The Great Wealth Transfer—the expected handoff of baby boomers' fortunes to their children—has long been pitched as the easy part of retirement. Boomers hold the money, and the money will move down to their children someday, increasingly soon. Or at least that is the idea.

Joe Coughlin, who founded MIT's AgeLab in 1999, thinks even the size of the handoff will prove slippery. Estimates range from $36 trillion to $124 trillion, a spread that drew a chuckle from him in a recent interview with Fortune.

For one of the world's foremost experts on longevity, the bigger problem is timing. The standard narrative assumes retirement at 65 followed by a relatively short stretch of life after that, but the 21st century seems to have other plans.

The Longevity Preparedness Index (LPI), a national benchmark created by life insurance company John Hancock Financial and the MIT AgeLab and shared exclusively with Fortune ahead of its release, measures how ready U.S. adults are for a long life after retirement. This year, Americans scored 60 out of 100, unchanged from last year, with care the weakest area measured. In other words, the country's readiness has not budged year over year—even as the debate over how long people might live now reaches toward 130 and beyond. That gap between lifespan and preparedness is the story behind the number.

That is a "solid D," said Wayne Park, who runs John Hancock's parent company Manulife's U.S. retirement business, in a separate interview with Fortune. Park suggested people might someday live as long as 130. He is not alone in that hypothesis: a University of Washington study published in 2021 estimated there is a 13% chance that at least one person in the 13 countries it analyzed would reach 130 years old by 2100, while Harvard's David Sinclair has suggested living to 150 is not outlandish at all.

Brooks Tingle, who runs John Hancock, remarked to Fortune that the retirement age of 65 "was sort of dreamt up…when people lived to 47." Societies still plan around that number, which is why the handoff schedule looks the way it does. Germany lowered its pension eligibility age from 70 to 65 in 1916, and the United States adopted 65 for Social Security in 1935.

Park called 65 "sort of an artificial milestone." He also believes the idea of the Great Wealth Transfer may be "overemphasized" so far. "The facts are that one transfers first to the spouse typically," he said. Longer lives stretch the process across what could be decades. A transfer will still happen, he said, but its size may have been exaggerated.

Women tend to partner with men a few years or more older, MIT's Coughlin noted, and they typically enter a second retirement after a husband dies. "For all the kids waiting for that great check in the sky," Coughlin said, "don't hold your breath."

The boomers, and who gets blamed

Coughlin explored the business implications of an aging population in his 2017 book, The Longevity Economy. He makes the case that the index is not a health survey. "Health and wealth are the bookends of a longer, better life," he said. "But in between, where are you going to live? What are you going to do? What are the transitions?" What he calls the longevity economy has mostly been about extending time and managing health up until now—an approach he describes as "not incorrect, but incomplete."

He is also the one who calls the LPI the first map of unfamiliar territory. "This is the first road map to try to sketch out what is that terra incognita out there of living longer, better," he said. Coughlin is writing a book about four retirements within retirement, he added, with the first stage being managing ambiguity, when people work out what retirement means and whether to keep working part-time. The other stages will be revealed in his forthcoming work—one to watch for anyone still working from the standard narrative of retiring at 65 into a comparatively short stretch of life.

Life stages are shifting elsewhere, too: the median first-time homebuyer's age reached a record 40 in the National Association of Realtors' 2025 survey. Asked about that milestone, Coughlin pointed to delays in other life stages, from driving to partnering and moving out. "We're creating new life stages," he said, "or we're extending life stages that used to be done in short order."

For Park, living longer means more years of income to fund, which puts pressure on both Social Security and personal savings. "There's going to be challenges because of the way our public system is set up," he said.

When asked about a clash of generations—boomers holding so much housing and stock market wealth while other generations wait impatiently for their turn on the wealth escalator—all three argued for looking beyond a simple generational fight over money, emphasizing the demands and opportunities of longer lives.

"The real generation gap is about expectations," Coughlin said. "Not only do [they] expect to live longer, but they expect to live better." Boomers were simply the first to expect both, he argued, because they watched technology change everything around them. Each generation afterward saw more change, which has made each one less willing to accept limits as natural.

Coughlin said millennials have inherited the boomers' reputation without the boomers' advantages. "You poor guys are getting treated the way the boomers did," he said. As for Gen Z, he came away impressed by a cohort forged in a crucible, saying its members may emerge as another Greatest Generation like the one that fought World War II. "They're not snowflakes. They're snowballs," he said. The young people he has talked to hold a rational distrust of the institutions supposed to protect them, because they watched those institutions fail their parents and older siblings. Their response has been to build a second income. One told him they needed a plan B "because I'm not sure that my employer is going to be there for me."

Coughlin was not all sunshine. Loneliness is highest among people between 18 and 25, he said, and the quarter-life crisis is real. He argued social media makes the expectations gap worse by letting young people measure themselves against everyone else's highlights. His well-being data shows satisfaction falling through the thirties and forties, with the low point between roughly 47 and 50, before it rises again.

Expectations cut both ways

Park insisted on caution. The pace of change in drugs such as GLP-1s and in AI is fast enough that nobody knows what 130 will look like. "The question is, are those 130 years going to be…are you going to be thriving for most of those 130 years, versus what it could be?" he said.

Care scored 43 on the index, the lowest of the eight areas measured—community, daily activities, finance, health, home, life transitions, and social connections, in addition to care. Park said the research suggests the job usually falls to the eldest daughter, often without her knowing anyone expects it of her. The MIT AgeLab often talks about the "eldest daughter" phenomenon, such as its research showing that 75% of unpaid caregivers are women, many of them family members.

Tingle's advice to people who feel attacked by these numbers is to treat the years as an opportunity. "You've got to be realistic," he said. "Yeah, you've got to prepare, you've got to plan, but it presents a tremendous opportunity."

Park said he has struggled to start this conversation at home. "I tried to have a conversation about my care," he said. "And last year, my daughter told me she had a boyfriend and just—that didn't happen," he laughed, adding that the conversation "went somewhere else." He ends where the index ends. "You're going to have an awkward conversation on Thanksgiving anyway," he said. "This is a really important one."

This story was originally featured on Fortune.com.