As of last year, people aged 65 and older made up the largest share of the U.S. population over age 16, a trend that started in 2008 as baby boomers aged. Meanwhile, Americans between the ages of 16 and 24 represent the smallest proportion of the population and those between the ages of 45 and 54 make up the second smallest share.

This population shift has implications for the U.S. labor force as the large contingent of people over age 65 increasingly make up a smaller proportion of the labor force, according to an Employee Benefit Research Institute issue brief. The report examined the U.S. labor force through December 2023 using data from the U.S. Census Bureau's Current Population Survey.

"At present, the aging of the baby boom generation has resulted in an increased share of older individuals in the labor force. However, members of this generation are almost all at least in their 60s, and the next generation (Gen X) is much smaller, so a decrease in the share of workers ages 55 or older is likely to follow," said EBRI. "Working longer not only has implications for companies, but also for the individuals themselves, as working into older ages can lead to the accumulation of more assets, less need to deplete assets already accumulated, and a delay in claiming Social Security benefits."