WASHINGTON – President Joe Biden is about to have a lot more free time. He need look no further than past presidents for ideas on what to put on his retirement to-do list.

At age 82, Biden is the oldest U.S. president. In a recent interview with USA Today, he acknowledged uncertainty about his future stamina, saying, “Who knows what I’m going to be when I’m 86 years old?”

But his age isn’t remarkable for former presidents, nine of whom lived past 90. They include George H.W. Bush, Gerald Ford, Ronald Reagan, John Adams, Herbert Hoover and Jimmy Carter, who recently died at 100.

A look at some traditional — as well as a few decidedly less conventional — ways Biden might spend his upcoming years:

Try to bolster his place in history

Unlike his presidential predecessor-turned-successor, Donald Trump, Biden almost certainly won’t try a political comeback.

The Democrat has said little publicly about his post-Oval Office plans. Those who have long known him say it’s not something he’s discussed much beyond a tight circle of close aides.

Some modern former presidents have collected large fees for post-White House speaking engagements. Biden, who was plagued most of his term by low approval ratings, could use such appearances to try to bolster his legacy and future popularity. He told USA Today that he wanted his legacy to be having worked “to restore the economy and reestablish America’s leadership in the world.”

The good news for Biden is that presidents often see their popularity improve after leaving office.

Republican George W. Bush was unpopular at the end of his term amid the Iraq War and the financial crisis. But he became more favorably viewed in subsequent years, despite keeping a low public profile while taking up painting. Trump was similarly dogged by low approval ratings throughout his first term, but won back the White House in November.

Fundraise and plan for a presidential library

A priority for Biden is likely to be fundraising and beginning work on plans for his presidential library. It probably would be in Biden’s home state of Delaware, where he was a senator for 36 years and spent many weekends while president.

Officials have already enlisted at least one Biden administration ambassador to help with fundraising. A model can be the Barack Obama Presidential Center, a 19.3-acre (0.08-square-kilometer) library and museum in Chicago. Work began three years ago, with completion expected in 2026.

Sort through keepsakes — carefully

Biden can be something of a pack rat, aides say, and may want to hang on to memorabilia from his White House years. He needs to proceed with caution.

Federal elected officials are required to relinquish official documents and classified materials when they leave office. Biden’s personal lawyers have been working on careful document management since even before classified material from Biden’s time in the Senate and as vice president was found at the Penn Biden Center in Washington and in Biden’s Delaware garage.

Those discoveries followed an FBI search in 2022 on Trump’s Florida club, part of a documents case that was scrapped after he won back the White House. In Biden’s case, special counsel Robert Hur later released a report impugning the president’s age and mental competence but didn’t seek criminal charges over mishandled documents.

“We are going to do our best, certainly, to be careful to follow the rules, to do this the right way,” White House press secretary Karine Jean-Pierre said when asked about document retention on Friday.

Write another memoir — also carefully

Biden hasn’t expressed much interest, those close to him say, in writing another book. He’s written two memoirs, “Promises to Keep” published in 2007, and “Promise Me, Dad,” released in 2017.

He might eventually opt to work on a third, though, to help cement his aforementioned legacy. Again, he would need to proceed with caution.

Hur accused Biden of being sloppy about sharing classified information with ghostwriter Mark Zwonitzer, who worked on Biden’s first two books. The special counsel considered charging Zwonitzer with obstruction of justice because the ghostwriter destroyed recordings of interviews he conducted with Biden while they worked on his second memoir.

Ultimately, Hur’s report said Zwonitzer offered “plausible, innocent reasons” for having done so and subsequently cooperated with investigators.

Revel in the ex-president’s club

A longtime enthusiast of political tradition, Biden could well embrace membership in the ex-presidents club. The former commanders in chief from time to time pose for pictures and pat one another on the back while milling around at historic events — and sit together at VIP funerals.

Former presidents also sometimes take on special projects together such as promoting vaccines during the COVID-19 pandemic or raising money after natural disasters. They rarely criticize one another and tend to offer even fewer harsh words about current White House occupants.

This will be a chance for Biden to again differentiate himself from Trump, who showed little interest in spending time with former presidents after losing his 2020 reelection bid. That was similar to how he shunned typical post-presidency endeavors like working on building a presidential library, instead concentrating on his 2024 campaign.

Biden already convened his own former presidents club of sorts while still in office: He prepared for his State of the Union address last March by holding a video call with actors who had previously played presidents.

Morgan Freeman, Tony Goldwyn, Geena Davis and Michael Douglas offered advice and encouragement, as did Bill Pullman, who played President Thomas J. Whitmore in “Independence Day.” Pullman seized on Biden’s ever-present optimism in his public comments to predict, “People, when they look at all that you’ve managed to do, they’re gonna remember. Time will remember, always, your words.”

Try his hand at show business?

Speaking of celebrities, Biden has floated the idea of more glitzy post-presidential pursuits.

In August, about a month after he scrapped his reelection campaign, Biden joked at an event for online content creators: “That’s why I invited you to the White House — because I’m looking for a job.”

When Jessica Alba helped celebrate Hispanic Heritage Month at the White House a few weeks later, Biden joked that he might soon need the star’s business connections to help find work, saying, “Jessica, if I’m really good, maybe you can get me a job?”

He offered a similar joke at a December event for Kennedy Center honorees, telling Robert De Niro, “If I get in trouble, I’m coming to you, pal.”

“I’m looking for work in February,” Biden said to laughter. “Maybe you’ve got something for me? A Biden-De Niro combination? I can’t sing, I can’t act, I can’t dance, do a damn thing – but I could help ya.”