Nonprofit · EIN 22-1710927
MACK FOUNDATION
Tax-exempt · NEW YORK, NY 10128
Address and contacts
- Address (IRS master file)
- 19 E 88TH ST APT 1D, NEW YORK, NY 10128-0558
What it must file and when
IRS records say it files Form 990-PF. Private foundations file every year. Its accounting year ends in December, so each return is due on the 15th day of the 5th month after that.
| Tax year | Year ended | Due | IRS public records |
|---|---|---|---|
| 2025 | December 31, 2025 | May 15, 2026 | 990-PF on file |
| 2024 | December 31, 2024 | May 15, 2025 | 990-PF on file |
| 2023 | December 31, 2023 | May 15, 2024 | 990-PF on file |
IRS record
- EIN
- 22-1710927
- Tax-exempt status
- 501(c)(3): Charitable, religious, educational or scientific organization
- Foundation status
- Private non-operating foundation
- Donations deductible (Pub 78)
- Private foundation, 30% limit
- Exempt since
- 1958
- Accounting year ends
- December
- Files
- Form 990-PF
- Assets (IRS master file)
- $42,913
- Income (IRS master file)
- $26,807
Filing history
| Form | Year ended | Revenue | Expenses | Assets | Return |
|---|---|---|---|---|---|
| 990-PF | December 2025 | – | – | – | IRS |
| 990-PF | December 2024 | – | – | – | IRS |
| 990-PF | December 2023 | $12,330 | $14,246 | $44,427 | IRS |
| 990-PF | December 2022 | – | – | – | IRS |
| 990-PF | December 2021 | – | – | – | IRS |
| 990-PF | December 2020 | – | – | – | IRS |
| 990-PF | December 2018 | – | – | – | IRS |
990-N: the IRS publishes only the latest e-Postcard per organization; earlier years appear here as 990.tax collects the monthly files. 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.
Questions about MACK FOUNDATION
- What is the EIN of MACK FOUNDATION?
- The employer identification number (EIN) of MACK FOUNDATION is 22-1710927.
- Is MACK FOUNDATION tax-exempt?
- Yes. The IRS lists it as tax-exempt under section 501(c)(3) since 1958.
- Are donations to MACK FOUNDATION tax-deductible?
- Yes. It is listed in IRS Publication 78 (Private foundation, 30% limit).
- Which annual return does MACK FOUNDATION file?
- Form 990-PF. Private foundations file every year.
- When is the next return of MACK FOUNDATION due?
- The return for tax year 2026 (the year ending December 31, 2026) is due May 17, 2027. Form 8868 extends it by six months; the 990-N cannot be extended.
- When did MACK FOUNDATION last file with the IRS?
- The latest return in the IRS public files is the 990-PF for the year ended December 2025.
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