Nonprofit · EIN 52-1073697
PHILOSOPHICAL SOCIETY OF WASHINGTON
Tax-exempt · WASHINGTON, DC 20008
Financials
| Year ended | Form | Revenue | Expenses | Net income | Total assets | Liabilities | Net assets |
|---|---|---|---|---|---|---|---|
| June 30, 2025 | 990 | $160,997 | $116,162 | $44,835 | $686,649 | $23,066 | $663,583 |
| June 30, 2024 | 990 | $132,569 | $101,091 | $31,478 | $597,178 | $19,942 | $577,236 |
Financial details: 990 for the year ended June 30, 2025
Revenue
- Contributions, gifts and grants
- $74,426
- Membership dues
- $15,824
- Program service revenue
- $52,045
- Investment income
- $14,564
- Net income from sales of inventory
- $511
- Other revenue
- $19,962
Expenses
- Grants and similar amounts paid
- $0
- Salaries, compensation and benefits (total)
- $0
- Professional fundraising fees
- $0
- Legal fees
- $315
- Depreciation
- $6,043
- Program services (functional)
- $101,922
- Management and general (functional)
- $12,765
- Fundraising (functional)
- $1,475
Balance sheet and other
- Total assets, start of year
- $597,178
- Total assets, end of year
- $686,649
- Total liabilities, end of year
- $23,066
- Net assets, end of year
- $663,583
- Land, buildings and equipment
- $17,480
- Publicly traded securities
- $592,212
- Net assets without donor restrictions
- $573,583
- Net assets with donor restrictions
- $90,000
- Gross receipts
- $161,154
- Employees
- 0
- Volunteers
- 20
- Year formed
- 1871
- State of legal domicile
- DC
From the e-filed returns the IRS publishes as XML (latest three processing years; amended returns replace the original). PDF copies at the IRS.
Officers, directors and key employees
As listed on the 990 for the year ended June 30, 2025, highest compensation first.
| Name | Title | Hours / week | Compensation |
|---|---|---|---|
| Larry Millstein | President and Program Director Trustee or director, Officer | 20 | $0 |
| Robert Thompson | Vice President (to March 2025); Treasurer Trustee or director, Officer | 5 | $0 |
| Robin Taylor | Corresponding Secretary & Executive Director Trustee or director, Officer | 20 | $0 |
| Scott Mathews | Recording Secretary Trustee or director, Officer | 5 | $0 |
| Brett Magaram | Treasurer (to March 2025) Trustee or director, Officer | 3 | $0 |
| Anne McQueen | Member at Large Trustee or director | 3 | $0 |
| Carey Lisse | Member at Large (to March 2025); Vice President Trustee or director, Officer | 3 | $0 |
| Lloyd Mitchell | Membership Director Trustee or director | 3 | $0 |
| William Blair | Member at Large Trustee or director | 3 | $0 |
| Kirsten Wunder | Special Projects Director Trustee or director | 3 | $0 |
990 for the year ended June 30, 2024: 11 people
| Name | Title | Hours / week | Compensation |
|---|---|---|---|
| Larry Millstein | President and Program Director Trustee or director, Officer | 20 | $0 |
| Robert Thompson | Vice President Trustee or director, Officer | 3 | $0 |
| Robin Taylor | Corresponding Secretary Trustee or director, Officer | 20 | $0 |
| Scott Mathews | Recording Secretary Trustee or director, Officer | 5 | $0 |
| Brett Magaram | Treasurer Trustee or director, Officer | 3 | $0 |
| Anne McQueen | Member at Large Trustee or director | 5 | $0 |
| Carey Lisse | Member at Large Trustee or director | 3 | $0 |
| Lloyd Mitchell | Membership Director Trustee or director | 3 | $0 |
| Conor Nixon | Member at Large (to July 2023) Trustee or director | 3 | $0 |
| James Heelan | Special Projects Director (to December 2023) Trustee or director | 3 | $0 |
| Cameo Lance | Recording Secretary (to December 2023) Trustee or director, Officer | 5 | $0 |
Address and contacts
- Address (IRS master file)
- 2121 MASSACHUSETTS AVE NW, WASHINGTON, DC 20008-3639
- In care of
- % COSMOS CLUB
- Mailing address (990-N for 2014)
- 2121 Massachusetts Ave NW, Washington DC 20008
- Principal officer (990 for 2024)
- Larry Millstein, c/o Cosmos Club, 2121 Massachusetts Ave NW, Washington, DC 20008
- Principal officer (990-N for 2014)
- Larry S Millstein, 4053 41st St N, McLean VA 22101
- Signed the 990
- Larry Millstein, President
- Phone
- (202) 599-2858
- Website
- www.philsoc.org
Mission
Educational, scientific, and professional society organized in 1871 by Joseph Henry (the first secretary of the Smithsonian) providing science lectures, education, and discussion to its members and the public for the promotion of science, the advancement of learning, and the free exchange of views among its members and attendees on scientific subjects. Lectures and the accompanying discussion are recorded and made available to all, free of charge, on the Society's video channels.
