SEATTLE (AP) — Bill Gates says he will donate 99% of his remaining tech fortune to the Gates Foundation, which will now close in 2045, earlier than previously planned. Today, that would be worth an estimated $107 billion.

The pledge is among the largest philanthropic gifts ever — outpacing the historic contributions of industrialists like John D. Rockefeller and Andrew Carnegie when adjusted for inflation. Only Berkshire Hathaway investor Warren Buffett’s pledge to donate his fortune — currently estimated by Forbes at $160 billion — may be larger depending on stock market fluctuations.

Gates’ donation will be delivered over time and allow the foundation to spend an additional $200 billion over the next 20 years.

“It’s kind of thrilling to have that much to be able to put into these causes,” Gates said in an interview with the Associated Press.

His announcement Thursday signals both a promise of sustained support to those causes, particularly global health and education in the US, and an eventual end to the foundation’s immense worldwide influence. Gates says spending down his fortune will help save and improve many lives now, which will have positive ripple effects well beyond the foundation’s closure. It also makes it more likely that his intentions are honored.

“I think 20 years is the right balance between giving as much as we can to make progress on these things and giving people a lot of notice that now this money will be gone,” Gates said.

In a league of its own

The Gates Foundation has long been peerless among foundations — attracting supporters and detractors but also numerous unfounded conspiracy theories.

In addition to the $100 billion it has spent since its founding 25 years ago, it has directed scientific research, helped develop new technologies, and nurtured long-term partnerships with countries and companies.

About 41% of the foundation’s money so far has come from Warren Buffett and the rest from the fortune Gates made at Microsoft.

Started by Bill Gates and Melinda French Gates in 2000, the foundation plays a significant role in shaping global health policy and has carved out a special niche by partnering with companies to drive down the cost of medical treatments so low- and middle-income countries could afford them.

“The foundation work has been way more impactful than I expected,” Gates said, calling it his second and final career.

The foundation’s influence on global health — from the World Health Organization to research agendas — is both a measure of its success and a magnet for criticism. For years, researchers have asked why a wealthy family should have so much sway over how the world improves people’s health and responds to crises.

Gates said, like any private citizen, he can choose how to spend the money he earns and has decided to do everything he can to reduce childhood deaths.

“Is that a bad thing? It’s not an important cause? People can criticize it,” he said, but the foundation will stick to its global health work.

The Associated Press receives financial support for news coverage in Africa from the Gates Foundation and for news coverage of women in the workforce and statehouses from Melinda French Gates’ organization, Pivotal Ventures.

Major ambitions for the remaining 20 years

The foundation’s most prized metric is the drop in childhood deaths from preventable causes by almost half between 2000 and 2020, according to United Nations figures. The foundation’s CEO Mark Suzman is careful to say they do not take credit for this accomplishment. But he believes they had a “catalytic role” — for example, in helping deliver vaccines to children through Gavi, the vaccine alliance they helped create.

The foundation still has numerous goals — eradicating polio, controlling other deadly diseases, like malaria, and reducing malnutrition, which makes children more vulnerable to other illnesses.

Gates hopes that by spending to address these issues now, wealthy donors will be free to tackle other problems later.

The Gates Foundation had planned to wind down two decades after Gates’ death, meaning today’s announcement significantly moves up that timetable. Gates plans to stay engaged, though at 69, he acknowledged he may not have a say.

In its remaining two decades, the foundation will maintain a budget of around $9 billion a year, which represents a leveling off from its almost annual growth since 2006, when Buffett first started donating.

Suzman expects the foundation will narrow its focus to top priorities.

“Having that time horizon and the resources just puts an even greater burden on us to say, ‘Are you actually putting your resources, your thumb down, on what are going to be the biggest, most successful bets rather than scattering it too thinly?’” Suzman said, which he acknowledged was creating uncertainty even within the foundation about what programs would continue.

Gates is the only remaining founder

Major changes preceded the foundation’s 25th year.

In 2021, Melinda French Gates and Bill Gates divorced, and Buffett resigned as the foundation’s trustee. They recruited a new board of trustees to help govern the foundation, and in 2024, French Gates left to continue work at her own organization.

French Gates said she decided to step down partly to focus on countering the rollback of women’s rights in the U.S. At the ELLE Women of Impact event in New York in April, she said she wanted to leave the foundation at a high point.

“I so trusted Mark Suzman, the current CEO,” she said. “We had a board in place that I helped put in place, and I knew their values.”

Even as the foundation’s governance stabilizes, the road ahead looks difficult. Enduring conflicts in Ukraine and Gaza, global economic turmoil and cuts to foreign aid forecast fewer resources coming to global health and development.

“The greatest uncertainty for us is the generosity that will go into global health,” Gates said. “Will it continue to go down like it has the last few years or can we get it back to where it should be?”

Even facing these obstacles, Gates and the foundation speak, as they often do, with optimism, pointing to innovations they’ve funded or ways they’ve helped reduce the cost of care.

“It’s incredible to come up with these low-cost things and tragic if we can’t get them out to everyone who needs them,” Gates said. “So it’s going to require renewing that commitment of those who are well off to help those who are in the greatest need.”