Is it real?
Yes. Never revoked by the IRS. Latest filing on record: FY2025. IRS ruling in May 2014.
IRS Pub. 78 · IRS Auto-Revocation List · IRS Business Master File
Where the money goes
91 cents of each dollar spent went to programs.
Form 990 Part IX, line 25, columns B–D. Every line is in By the numbers.
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Who runs it and what they're paid
14 people listed on the 990; $1.1M paid to officers and key staff.
Samuel Vandervelde’s $268K as Head of School is at the 57th percentile of top reported officer pay among 3683 $10–100M education 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 |
|---|---|---|---|---|---|---|
| Samuel Vandervelde | $267,945 | $250,853 | $244,080 | $236,178 | — | — |
| Kathy Lin | $253,120 | $234,360 | $219,974 | $210,846 | $199,063 | $189,051 |
| Zachary Sifuentes | $242,597 | $223,153 | $210,489 | $201,981 | $191,331 | $183,316 |
| Samuel K Vandervelde | — | — | — | — | $225,899 | $219,773 |
| Jason Horowitz | $124,168 | $114,878 | $106,245 | $105,614 | $102,092 | $101,098 |
| Susan Durst | $122,671 | $111,833 | $103,917 | $103,917 | — | — |
| Connie You | $114,657 | $100,470 | — | — | — | — |
| Michael Yetman | $111,605 | — | — | — | — | — |
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.
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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
Educates children who love math, reasoning, and communication with a liberal arts approach.
Questions for Proof School
Your first name shows with your question. Proof School answers here, for everyone.
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Proof school delivered a comprehensive middle and high school curriculum to a total of 113 students in grades 6-12 during the 2023-24 academic year. School was in session for 172 days; the school held info sessions, ran admissions, and graduated 13 students.
Funders
Who pays for it.
From grant filings on record. Receipts are incomplete: individual donors are never listed.
Grants
By the numbers
The FY2024 990, line by line.
Download 990
| Line | Start FY24 | End FY24 |
|---|---|---|
| Cash and savingsLn 1–2 | $1.4M | $2.3M |
| InvestmentsLn 11–13 | $4.3M | $4.6M |
| Land, buildings, equipmentLn 10c | $1.5M | $1.3M |
| Total assetsLn 16 | $10.1M | $11.6M |
| LiabilitiesLn 26 | $4.9M | $5.6M |
| Net assetsLn 32 | $5.2M | $6.0M |
| Line | Total | Programs | Management | Fundraising |
|---|---|---|---|---|
| Grants to domestic individualsLn 2 | $1.0M | $1.0M | ||
| Pay of current officers, directors and key staffLn 5 | $828K | $828K | ||
| Other salaries and wagesLn 7 | $1.9M | $1.7M | $184K | |
| Pension plan contributionsLn 8 | $130K | $121K | $9K | |
| Other employee benefitsLn 9 | $253K | $234K | $18K | |
| Payroll taxesLn 10 | $181K | $167K | $14K | |
| Legal feesLn 11b | $1K | $1K | ||
| Accounting feesLn 11c | $9K | $7K | $2K | |
| Other fees for servicesLn 11g | $10K | $10K | ||
| Office expensesLn 13 | $19K | $13K | $5K | |
| Information technologyLn 14 | $25K | $20K | $5K | |
| OccupancyLn 16 | $928K | $720K | $208K | |
| Depreciation, depletion and amortizationLn 22 | $282K | $220K | $62K | |
| InsuranceLn 23 | $36K | $28K | $8K | |
| Other expenses (24a–d)Ln 24 | $309K | $300K | $9K | |
| All other expensesLn 24e | $17K | $17K | ||
| Total functional expensesLn 25 | $5.9M | $5.4M | $518K | $26K |
Filing history
| Year | Money in | Money out | In minus out | Net assets | Download |
|---|---|---|---|---|---|
| FY2025 Latest | $11.2M | $6.7M | $4.5M | $10.5M | 990 PDF |
| FY2024 Viewing | $6.7M | $5.9M | $768K | $6.0M | 990 PDF |
| FY2023 | $6.5M | $5.8M | $711K | $5.2M | 990 PDF |
| FY2022 | $6.4M | $5.9M | $492K | $4.5M | 990 PDF |
| FY2021 | $6.2M | $5.3M | $876K | $4.0M | 990 PDF |
| FY2020 | $5.3M | $4.9M | $375K | $3.1M | 990 PDF |
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Schedules filed Part IV
See the full FY2024 990 (6 parts)
Part I · Summary $6,704,431 revenue, 12 lines filed
Part VI · Governance 7 of 8 board members independent, no flags
Part VIII · Statement of revenue $6,704,431 across 8 lines filed
Part IX · Statement of functional expenses $5,936,734 across 16 lines filed
Part X · Balance sheet $11,550,096 assets, 14 lines filed
Part XI · Reconciliation of net assets $5,950,901 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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