AND TWO YEAR COLLEGE PROFESSORS AND EDUCATORS OF THE PHYSICS SCIENCES IN THE UNITED STATES AND INTERNATIONALLY. THE MEMBERSHIP ALSO INCLUDES HIGH SCHOOL EDUCATORS, STUDENTS OF PHYSICS/SCIENCES AND RETIRED MEMBERS IN THE UNITED STATES AND INTERNATIONALLY.</Explanation>
      </GeneralExplanation>
      <GeneralExplanation>
        <Identifier>FORM 990, PART VI, SECTION A, LINE 7A</Identifier>
        <Explanation>THE NOMINATION COMMITTEE WILL NOMINATE MEMBERS OF THE GOVERNING BODY WHO THEN ARE ELECTED BY THE GENERAL MEMBERSHIP BY BALLOT.</Explanation>
      </GeneralExplanation>
      <GeneralExplanation>
        <Identifier>FORM 990, PART VI, SECTION B, LINE 11</Identifier>
        <Explanation>THE FORM 990 WILL BE POSTED ON THE BOARD WEB SITE AND INFORMED BY E-MAIL. THE BOARD MEMBER IS ASKED TO INQUIRE, REVIEW AND ASK QUESTIONS RELATED TO THE TAX RETURN. AFTER ALL BOARD ISSUES HAVE BEEN RESPONDED TO THE 990 TAX RETURN WILL BE FILED.</Explanation>
      </GeneralExplanation>
      <GeneralExplanation>
        <ReturnReference>FORM 990, PART VI, SECTION B, LINE 12C</ReturnReference>
        <Explanation>THE GOVERNING BODY IS REQUIRED TO RESPOND ELECTRONICALLY TO THE CONFLICT OF INTEREST QUESTIONNAIRE ON A YEARLY BASIS.</Explanation>
      </GeneralExplanation>
      <GeneralExplanation>
        <ReturnReference>FORM 990, PART VI, SECTION B, LINE 15</ReturnReference>
        <Explanation>THE COMPENSATION COMMITTEE REVIEWS COMPENSATION OF THE EXECUTIVE OFFICER USING COMPARABLE DATA OF SLIMIER SIZE NONPROFIT ORGANIZATIONS, USING PUBLISHED SALARY GUIDES.</Explanation>
      </GeneralExplanation>
      <GeneralExplanation>
        <ReturnReference>FORM 990, PART VI, SECTION C, LINE 19</ReturnReference>
        <Explanation>THE DOCUMENTS ARE POSTED ON THE ORGANIZATION'S WEBSITE AND COPIES ARE PROVIDED UPON REQUEST; INSPECTIONS OF DOCUMENTS MAY BE MADE AT THE ASSOCIATION'S OFFICE BY APPOINTMENT.</Explanation>
      </GeneralExplanation>
      <GeneralExplanation>
        <Identifier>CHANGES IN NET ASSETS OR FUND BALANCES:</Identifier>
        <ReturnReference>FORM 990, PART XI, LINE 5:</ReturnReference>
        <Explanation>NET UNREALIZED GAINS ON INVESTMENTS: 422,111.</Explanation>
      </GeneralExplanation>
    </IRS990ScheduleO>
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      <Form990ScheduleRPartII>
        <NameOfDisregardedEntity>
          <BusinessNameLine1>AMERICAN CENTER FOR PHYSICS</BusinessNameLine1>
        </NameOfDisregardedEntity>
        <AddressUS>
          <AddressLine1>1 PHYSICS ELLIPSE</AddressLine1>
          <City>COLLEGE PARK</City>
          <State>MD</State>
          <ZIPCode>20740</ZIPCode>
        </AddressUS>
        <EIN>521712905</EIN>
        <PrimaryActivities>OPERATION OF FACILITY - NATIONAL CENTER OF PHYSICS</PrimaryActivities>
        <LegalDomicileState>MD</LegalDomicileState>
        <ExemptCodeSection>501(C)(3)</ExemptCodeSection>
        <PublicCharityStatus>LINE 11B, II</PublicCharityStatus>
        <DirectControllingEntityNA>N/A</DirectControllingEntityNA>
        <ControlledOrg>0</ControlledOrg>
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      <GiftGrantOrCapContrToOtherOrg>0</GiftGrantOrCapContrToOtherOrg>
      <GiftGrantOrCapContrFrOtherOrg>0</GiftGrantOrCapContrFrOtherOrg>
      <LoansOrGuaranteesToOtherOrg>0</LoansOrGuaranteesToOtherOrg>
      <LoansOrGuaranteesFromOtherOrg>0</LoansOrGuaranteesFromOtherOrg>
      <SaleOfAssetsToOtherOrg>0</SaleOfAssetsToOtherOrg>
      <PurchaseOfAssetsFromOtherOrg>0</PurchaseOfAssetsFromOtherOrg>
      <ExchangeOfAssets>0</ExchangeOfAssets>
      <RentalOfFacilitiesToOtherOrgs>1</RentalOfFacilitiesToOtherOrgs>
      <RentalOfFacilitiesFrOtherOrgs>0</RentalOfFacilitiesFrOtherOrgs>
      <PerformOfServicesForOtherOrgs>0</PerformOfServicesForOtherOrgs>
      <PerformOfServicesByOtherOrgs>0</PerformOfServicesByOtherOrgs>
      <SharingOfFacilities>0</SharingOfFacilities>
      <SharingOfPaidEmployees>0</SharingOfPaidEmployees>
      <ReimbursementPaidToOtherOrg>0</ReimbursementPaidToOtherOrg>
      <ReimbursementPaidByOtherOrg>0</ReimbursementPaidByOtherOrg>
      <OtherTransferToOtherOrg>0</OtherTransferToOtherOrg>
      <OtherTransferFromOtherOrg>0</OtherTransferFromOtherOrg>
      <TransactionsRelatedOrgsTable>
        <NameOfOtherOrganization>
          <BusinessNameLine1>AMERICAN CENTER FOR PHYSICS INC</BusinessNameLine1>
        </NameOfOtherOrganization>
        <TransactionType>I</TransactionType>
        <AmountInvolved>633059</AmountInvolved>
        <MethodOfAmtDetermination>COST</MethodOfAmtDetermination>
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