Updated 2026
Largest Nonprofits in Maine 2026
A Mainehealth Hcsr is the largest tax-exempt nonprofit in Maine, with $3.7B in annual revenue per IRS Form 990 filings. The top 25 Maine nonprofits hold a combined $4.8B in annual revenue, with an average Efficiency Score of 71/100.
Top 25 Largest Nonprofits in Maine
| # | Nonprofit | Category | Revenue | Grade |
|---|---|---|---|---|
| 1 | A Mainehealth Hcsr | Health | $3.7B | A |
| 2 | Bowdoin College | Education | $355.2M | B |
| 3 | President & Trustees Of Colby College | Education | $287.5M | B |
| 4 | University Of New England | Education | $282.1M | B |
| 5 | President And Trustees Of Bates College | Education | $192.1M | B |
| 6 | Coastal Maine Botanical Gardens Inc | Environment & Animals | $19.4M | C |
What These Numbers Mean
Revenue alone doesn't tell you whether a charity is well-run — a $1B nonprofit can be wasteful and a $5M nonprofit can be highly efficient. The Efficiency Grade above combines four signals: program-expense ratio (50% weight), revenue stability over time (20%), fund reserves in months of operating expenses (20%), and CEO compensation as a share of total expenses (10%).
Maine's nonprofit sector $is mixed: 5 of the top 25 largest organizations earn an A or B Efficiency Grade. Healthcare systems (hospitals, health plans) typically dominate revenue rankings — that's true in most states. Universities and large foundations also frequently appear at the top.
How to Read a Nonprofit Profile
Click any nonprofit above to see its full IRS Form 990 financial breakdown: revenue, expenses, assets, program-expense ratio, CEO compensation, and the four-factor breakdown of our Efficiency Score. The "Where Your Donation Goes" section visualizes how much of every dollar reaches mission work vs. overhead.
For deeper diligence, cross-reference our data with Charity Navigator (program-rating focused), CharityWatch (most rigorous, hand-graded), BBB Wise Giving Alliance (broader accountability standards), and the original ProPublica Nonprofit Explorer for raw Form 990 PDFs.
Frequently Asked Questions
Based on IRS Form 990 revenue filings, A Mainehealth Hcsr is the largest nonprofit in Maine at $3.7B in annual revenue. It receives an Efficiency Grade of A (84/100) based on program-expense ratio, revenue stability, fund reserves, and CEO compensation. The top 25 Maine nonprofits are listed above.
Among the largest Maine nonprofits, A Mainehealth Hcsr earns the highest Efficiency Grade (A, 84/100). Reputability isn't just size — it's how much of every donation reaches programs vs. overhead, fundraising, and executive pay. Our Efficiency Score weights: program ratio (50%), revenue consistency (20%), fund reserves (20%), CEO comp ratio (10%). For broader reputability assessment, cross-reference Charity Navigator and BBB Wise Giving Alliance ratings.
No legitimate charity uses literally 100% of donations on programs — every nonprofit has some overhead (accounting, audits, IRS filings, basic operations). The most efficient Maine nonprofits in our dataset spend 85-95% on programs. Charities claiming "100% to programs" typically mean specific designated funds rather than overall operations. Look for the program-expense ratio in our Efficiency Score — anything above 80% is excellent.
It varies by organization. Federal program-expense ratios in Maine typically range from 60% (lower-rated) to 95% (top-rated). The Better Business Bureau's Wise Giving Alliance considers 65%+ acceptable; Charity Navigator's top tier requires 75%+; CharityWatch's "A" grades require 75-90% depending on category. Our Efficiency Score factor weights program ratio at 50% — pages above with grade A or B mostly hit 75%+.
By total annual revenue from the most recent IRS Form 990 filings (typically prior fiscal year). Form 990 is the public tax return all 501(c)(3) charities must file. We exclude organizations with $0 reported revenue or those still in their first year of filings. Revenue includes contributions, government grants, program service revenue, and investment income.
Each nonprofit name above links to its detailed profile with revenue history, expense breakdown, program ratio, CEO compensation, and our Efficiency Score breakdown. All data is sourced from IRS Form 990 via ProPublica's Nonprofit Explorer API. For raw 990 forms, visit ProPublica or CauseIQ — both publish PDF copies of every nonprofit filing.
Generally yes, with caveats. Larger nonprofits ($100M+ revenue) typically score 5-10 percentage points higher on program-expense ratio because their fundraising and admin costs scale sub-linearly. But the largest nonprofits (especially hospitals and universities) often have higher executive compensation in absolute dollars — which we account for via the CEO-comp ratio factor. Mid-size nonprofits ($10M-$100M) are often the most stretched on overhead.
All revenue, expense, and compensation data comes from IRS Form 990, the federal tax return tax-exempt organizations must file annually. Form 990 data is public record and freely available via ProPublica's Nonprofit Explorer API, CauseIQ, and GuideStar. We cache the most recent filing year for each organization. Fiscal years vary, so reported figures may reflect data 12-24 months old at time of viewing.
Top 25 nonprofits in each state ranked by IRS Form 990 annual revenue (most recent filing year). Efficiency Score combines program-expense ratio (50%), revenue stability (20%), fund reserves (20%), and CEO compensation ratio (10%).