It's not just Joe Biden. Lots of Americans are working into their 80s.

Although the share of Americans age 80 and over with a job has tumbled some from it's high in 2018 per Insider's analysis, there are still plenty of older workers working past typical retirement age.

That could be due to a desire for purpose, a need for an income, or medical advancements that keep people more able to work into their golden years.

Johnson also credited modern healthcare advances with enabling people over the age of 80 to enjoy "higher functioning health for longer than in the past," and said that older people will often remain in the workforce, retire to start businesses, or volunteer in order to stay mentally stimulated, what she calls a "working retirement." .

Research confirms the health benefits of that fulfillment: a 2018 study published by the Center for Retirement Research showed that "working longer is associated with lower mortality, depression, and diabetes risk for both men and women.".

"Workers ages 80 and up are not as likely to be motivated by health insurance and retirement benefits, since they are Medicare-eligible and already receiving Social Security benefits," Courtney Coile, professor of economics at Wellesley College and co-director of the NBER Retirement and Disability Research Center, told Insider in a statement.

"There are many factors contributing to people working longer — these include improving health and longevity, rising education and a shift towards more 'age-friendly' jobs in the economy, and changes in retirement benefits, such as the shift from defined benefit to defined contribution plans in employer-provided pensions and an increase in the Social Security full retirement age," Coile said.

However, not all older Americans want to keep working as they get older and will exit the labor force

Are you still working at 80 years old or older and want to share your story