What Is a Foundation and How Are They Classified
A foundation is a nonprofit organization that pools capital to make grants or investments for charitable, educational, or scientific purposes. The two primary classifications are private foundations, typically funded by a single family or corporation, and public charities, which raise funds from the general public. In the United States, the Internal Revenue Service distinguishes them under sections 501(c)(3) and 4947, with private foundations often subject to stricter payout and excise tax rules. The Foundation Center, now part of Candid, maintains the most comprehensive global database of grantmaking institutions.
Foundations can also be categorized by their asset size, grantmaking focus, and geographic scope. Community foundations aggregate donations from many donors to serve a specific region, while operating foundations run their own programs rather than making outside grants. Corporate foundations are created and funded by a for-profit company, and grantmaking public charities, such as large hospitals or universities, distribute funds based on a broad public mission. Understanding these categories helps donors and researchers quickly identify the right type of foundation for a specific cause.
Largest Foundations by Total Assets and Annual Grants
Top 10 Foundations by Assets
The Bill & Melinda Gates Foundation leads globally with total assets exceeding $50 billion as of the most recent IRS Form 990 filings, followed by the Ford Foundation and the Chan Zuckerberg Initiative. The Lilly Endowment, the largest private foundation in the United States by assets, focuses on education, religion, and community development in Indiana. The Wellcome Trust, a British-based global charitable foundation, manages over $30 billion to support biomedical research and public health. The Open Society Foundations, founded by George Soros, operate across more than 120 countries with a focus on justice, democratic governance, and public health.
The Bezos Earth Fund, established by Jeff Bezos, has committed $10 billion to combat climate change, while the Bloomberg Philanthropies and the Rockefeller Foundation consistently rank among the top ten by annual giving volume. The Knight Foundation focuses on journalism, arts, and community vitality in U.S. cities, and the David and Lucile Packard Foundation supports conservation, science, and reproductive health. These organizations collectively distribute tens of billions of dollars annually, shaping sectors from higher education to global health.
How Asset Size Compares to Grantmaking Output
Total assets do not always equal annual grant spending, as some large foundations hold significant long-term investments while others spend down their endowments. The Gates Foundation typically distributes over $5 billion per year, while the Ford Foundation has committed to spending down a portion of its endowment over a decade to increase its annual impact. The SEC requires large private foundations to file Form 990-PF annually, which details their assets, income, and qualifying distributions for public access.
How to Find and Verify a Foundation
Researchers can use free databases such as the Candid GuideStar platform, the Foundation Center's online search tools, and the IRS Tax Exempt Organization Search to locate a foundation's mission, grants, and financials. Most U.S. private foundations with total assets over $250,000 must file Form 990-PF, which is publicly available and includes details on executive compensation, grants paid, and investment income. Forbes and other outlets regularly publish rankings of the largest foundations based on these filings.
When evaluating a foundation, check its IRS determination letter, annual reports, and grantee lists to confirm its active status and focus areas. The SEC's EDGAR database also contains filings for foundations that operate related for-profit entities or make large investments in public companies. For international foundations, organizations like the European Foundation Centre and national charity regulators provide searchable registries with financial and governance data.