In the United States, you must be aged 66 or 67 to receive full Social Security retirement benefits. But should retire then? According to the experts, when is the healthiest time to retire?

Nearly half of Americans between the ages of 60 and 75 plan to work part-time after retirement, and almost 25 percent say they will retire after age 70 or not at all. These statistics aren’t surprising given that seniors and their financial welfare have experienced three recessions and a global pandemic. Happily, modern medicine means people are healthier and living longer, making 66 seem more like “mid-life” and not a financially viable time to retire.

If you’re looking to science for the magic number, be prepared for conflicting answers.

On the one hand, a 2017 Dutch study linked early retirement to a longer lifespan. It found that men who retired between 55 and 65 had a mortality risk 2.6 percentage points lower than those still employed over the next five years. Similar studies have found that retiring early lowers your physical health risk.

Conversely, other studies conclude that delayed retirement increases your chances of living a longer, healthier life. One 2020 Amsterdam report led neurologist Daniel Levitin to suggest that it’s best not to retire at all. “Stay busy!” Levitin writes in his book Successful Aging: A Neuroscientist Explores the Power and Potential of our Lives. “But not with busy-work or trivial pursuits, but with meaningful activities.”

In the end, it sounds like the optimal retirement age is as diverse as the individual considering it.