Key Takeaways
Lilly Endowment's newest IRS Form 990-PF reports an endowment of $105.9 billion as of the end of 2025, the first US foundation ever to cross $100 billion on a tax filing.
The endowment is built almost entirely on Eli Lilly stock, which has surged on demand for the company's weight loss drugs Zepbound and Mounjaro.
Federal law requires private foundations to pay out about 5% of assets each year, which will soon put Lilly Endowment's required grantmaking near $5 billion annually, more than double the $2.28 billion it disbursed in 2024.
Weight loss drugs have produced a philanthropic first. Lilly Endowment, the Indianapolis foundation built on Eli Lilly and Company stock, reported an endowment of $105,894,116,636 as of the end of 2025 in its latest IRS Form 990-PF, making it the first US foundation to cross the $100 billion line on a federal tax filing. Michael Kavate, who covers philanthropy and billionaire donors, surfaced the number from the newest batch of filings on ProPublica's Nonprofit Explorer. "Weight-loss drugs have created America's first $100 billion foundation endowment," Kavate wrote.
The trajectory is steep even by bull market standards. The foundation's prior filing showed $79.9 billion in total assets at the end of 2024, up from $62.2 billion a year before that. Bloomberg reported the endowment first touched $100 billion in market value in late 2025 as Eli Lilly shares climbed on demand for Zepbound and Mounjaro. The stock has kept rising since, which means even the new filing likely understates what the foundation holds today.
Here is why the number matters beyond bragging rights. Federal law requires private foundations to distribute about 5% of assets annually, so a $105.9 billion endowment will soon obligate Lilly Endowment to grant roughly $5 billion a year. It disbursed $2.28 billion in 2024. That gap between what the law will require and what the foundation has historically moved is the story to watch, and it lands in the middle of a live debate over whether the 5% payout floor has quietly become a ceiling, in a week when Warren Buffett redirected nearly $6 billion of his own giving.
People Also Ask
What is the largest foundation endowment in the United States?
Lilly Endowment, at $105.9 billion as of the end of 2025 per its latest IRS filing. It is the first US foundation to report an endowment above $100 billion.
Why is the Lilly Endowment growing so fast?
Its endowment is overwhelmingly Eli Lilly and Company stock, which has surged on demand for the company's weight loss and diabetes drugs, including Zepbound and Mounjaro.
How much does the Lilly Endowment have to give away each year?
Private foundations must distribute about 5% of assets annually under federal law. At its new size, Lilly Endowment's required payout will approach $5 billion a year, versus the $2.28 billion it disbursed in 2024.
What does the Lilly Endowment fund?
Founded in 1937 by members of the Lilly family, the foundation primarily funds religion, education, and community development, with a strong focus on Indianapolis and Indiana.