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EIN52-1121163

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National Aquarium Inc.

Updated October 30, 2026. Based on Internal Revenue Service records. Published by Humblebee.

Exempt under
501(c)(3)[1]
IRS ruling date
April 1979[2]
Publication 78 data
Listed (PC)[3]
Total revenue, period ending Dec 2025
$54,351,794[4]

National Aquarium Inc. is located in Baltimore, Maryland, in IRS records[5]. The IRS lists it as exempt under section 501(c)(3)[1] and lists total revenue of $54,351,794 for the tax period ending December 2025[4].

IRS status

The IRS lists National Aquarium Inc. as exempt under section 501(c)(3), classification: Charitable Organization[1]. Its IRS foundation code is 16, described as an organization that normally receives no more than one-third of its support from gross investment income and unrelated business income and at the same time more than one-third of its support from contributions, fees, and gross receipts related to exempt purposes 509(a)(2)[6]. It appears in Publication 78 with status code PC, a public charity[3]. The IRS ruling date is April 1979[2].

Item IRS record
EIN[5] 52-1121163
Location in IRS records[5] Baltimore, Maryland
Exempt under[1] Section 501(c)(3)
IRS classification[1] Charitable Organization
Ruling date[2] April 1979
Foundation code[6] 16: Organization that normally receives no more than one-third of its support from gross investment income and unrelated business income and at the same time more than one-third of its support from contributions, fees, and gross receipts related to exempt purposes 509(a)(2)
Deductibility code[7] 1: Contributions are deductible
Publication 78 data[3] Listed, status PC
NTEE code[8] D500: Animal-Related, Zoo, Zoological Society
Filing requirement[9] 990 (all other) or 990EZ return
Fiscal year ends[10] December
Latest e-filed return[11] Form 990, tax period ending December 2025

Finances as reported to the IRS

On its Form 990 for the tax period ending December 2023, the organization reported total revenue of $55,641,673[12]. That included contributions, gifts and grants of $16,175,128 and program service revenue of $34,859,573[13]. Total expenses were $54,083,927 and net assets were $64,431,700 for that period[12]. Total revenue was $60,590,294 on its Form 990 for the tax period ending December 2021[14] and $54,816,849 for the tax period ending December 2022[15].

IRS master file, newer period. For the most recent return in the IRS master file, for the tax period ending December 2025, the IRS lists total revenue of $54,351,794 and total assets of $92,109,787.[4]

December 2021: total revenue $60.6M$60.6MDecember 2021: total expenses $47.7M$47.7MDec 2021December 2022: total revenue $54.8M$54.8MDecember 2022: total expenses $51.4M$51.4MDec 2022December 2023: total revenue $55.6M$55.6MDecember 2023: total expenses $54.1M$54.1MDec 2023
  • Total revenue
  • Total expenses
Amounts as reported on each return, rounded in the chart. Exact figures are in the table below[12].
Tax period ending Form Total revenue Total expenses Net assets at year end
December 2021[14]Form 990$60,590,294$47,737,626$57,438,961
December 2022[15]Form 990$54,816,849$51,432,748$63,164,743
December 2023[12]Form 990$55,641,673$54,083,927$64,431,700

Totals as reported on each return. The IRS publishes these extracts one to two years after filing.

Balance sheet, tax period ending December 2023

Line Amount
Total assets[16] $108,867,004
Total liabilities[16] $44,435,304
Net assets or fund balances[16] $64,431,700

Employees. National Aquarium Inc. reported 442 employees on Form W-3 for calendar year ending with or within the tax period ending December 2023 (Form 990, Part V, line 2a).[17]

Compensation over $100,000. On the Form 990 for the tax period ending December 2023, National Aquarium Inc. reported 19 individuals who received more than $100,000 of reportable compensation from the organization (Part VII, line 2).[18]

Form 990 checklist. In the Form 990 checklist (Part IV) for the tax period ending December 2023, National Aquarium Inc. answered yes to: it engaged in lobbying activities; it reported professional fundraising services.[19]

Questions people ask

What is the EIN of National Aquarium Inc.?
The employer identification number is 52-1121163[5].
Is National Aquarium Inc. a 501(c)(3) nonprofit?
The IRS lists it as exempt under section 501(c)(3), classification: Charitable Organization[1].
Are contributions to National Aquarium Inc. tax-deductible?
IRS deductibility code 1 reads: Contributions are deductible[7]. It appears in Publication 78 with status code PC[3].
Where is National Aquarium Inc. located?
The IRS master file lists it in Baltimore, Maryland[5].
What revenue did National Aquarium Inc. report?
On its Form 990 for the tax period ending December 2023, it reported total revenue of $55,641,673[12]. The IRS master file lists $54,351,794 for the tax period ending December 2025[4].

