· Private foundation
Riverhead Building Supply Charitable Foundation Inc
Its FY2025 filing reports that it funds preselected organizations and did not take unsolicited requests; check the foundation's own site before ruling it out.
What you funded, over time
Every grant clustered by its grantee’s IRS cause code (NTEE), by year — across FY2017–2025.
Where the money goes
Your grants by size, and where they go.
By grant size · FY2025
- Under $10k3 grants · $10k
- $10k–50k5 grants · $85k
- $50k–250k2 grants · $240k
| Recipient | Amount |
|---|---|
| HABITAT FOR HUMANITY OF EASTERN CT INC | $150,000 |
| RIVERHEAD VOLUNTEER AMBULANCE CORPS INC | $90,000 |
| CYSTIC FIBROSIS FOUNDATION | $30,000 |
| WARRIOR RANCH FOUNDATION | $25,000 |
| GLORIA GEMMA BREAST CANCER | $10,350 |
| Individual grant recipient | $10,000 |
| INSPIRATIONAL TRIATHLON RACING | $10,000 |
| EAST END ARTS & HUMANITIES COUNCIL | $5,000 |
| IN JORDAN'S HONOR LTD | $2,500 |
| TIMOTHY HILL CHILDREN'S RANCH INC | $2,500 |
Do your dollars go where the need is?
Each grant placed by the hardship in its grantee’s ZIP, then read against the area’s typical level.
Your human-services grants (FY17–25, $308k) land where the poverty rate runs at 7%, against an area that typically sits at 5%. 100% of those dollars go to grantees based in above-average-need neighborhoods. Most of your grants land in higher-need ZIPs.
Matched: human-services grants are those whose grantee’s IRS cause code is Human Services. Placed by people below the poverty linein the grantee’s ZIP, averaged from the tracts in that ZIP; grantee ZIP can differ from where services are delivered.
US grants placed by each grantee’s ZIP, which can differ from where services are actually delivered. Need from public data — U.S. Census/ACS, CDC PLACES, Eviction Lab, USDA — shown as context about the area, never attributed to your giving.
Where the work is directed
The same grants, placed two ways — where each recipient sits, and where its stated purpose earmarks the money.
About 26% of Riverhead Building Supply Charitable Foundation Inc’s grant dollars are earmarked, by their stated purpose, for a different county than the recipient’s own address — money that lands at a nonprofit in one place but is meant to do its work in another. Read by recipient address, 80% of the giving stays in NY; read by stated purpose it is 67% — less of the work is directed home than the recipients' locations suggest.
Recipient view: each grant at its grantee’s ZIP, mapped to a county. Directed view: each grant at the county its stated purpose names, falling back to the recipient’s county when the purpose names no place; US grants only. A county shows only if it carries the top 95% of that view’s dollars. Purposes are read from the foundation’s own 990 grant descriptions.
Who you back again
Which organizations you funded more than once, and which you funded a single time. Each grantee is matched to its own filings.
And the relationships you keep tend to grow: grantees you re-up on have seen median revenue of +41% since the first grant, against 0% for the ones you funded once.
14 repeat relationships — 8 still active in FY2025, 6 since wound down; 2 grantees were first funded in FY2025 (too recent to call).
How the two cohorts compare
Organizations
Total granted
Median revenue growth · since first grant
Still filing today
New vs renewed · share of each year
In FY2025, 66% of grant dollars renewed an existing relationship; $115k went to new ones.
Where new relationships form · theme of each grantee’s first grant
First-time = a grantee’s first year in your filing window; renewed = funded in an earlier year too. As a portfolio matures the renewed share naturally climbs — once funded, an org stays “renewable” — so the signal is the years that buck it (a new-grantee intake wave). The earliest year is left-censored: relationships that predate the data read as “new.” Theme is the grantee’s IRS cause.
Backed again, and grew
- THTIMOTHY HILL CHILDREN'S RANCH INC7× · 2017–2025 · $285k · revenue +112%
- HFHABITAT FOR HUMANITY OF LONG ISLAND INC3× · 2020–2022 · $180k · revenue +41%
- CFCYSTIC FIBROSIS FOUNDATION4× · 2022–2025 · $90k · revenue +43%
Funded once
- PHPBMC HEALTH FOUNDATIONone grant, 2017 · $500k
- HFHABITAT FOR HUMANITYone grant, 2017 · $104k
- SCSUFFOLK COUNTY COUNCIL BOY SCOUTS OF AMERICAgraduatedone grant, 2020 · $56k · revenue +64%
Repeat = funded in two or more distinct years; growth and survival are read from each grantee’s own subsequent IRS filings.
The map has a center of gravity: the average direction from the rest of the sector toward the organizations the foundation funds — the shape of its giving. Scoring every nonprofit along that direction surfaces the ones that look most like the portfolio. These are the closest matchesthat aren’t grantees — a resemblance in what they say they do, not a recommendation.
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For reference, the grantee most central to the portfolio’s shape is The Southampton Hospital Foundation Inc and the most unlike its peers is Cystic Fibrosis Foundation. Resemblance is measured on each organization’s own IRS 990 mission text; it reflects how work is described, not its quality or impact.
For each theme you fund, this compares how the sector’s money is shifting with how your own giving is shifting.
Sector change and giving change are each shown relative to their own range, growing (right) or shrinking (left); both normalized, so inflation isn’t mistaken for growth.
