Is it real?
Yes. Never revoked by the IRS. Latest filing on record: FY2025. IRS ruling in Apr 1969.
IRS Pub. 78 · IRS Auto-Revocation List · IRS Business Master File
Where the money goes
78 cents of each dollar spent went to programs.
Form 990 Part IX, line 25, columns B–D. Every line is in By the numbers.
Something off? Claim to add context
Who runs it and what they're paid
50 people listed on the 990; $2.8M paid to officers and key staff.
Mark Bierman’s $744K as Exec Director is at the 94th percentile of top reported officer pay among 749 $10–100M arts & culture nonprofits. Peer set: organizations in the same NTEE major field of work and revenue-size band, compared on each org’s own highest-paid officer/key-employee, from Form 990 Part VII / 990-PF Part VIII. Descriptive placement, not a verdict on whether the pay is appropriate.
Compensation history total reportable pay by year · 8 named individuals · Part VII
| Name | FY2025 | FY2024 | FY2023 | FY2022 | FY2021 | FY2020 |
|---|---|---|---|---|---|---|
| Mark Bierman | $744,010 | $583,952 | $511,137 | — | — | — |
| Chris Flink | — | — | $16,371 | $352,445 | — | $518,635 |
| Robert Semper | $355,605 | $314,320 | $302,784 | $196,504 | $258,806 | $266,741 |
| Phoebe White | — | $344,719 | $281,012 | $228,995 | $220,540 | $211,232 |
| Laura Zander | $328,417 | $286,820 | $305,738 | $231,074 | $239,358 | $251,332 |
| Anne Richardson | $296,384 | $215,636 | $144,334 | — | — | — |
| Blair Winn | $282,663 | $257,640 | $246,443 | $209,571 | $216,006 | $223,648 |
| Julie Nunn | $246,545 | $216,235 | $186,119 | $162,197 | $162,291 | $158,780 |
Total reportable compensation (Form 990 Part VII column D / Schedule J column E) by filing year, matched by name within this organization. The Schedule J base / bonus / deferred breakdown is not parsed into this dataset.
See The Exploratorium executive salaries →Questions the 990 asks
The form asks each of these directly. These are the filed answers.
- Family or business ties among officersPt VI · Ln 2No
- Top official's pay set by an independent reviewPt VI · Ln 15aYes
Programs and updates
Creates hands-on, inquiry-based science and art exhibits and provides professional development to help educators worldwide transform how students learn.
Questions for The Exploratorium
Your first name shows with your question. The Exploratorium answers here, for everyone.
Museum and Visitor Experience
We're an R&D laboratory that experiments with cutting-edge ideas. We create, experiment, test, and build nearly everything at the exploratorium ourselves, always looking for the most interesting and important ideas to pursue, often pushing the limits of what's possible.
Global Collaborations
We learn and share with partners worldwide. By drawing on the exploratorium's broad expertise, global collaborations is able to provide a comprehensive set of creative services from master planning to program development to exhibit fabrication and installation.
Educator Engagement
We're at the forefront of science education. By making science visible, touchable, and accessible to a wide variety of people at the museum, online, and in the classroom, our explore-for-yourself way of learning and teaching influences science education worldwide.
Funders
Who pays for it.
From grant filings on record. Receipts are incomplete: individual donors are never listed.
Grants
Federal money
Plus 1 smaller program.
The auditor reported no findings.
Plus 2 smaller programs.
The auditor reported no findings.
Plus 3 smaller programs.
The auditor reported no findings.
Plus 5 smaller programs.
The auditor reported no findings.
By the numbers
The FY2024 990, line by line.
Download 990
| Line | FY24 | FY23 | FY22 | FY21 | FY20 |
|---|---|---|---|---|---|
| End of yearLn 1g | $88.7M | $77.4M | $74.5M | $82.9M | $65.8M |
| Given inLn 1b | $225K | $1.7M | |||
| SpentLn 1d–1f | $4.0M | $3.4M | $2.3M | $3.6M | $1.8M |
| Line | Start FY24 | End FY24 |
|---|---|---|
| Cash and savingsLn 1–2 | $12.8M | $6.2M |
| InvestmentsLn 11–13 | $84.9M | $99.6M |
| Land, buildings, equipmentLn 10c | $162.3M | $161.4M |
| Total assetsLn 16 | $284.7M | $293.0M |
| LiabilitiesLn 26 | $48.9M | $50.0M |
| Net assetsLn 32 | $235.9M | $243.0M |
| Line | Total | Programs | Management | Fundraising |
|---|---|---|---|---|
| Grants to domestic individualsLn 2 | $5K | $5K | ||
| Grants and assistance to foreign recipientsLn 3 | $4K | $4K | ||
| Pay of current officers, directors and key staffLn 5 | $2.8M | $1.1M | $1.5M | $258K |
| Pay of disqualified personsLn 6 | $30.2M | $24.0M | $4.3M | $1.9M |
| Other employee benefitsLn 9 | $6.0M | $4.9M | $693K | $408K |
| Payroll taxesLn 10 | $2.3M | $2.1M | $122K | $140K |
| Other fees for servicesLn 11g | $11.1M | $8.3M | $2.0M | $716K |
| Advertising and promotionLn 12 | $2.1M | $2.0M | $5K | $60K |
| Office expensesLn 13 | $568K | $502K | $9K | $57K |
| OccupancyLn 16 | $3.3M | $2.5M | $753K | $17K |
| TravelLn 17 | $1.1M | $1.0M | $46K | $1K |
| Conferences, conventions and meetingsLn 19 | $297K | $199K | $85K | $13K |
| Depreciation, depletion and amortizationLn 22 | $4.6M | $4.0M | $639K | $19K |
| Other expenses (24a–d)Ln 24 | $1.6M | $853K | $680K | $23K |
| Total functional expensesLn 25 | $66.0M | $51.5M | $10.9M | $3.6M |
Filing history
| Year | Money in | Money out | In minus out | Net assets | Download |
|---|---|---|---|---|---|
| FY2025 LatestFiled with the IRS May 8, 2026 | $64.0M | $67.8M | −$3.8M | $244.7M | 990 PDF |
| FY2024 ViewingFiled with the IRS May 12, 2025 | $66.6M | $66.0M | $649K | $243.0M | 990 PDF |
| FY2023Filed with the IRS Apr 29, 2024 | $61.0M | $64.8M | −$3.7M | $235.9M | 990 PDF |
| FY2022Filed with the IRS May 8, 2023 | $79.6M | $59.2M | $20.4M | $237.7M | 990 PDF |
| FY2021Filed with the IRS Apr 8, 2022 | $48.0M | $46.9M | $1.1M | $226.2M | 990 PDF |
| FY2020Filed with the IRS Apr 1, 2021 | $48.6M | $53.0M | −$4.4M | $208.8M | 990 PDF |
Schedules filed Part IV
See the full FY2024 990 (6 parts)
Part I · Summary $66,629,029 revenue, 12 lines filed
Part VI · Governance 39 of 39 board members independent, no flags
Part VIII · Statement of revenue $66,629,029 across 11 lines filed
Part IX · Statement of functional expenses $65,980,256 across 14 lines filed
Part X · Balance sheet $293,014,681 assets, 20 lines filed
Part XI · Reconciliation of net assets $242,973,088 net assets at year end
Form 990 e-file (XML) FY2024 from the IRS · Classification, formation year and address from the IRS Business Master File
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