Program accomplishments
- PSW Science is one of the oldest scientific societies in Washington, DC founded in 1871 by Joseph Henry, the first Secretary of the Smithsonian Institution. It presents 16-20 science lectures a year, free and open to the public with discussion during and after the lecture. Approximately 1200 to 1500 people attend each year; individual lecture attendance is approximately 80-200. There is a pre-lecture reception and dinner with the speaker before the lecture; dinner attendees pay an event fee to cover costs; attendance is 20-50 per lecture. The receptions and dinners are designed to provide ample opportunity for interaction among the attendees with the speaker, and many collaborations have been initiated at these gatherings. The lectures address the scientific issues of the day and there is robust discussion before, during, and after the lecture. The lecturers are usually leading scientists in the field or leaders of important scientific organizations. The lectures are in-depth and sophisticated, about an hour in length followed by a robust question and answer period of approximately 30 to 60 minutes. The lectures are geared to address three levels of discourse: professional scientists in the field of the lecturer, scientists in other fields, and others who are interested in the topic but are not scientific specialists. The lectures are not basic summaries or short popular-style snippets of information, but are designed to address the substantive technical nature of the work being presented. PSW Science has a strong interdisciplinary educational mission to bring together scientists and others who work in diverse fields and diverse institutions of academia, industry, and government so that they will benefit from discussion with others outside of their fields and institutions. PSW Science engages all areas of science, including both physical and life science, with lectures in the areas of astronomy, planetary and earth science, cosmology, biomedical science, chemistry and biochemistry, computer science, artificial intelligence, biology, and engineering, to name just a few. Members and regular attendees work in industry, government, and academia. Many members and regular attendees work for or with federal agencies, such as NASA, NIST, NSF, DOE, and NIH. Members and regular attendees include students, young-career professionals, and established scientists. One of the primary goals of PSW Science is to provide an opportunity for students and younger professionals to meet and interact with prominent scientists.Expenses $87,895 · revenue $52,045
- PSW Science's educational outreach is substantial and multi-faceted. It live-streams its science lectures and posts them to its website and PSW Science YouTube and Vimeo channels, where the videos have been viewed over a million times. In addition, approximately 20-100 people watch each live stream and participate in real-time in the discussion. There are hundreds of thousands of views of the lectures each year on the PSW Science channels with viewers located throughout the world. These viewers have the opportunity to see leading scientists in a field discuss the most important scientific issues of the day. This is a core part of the mission of PSW Science -- to provide science education to as many people as possible without charge.Expenses $14,027
What it must file and when
IRS records say it files Form 990 or 990-EZ. Based on its last return; a smaller organization may file the 990-N. Its accounting year ends in June, so each return is due on the 15th day of the 5th month after that.
| Tax year | Year ended | Due | IRS public records |
|---|---|---|---|
| 2025 | June 30, 2026 | November 16, 2026 | Not due yet |
| 2024 | June 30, 2025 | November 17, 2025 | 990 on file |
| 2023 | June 30, 2024 | November 15, 2024 | 990 on file |
IRS record
- EIN
- 52-1073697
- Tax-exempt status
- 501(c)(3): Charitable, religious, educational or scientific organization
- Foundation status
- Publicly supported organization (509(a)(2))
- Donations deductible (Pub 78)
- Public charity, 50% deduction limit
- Exempt since
- 1977
- Accounting year ends
- June
- Files
- Form 990 or 990-EZ
- Assets (IRS master file)
- $686,649
- Income (IRS master file)
- $161,154
Filing history
| Form | Year ended | Revenue | Expenses | Assets | Return |
|---|---|---|---|---|---|
| 990 | June 2025 | $160,997 | $116,162 | $686,649 | IRS |
| 990 | June 2024 | $132,569 | $101,091 | $597,178 | XML |
| 990 | June 2023 | $94,246 | $82,290 | $512,675 | IRS |
| 990-EZ | June 2022 | – | – | – | IRS |
| 990-N for 2014 Officer: Larry S Millstein | June 30, 2015 | ≤ $50,000 receipts | – | – | e-Postcard |
990-N: the IRS bulk file holds only the latest e-Postcard per organization; earlier years come from archived copies of that file since 2020 and can have gaps (the IRS e-Postcard search lists every one). 990, 990-EZ, 990-PF, 990-T: every e-filed return in the IRS e-file index since 2019; XML for the latest three processing years, amounts from the IRS Statistics of Income extracts before that. PDF copies and determination letters at the IRS (search EIN 52-1073697).
Questions about PHILOSOPHICAL SOCIETY OF WASHINGTON
- What is the EIN of PHILOSOPHICAL SOCIETY OF WASHINGTON?
- The employer identification number (EIN) of PHILOSOPHICAL SOCIETY OF WASHINGTON is 52-1073697.
- Is PHILOSOPHICAL SOCIETY OF WASHINGTON tax-exempt?
- Yes. The IRS lists it as tax-exempt under section 501(c)(3) since 1977.
- Are donations to PHILOSOPHICAL SOCIETY OF WASHINGTON tax-deductible?
- Yes. It is listed in IRS Publication 78 (Public charity, 50% deduction limit).
- Which annual return does PHILOSOPHICAL SOCIETY OF WASHINGTON file?
- Form 990 or 990-EZ. Based on its last return; a smaller organization may file the 990-N.
- When is the next return of PHILOSOPHICAL SOCIETY OF WASHINGTON due?
- The return for tax year 2025 (the year ending June 30, 2026) is due November 16, 2026. Form 8868 extends it by six months; the 990-N cannot be extended.
- When did PHILOSOPHICAL SOCIETY OF WASHINGTON last file with the IRS?
- The latest return in the IRS public files is the 990 for the year ended June 2025.
- Who is the principal officer of PHILOSOPHICAL SOCIETY OF WASHINGTON?
- The 990 for the year ended June 30, 2025 names Larry Millstein.
- Who are the officers and directors of PHILOSOPHICAL SOCIETY OF WASHINGTON?
- The 990 for the year ended June 30, 2025 lists 10 people; 0 received compensation from the organization.
- How much revenue does PHILOSOPHICAL SOCIETY OF WASHINGTON have?
- On its 990 for the year ended June 30, 2025 it reported revenue of $160,997, expenses of $116,162 and total assets of $686,649 at year end.
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