Massachusetts · Nonprofit
STONELEIGH-BURNHAM SCHOOL
STONELEIGH-BURNHAM SCHOOL (Massachusetts) receives grants from 28 organizations whose IRS filings report $2,034,901 to it, the largest being Tarbell Family Foundation ($803,217). 20 of them have funded it in more than one year.
- Revenue FY2025
- $11M
- Funders on record
- 28
- Grants received
- $2.0M
- Net assets
- $4.2M
What Stoneleigh-Burnham School does
Mission
Stoneleigh-Burnham School is an academic community that fosters an international perspective. We inspire girls to pursue meaningful lives based on honor, respect, and intellectual curiosity. Each student is challenged to discover her best self and graduate with confident to think independently and act ethically, secure in the knowledge that her voice will be heard.
As stated on its FY2025 Form 990.
Program
Stoneleigh-Burnham School is an academic community that fosters an international perspective. Stoneleigh-Burnham School offers the international baccalaureate (ib) diploma. Each student is challenged to discover her best self and graduate with confidence to think independently and act ethically, secure in the knowledge that her voice will be heard.
$6,073,459 spentof which $1,523,422 as grants$5,182,062 earned by the program100% of program spending
The program described on its FY2024 Form 990. Program spending in total: $6,073,459.
The organization over time
Each line starts at 100 in 2019, so what you read is the shape rather than the size: 150 means half as much again as 2019, 50 means half. The number beside each label in the key is where it ended. The shaded band is where the middle 50% of its peers' revenue would sit, given their growth.
Balance sheet
Total assets and total liabilities at each year end, in dollars. The largest one-year move in total assets was 2024 to 2025, from $8.3M to $11M (+32%).
How it's funded, over time
Each bar is one year's revenue split into where it came from, and every bar is the same height — these are shares, not amounts, so a year that raised twice as much looks the same size. Hover a bar for the split.
Government-grant reliance: 2021 9% · 2022 10%. Grants only. Government contracts and fees sit inside program revenue.
53% of STONELEIGH-BURNHAM SCHOOL’s revenue is contributions — more donation-reliant than the typical peer (23% for the typical peer).
Surplus & reserves
Operating surplus or deficit each year, and months of liquidity in hand. 4 of the last 7 reported years ran a deficit.
reserve
Leadership and staff
The officers, directors, trustees and key employees listed on each return. Joined and no longer listed compare each filing with the year before, matching people by surname and first initial; a year after a gap, or a roster under three people, has no comparison.
Board chair
Barbara Mayo Llewellyn
Chair
As listed on its FY2025 Form 990.
Who funds it, year by year
2017 → 2023: the base broadened from 6 funders to 11 funders, grant income rose $83k → $259k.
9 of 28 of your funders are donor-advised or pass-through sponsors (tagged DAF) — 36% of grant dollars received. That money is really individual donors directing a sponsor; the institutions to cultivate are the non-DAF funders.
From the IRS filings of STONELEIGH-BURNHAM SCHOOL’s funders (the co-funder graph). Association, not causation. Trends are read to FY2023, the last fiscal year that has finished arriving. FY2024–FY2026 are still being filed and are shown unshaded; they do not move any figure on this page.
How concentrated its funding is
STONELEIGH-BURNHAM SCHOOL leans on a few funders — its largest provides 39% of grant income and the top three 63%; half comes from just 2 funders.
the vertical line marks half of all grant income — 2 funders to its left
36% of the income these shares are computed over arrives through pass-through sponsors or from payers whose filings do not say what kind of payment it is. Concentration is still measured over all of it, because the money is real; what it does not support is a claim about how many institutions have chosen to fund STONELEIGH-BURNHAM SCHOOL.
Largest funder’s share by year: 2017 85% · 2018 81% · 2019 48% · 2020 45% · 2021 23% · 2022 44% · 2023 50% — diversifying over time.
