In 2024, he gave a total of $3.7 billion to support arts, education, the environment, public-health groups, and programs aimed at improving city governments. He gives directly to charities and through his Bloomberg Philanthropies, which last year awarded a $1 billion grant to his alma mater, Johns Hopkins University, to make medical school free and to provide financial aid to nursing and public health students.

“I’ve never understood people who wait until they die to give away their wealth. Why deny yourself the satisfaction?” he wrote in an email to the Chronicle. “I’ve been very lucky, and I’m determined to do what I can to open doors for others and to leave a better world for my children and grandchildren.”

Bloomberg was one of six donors who gave $1 billion or more in 2024. The others were Netflix co-founder Reed Hastings and his wife, Patty Quillin (No. 2), Dell Technologies founder Michael Dell and his wife, Susan Dell (No. 3), investor Warren Buffett (No. 4), Facebook co-founder Mark Zuckerberg and his wife, physician Priscilla Chan (No. 5), and retired professor Ruth Gottesman (No. 6).

The majority of those gifts went to foundations and donor-advised funds that support causes including education, economic mobility, social justice, and scientific research. Gottesman, like Bloomberg, gave to make medical school free. She donated $1 billion to the Albert Einstein College of Medicine.

Together the 50 donors on the list contributed a total of $16.2 billion to charity in 2024. The median amount they gave was $100 million.

While those numbers are sizable, not all of the nation’s wealthiest people appear on the list. Only 19 of the richest Americans on the Forbes 400 list donated enough to appear in the Philanthropy rankings.

Among those who gave big — but are less well known:

— Thomas Golisano, the billionaire founder of Paychex, is No. 8. He gave away $500 million last year. Almost $400 million of that went to 123 nonprofits in New York and Florida with no strings attached. About 90 of those gifts were $1 million to $5 million, often to small groups that rarely get contributions of that size. Many were to organizations that serve people with developmental, intellectual, and physical disabilities. The issue has great meaning to Golisano, whose son has a developmental disability.

— Retired insurance executive Hyatt Brown and his wife, Cici, at No. 20, gave the Museum of Arts & Sciences, in Daytona Beach, Fla., $150 million for a new building and to turn its current home into a children’s museum.

— Businesswoman and venture capital investor Michele Kang, at No. 28, gave $84 million last year, including $4 million to help the USA Women’s Rugby Sevens team prepare for the Olympics.

Some big public debates have been swirling in the world of philanthropy. Some donors — most notably hedge-fund billionaire Bill Ackman — pushed back against the institutions they have supported, criticizing universities’ responses to the October 7 attacks in Israel and campus protests against the war in Gaza; critiquing diversity, equity, and inclusion programs; demanding changes; and pledging to halt support.

Some philanthropists believe that politicized public debates about giving are unhelpful noise that can get in the way of doing effective work. K. Lisa Yang (No. 34), a retired investment banker, gave $74.5 million this year, much of that to MIT and Cornell University, where she is a trustee.

Over the years, Yang has given large sums to programs that help people who are physically or cognitively disabled, and she advocates for individuals with disabilities and autism-spectrum disorders.

“The people who are suffering from these disorders, they don’t have the luxury of time,” she says. “When you have a rare disease and they do politics, to the people who are suffering from the disorder, it is totally irrelevant. They’re still suffering.”

But some donors are loath to get ensnared in high-profile polarizing issues, says Renee Kaplan, CEO of the donor advisory firm Forward Global. As a result, she says, some donors are staying out of the fray by making anonymous gifts. Others are working together in donor collaboratives, both to boost their power and resources and to shield individual contributors from criticism.

Donors are starting to say, “I’ll do more anonymously. I’m not going to put my name on things. I’m going to slow down our foundation for a while because I’m worried I’ll be a target,” Kaplan says. “I think there’s genuine concern and pause and fear that’s affecting donors.”

This year’s list marks the 25th anniversary of the Philanthropy 50 ranking. Buffett was the top donor over that period, with cumulative gifts totaling $49.4 billion. Microsoft co-founder Bill Gates and Melinda French Gates followed, with the $34 billion they gave together. (Since their divorce, both have appeared on the list individually.) Bloomberg, Jeff Bezos, and Elon Musk round out the top five.

Buffett, Gates and French Gates, and Bloomberg together account for roughly one-third of the $314.5 billion in giving by Philanthropy 50 donors since 2000. The biggest gift made during that time is Buffett’s 2006 pledge to the Gates Foundation, valued at the time at $36.1 billion.