Massachusetts · Nonprofit
ST MARK'S SCHOOL OF SOUTHBOROUGH INC
ST MARK'S SCHOOL OF SOUTHBOROUGH INC (Massachusetts) receives grants from 109 organizations whose IRS filings report $22,322,975 to it, the largest being MANTON FOUNDATION ($6,500,000). 83 of them have funded it in more than one year, and 55% of the money arrives through donor-advised or pass-through sponsors rather than from an institution directly.
- Revenue FY2025
- $37M
- Funders on record
- 109
- Grants received
- $22M
- Net assets
- $197M
What St Mark's School of Southborough Inc does
Mission
Refer to schedule ost. Mark's school educates young people for lives of leadership and service. Founded in 1865 as an intentionally small residential community, the school challenges its students to develop their particular analytic and creative capabilities by both inspiring their academic and spiritual curiosity and kindling their passion for discovery. We value cooperation over self-interest, and we encourage each person to explore his or her place in the larger world beyond our campus.
As stated on its FY2025 Form 990.
Programs
St. Mark's school of southborough, inc. Was founded in 1865 and provides co-educational secondary level education to approximately 375 residential and day students.
$36,216,091 spentof which $6,788,207 as grants$26,645,892 earned by the program100% of program spendingAuxiliary and other income
$0 spent$1,618,429 earned by the program0% of program spending
The 2 programs described on its FY2024 Form 990, listed largest first by expense. Program spending in total: $36,216,091.
The organization over time
Each line starts at 100 in 2017, so what you read is the shape rather than the size: 150 means half as much again as 2017, 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 2020 to 2021, from $218M to $257M (+18%).
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.
13% of ST MARK'S SCHOOL OF SOUTHBOROUGH INC’s revenue is contributions — about as donation-reliant as the typical peer (23% for the typical peer).
Surplus & reserves
Operating surplus or deficit each year, and months of liquidity in hand. 8 of the last 9 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.
Who funds it, year by year
2017 → 2023: the base broadened from 24 funders to 54 funders, grant income rose $434k → $2.9M.
31 of 109 of your funders are donor-advised or pass-through sponsors (tagged DAF) — 55% 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 ST MARK'S SCHOOL OF SOUTHBOROUGH INC’s funders (the co-funder graph). Top 30 of 109 funders by total. 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
ST MARK'S SCHOOL OF SOUTHBOROUGH INC leans on a few funders — its largest provides 29% of grant income and the top three 60%; half comes from just 2 funders.
the vertical line marks half of all grant income — 2 funders to its left
55% 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 ST MARK'S SCHOOL OF SOUTHBOROUGH INC.
Largest funder’s share by year: 2017 32% · 2018 25% · 2019 23% · 2020 59% · 2021 15% · 2022 23% · 2023 34% — broadly stable.
“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
49% of ST MARK'S SCHOOL OF SOUTHBOROUGH INC's funders are still giving 3 years after their first grant; 76% 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
55% of ST MARK'S SCHOOL OF SOUTHBOROUGH INC's grant income arrives through donor-advised or pass-through sponsors, whose addresses record where the money is held rather than where the donor is. Of the $10M that is directly attributable, 86% of it comes from funders outside Massachusetts, across 22 states.
In-state vs out-of-state, by year
Funder states come from each funder’s own filing. $12M arriving through sponsors registered in 19 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
ST MARK'S SCHOOL OF SOUTHBOROUGH INC's revenue grew 50% between 2017 and 2025.
this organization peer median middle 50% of peers· 3,758 education nonprofits $10M–$100M, FY2025
Organizations like ST MARK'S SCHOOL OF SOUTHBOROUGH INC
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
76% of spending goes to programs.
Governance
Footprint & structure
Files a return copy in 3 states
Part of a family of 1 related entity
- Sms Investments Holdings LP · partnership
Screen this organization
A dated, signed PDF of the compliance screen for ST MARK'S SCHOOL OF SOUTHBOROUGH INC: 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 ST MARK'S SCHOOL OF SOUTHBOROUGH INC?
- ST MARK'S SCHOOL OF SOUTHBOROUGH INC (Massachusetts) receives grants from 109 organizations whose IRS filings report $22,322,975 to it, the largest being MANTON FOUNDATION ($6,500,000). 83 of them have funded it in more than one year, and 55% of the money arrives through donor-advised or pass-through sponsors rather than from an institution directly.
- How many funders does ST MARK'S SCHOOL OF SOUTHBOROUGH INC have?
- IRS filings report 109 organizations giving $22,322,975 in grants to ST MARK'S SCHOOL OF SOUTHBOROUGH INC, 83 of which have funded it in more than one year.
- Who is the largest funder of ST MARK'S SCHOOL OF SOUTHBOROUGH INC?
- MANTON FOUNDATION is the largest funder on record, with $6,500,000 in grants. The full list of funders is on this page.
- How can an organization like ST MARK'S SCHOOL OF SOUTHBOROUGH INC 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 St Mark's School of Southborough →
These figures are read directly from IRS Form 990 / 990-PF e-file XML: this organization’s own return for FY2025 (financials across 2017–2025), and the filings of 109 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