“Effective funders” = inverse Herfindahl index (1 / Σ shareᵢ²) — the number of equal-sized funders that would give the same concentration. Trends are read to FY2023, the last fiscal year that has finished arriving. FY2024–FY2026 are still being filed and are shown unshaded; they do not move any figure on this page.
How long its funders stay
44% of STONELEIGH-BURNHAM SCHOOL's funders are still giving 3 years after their first grant; 71% give in more than one year at all.
Share of funders still giving k years after their first recorded grant, pooled across every acquisition cohort. A funder counts as retained in a year only if it made a grant that year. Measured to FY2023, the last fiscal year that has finished arriving — a funder cannot be counted as lapsed in a year most filers have not reached.
Where its funders are
STONELEIGH-BURNHAM SCHOOL draws 97% of its grant income from funders outside Massachusetts, across 10 states in all.
In-state vs out-of-state, by year
Funder states come from each funder’s own filing. $734k arriving through sponsors registered in 7 states is excluded from the map and the split above: a sponsor holds money on a donor’s behalf, so its registered address would place those dollars somewhere no donor need ever have been. Trends are read to FY2023, the last fiscal year that has finished arriving. FY2024–FY2026 are still being filed and are shown unshaded; they do not move any figure on this page.
Against its field
STONELEIGH-BURNHAM SCHOOL runs a healthier operating margin than three-quarters of the 3,758 education nonprofits its size.
this organization peer median middle 50% of peers· 3,758 education nonprofits $10M–$100M, FY2025
Organizations like STONELEIGH-BURNHAM SCHOOL
Organizations whose mission and program text most resemble this one, by semantic similarity over every organization in the US filings — the closest peers, and often the clearest route to shared or prospective funders.
In Massachusetts
Nationally
Read directly from this organization’s own Form 990, as neutral context.
Where the money goes
70% of spending goes to programs.
Governance
Footprint & structure
Files a return copy in 1 state
Screen this organization
A dated, signed PDF of the compliance screen for STONELEIGH-BURNHAM SCHOOL: IRS status (Business Master File, Publication 78, auto-revocation), the OFAC sanctions lists, the Internal Revenue Bulletin, and California registration, with the Rev. Proc. 2018-32 §8.01 reliance elements stated element by element. Generated from the current files at the moment you download it.
Screens are triage, not determinations; a source that cannot be read reports not screened, never clear. Screen this nonprofit · How the screen works · on the API as GET /api/screening/{ein}?format=pdf
Questions and answers
- Who funds STONELEIGH-BURNHAM SCHOOL?
- STONELEIGH-BURNHAM SCHOOL (Massachusetts) receives grants from 28 organizations whose IRS filings report $2,034,901 to it, the largest being Tarbell Family Foundation ($803,217). 20 of them have funded it in more than one year.
- How many funders does STONELEIGH-BURNHAM SCHOOL have?
- IRS filings report 28 organizations giving $2,034,901 in grants to STONELEIGH-BURNHAM SCHOOL, 20 of which have funded it in more than one year.
- Who is the largest funder of STONELEIGH-BURNHAM SCHOOL?
- Tarbell Family Foundation is the largest funder on record, with $803,217 in grants. The full list of funders is on this page.
- How can an organization like STONELEIGH-BURNHAM SCHOOL find more funders?
- Start with the funders already giving here, then look at the foundations that back similar organizations in Massachusetts. The funding by cause and by state pages list the largest funders for a given area and how to approach them.
Play a game about who funds Stoneleigh-Burnham School →
These figures are read directly from IRS Form 990 / 990-PF e-file XML: this organization’s own return for FY2025 (financials across 2019–2025), and the filings of 28 funders that report grants to it. “On record” means captured in the filings we have parsed — a funder that does not e-file, or whose grant detail is not itemized, will not appear. Filings run roughly 12–24 months behind. Trends on this page end at FY2023, the last fiscal year that has finished arriving; later years are shown and marked, and move no figure. Data on this page was exported October 14, 2026. What this page cannot tell you · view filing