Your grantees are a median of 38 years old; the field is 16. You back the established end — and your money leans older still.
The field is 20% startups (under 5 years old) — 4% of your grantees by number, and just 2% of your money.
The orgs you fund almost never close — 7% lost their exemption, against 10% of the field you don’t fund.
Age = years since IRS exemption (a founding proxy). “Closed” = auto-revocation for 3 years of non-filing — a floor on closure, not proof, and bigger established orgs lapse least. Association, not causation.
26 grantees tracked through their own filings, 2017–2025.
Each one resolved to its own IRS returns and tracked year by year — your grant beside their revenue from every source. Association, dated; never a causal claim.
Counted here: distinct organizations you funded across 2017–2025, not grant rows in a single year — so this will not match the grant count on the cover. 26 of the 34 grantees resolved in that span have returns of their own we could reconcile; the rest are funded organizations whose filings we could not track year by year.
Where your money sits — by cause, then by grantee
Each org by its size and your share of it — top-left is where you’re load-bearing
Go grantee by grantee — a decade per org, and how each moved after you funded them
A decade per grantee — revenue shaded, your grants as bars, all rows on one timeline.
- Who funds TIMOTHY HILL CHILDREN'S RANCH INC ↗
- Who funds PECONIC HOCKEY FOUNDATION INC ↗
- Who funds Habitat for Humanity of Eastern Connecticut Inc ↗
- Who funds HABITAT FOR HUMANITY OF LONG ISLAND INC ↗
- Who funds CYSTIC FIBROSIS FOUNDATION ↗
- Who funds RIVERHEAD VOLUNTEER AMBULANCE CORPS INC ↗
- Who funds SUFFOLK COUNTY COUNCIL BOY SCOUTS OF AMERICA ↗
- Who funds ST CHARLES HOSPITAL FOUNDATION ↗
- Who funds LT MICHAEL P MURPHY NAVY SEAL MUSEUM ↗
- Who funds East End Food Institute ↗
- Who funds East End Arts & Humanities Council ↗
- Who funds INSPIRATIONAL TRIATHLON RACING INTERNATIONAL CORP ↗
- Who funds FAMILY COMMUNITY LIFE CENTER INC ↗
- Who funds MONTAUK HISTORICAL SOCIETY ↗
- Who funds Penobscot Bay Medical Center ↗
- Who funds WARRIOR RANCH FOUNDATION INC ↗
- Who funds PADDLERS FOR HUMANITY INC ↗
- Who funds The Neighborhood House of Long Island ↗
- Who funds Retreat Inc ↗
- Who funds LONG ISLAND HOUSING PARTNERSHIP INC ↗
- Who funds HAMPTONS YOUTH CAMPS INC ↗
- Who funds MATTITUCK-LAUREL LIBRARY ↗
- Who funds LONG ISLAND COUNCIL OF CHURCHES INC ↗
- Who funds Andy Foundation ↗
- Who funds THE SOUTHAMPTON HOSPITAL FOUNDATION INC ↗
- Who funds STONY BROOK FOUNDATION INC ↗
The grantmakers whose grantees overlap with yours far more than size alone predicts. Each orbits closer the stronger the alignment; the arcs between them show where they also fund each other. Here it reads as a tightly interlocked camp — most of these funders back each other's grantees too.
Open a dossier: Peoples United Community Foundation · The New York Community Trust · The Bank of America Charitable Foundation Inc · Network for Good · National Philanthropic Trust · Vanguard Charitable Endowment Program · Fidelity Investments Charitable Gift Fund · American Online Giving Foundation Inc · Donor Advised Charitable Giving Inc · Amazonsmile Foundation
Affinity is a Gamma-Poisson posterior co-funding rate, re-centered on the typical rate, so thin evidence shrinks toward no signal. A research starting point: overlap is association, not proof of shared intent.
Government reliance of your grantees
Every dot is one organization Riverhead Building Supply Charitable Foundation Inc funds. Left–right is the share of its income from government; up–down is the share from you. Bigger dots raise more. Filter to federal or a single department — and drag the year to watch it move.
Government income is each org’s traced federal awards (USASpending — grants and contracts) plus state payments (open checkbooks) as a share of its total revenue (IRS Form 990); the self-reported government-grant line (990 line 1e) is carried for cross-check: a grantee that reports government grants we could not trace to a source is left off the chart rather than shown as receiving none. An association, not a claim that your grant caused the public funding. Coverage is precision-first — a floor, not a census; state records exist for 9 states, so a grantee outside them shows no state figure (dimmed) rather than a false zero. Federal award amounts are obligations, which can span years, so a single-year share is indicative. 990 filings lag 12–24 months.
Warm introductions · Powered by PlinthPlus
How do I get to Riverhead Building Supply Charitable Foundation Inc?
Find your warmest path to Riverhead Building Supply Charitable Foundation Inc through trustees and officers whose names appear on both boards. Search for your organization and Plinth traces the shortest route it can evidence.
Each link is a name appearing on two organizations’ public IRS 990 filings, matched on that name and, where the filings support it, on location. A same-state match has geographic support, which is a second matching feature rather than confirmation that the two are one person; a cross-state one is the likeliest to be two people who share a name. Every hop shows its tier, low-confidence and distant paths are held back rather than guessed, and it is worth confirming the person before you use the introduction.