Facts and sources

  1. The IRS lists National Aquarium Inc. as exempt under section 501(c)(3) of the Internal Revenue Code, classification: Charitable Organization. IRS EO Business Master File
  2. The ruling date in the IRS master file (the month and year of the IRS letter recognizing the exemption) is April 1979. IRS EO Business Master File
  3. National Aquarium Inc. (EIN 52-1121163) appears in the IRS Publication 78 data, the list of organizations eligible to receive tax-deductible charitable contributions, with status code PC (A public charity, deductibility limitation 50% (60% for cash contributions)). IRS Tax Exempt Organization Search data
  4. For the most recent return in the IRS master file, for the tax period ending December 2025, the IRS lists total revenue of $54,351,794 and total assets of $92,109,787. IRS EO Business Master File
  5. The IRS Exempt Organizations Business Master File lists National Aquarium Inc. with employer identification number (EIN) 52-1121163, located in Baltimore, Maryland. IRS EO Business Master File
  6. IRS foundation code 16 for National Aquarium Inc.: Organization that normally receives no more than one-third of its support from gross investment income and unrelated business income and at the same time more than one-third of its support from contributions, fees, and gross receipts related to... IRS EO Business Master File
  7. IRS deductibility code 1 for National Aquarium Inc.: Contributions are deductible. IRS EO Business Master File
  8. The IRS master file assigns National Aquarium Inc. the National Taxonomy of Exempt Entities (NTEE) code D500: Animal-Related, Zoo, Zoological Society. IRS EO Business Master File
  9. IRS filing requirement code 01 for National Aquarium Inc.: 990 (all other) or 990EZ return. IRS EO Business Master File
  10. National Aquarium Inc.'s accounting period (fiscal year) ends in December, according to the IRS master file. IRS EO Business Master File
  11. The IRS Form 990 series e-file data released in 2026 includes a Form 990 from National Aquarium Inc. for the tax period ending December 2025. IRS Form 990 e-file data
  12. On its Form 990 for the tax period ending December 2023, National Aquarium Inc. reported total revenue $55,641,673, total expenses $54,083,927, net assets or fund balances at year end $64,431,700. IRS SOI Form 990 extracts
  13. Revenue lines on the Form 990 for the tax period ending December 2023: contributions, gifts and grants $16,175,128 (Part VIII, line 1h); program service revenue $34,859,573 (Part VIII, line 2g); investment income $1,060,358 (Part VIII, line 3); total revenue $55,641,673 (Part VIII, line 12). IRS SOI Form 990 extracts
  14. On its Form 990 for the tax period ending December 2021, National Aquarium Inc. reported total revenue $60,590,294, total expenses $47,737,626, net assets or fund balances at year end $57,438,961. IRS SOI Form 990 extracts
  15. On its Form 990 for the tax period ending December 2022, National Aquarium Inc. reported total revenue $54,816,849, total expenses $51,432,748, net assets or fund balances at year end $63,164,743. IRS SOI Form 990 extracts
  16. Balance sheet at the end of the tax period ending December 2023 (Form 990, Part X): total assets $108,867,004, total liabilities $44,435,304, net assets or fund balances $64,431,700. IRS SOI Form 990 extracts
  17. National Aquarium Inc. reported 442 employees on Form W-3 for calendar year ending with or within the tax period ending December 2023 (Form 990, Part V, line 2a). IRS SOI Form 990 extracts
  18. On the Form 990 for the tax period ending December 2023, National Aquarium Inc. reported 19 individuals who received more than $100,000 of reportable compensation from the organization (Part VII, line 2). IRS SOI Form 990 extracts
  19. In the Form 990 checklist (Part IV) for the tax period ending December 2023, National Aquarium Inc. answered yes to: it engaged in lobbying activities; it reported professional fundraising services. IRS SOI Form 990 extracts

All figures are as the organization reported them to the IRS for the stated tax period. Say the tax period with every figure. Finance figures come from the IRS SOI annual extracts, which lag filing by one to two years. The IRS master file can list a newer period: keep the two apart and name each period. To see an organization's own filings, use the IRS Tax Exempt Organization Search.