CBO, Report: The Demographic Outlook, 2023 to 2053

“The size of the U.S. population, as well as its age and sex composition, affects the economy and the federal budget. For example, the number of people who are employed depends on the size of the working-age population, and the number of beneficiaries of federal programs (including Social Security and Medicare) depends on the size of the elderly population.”

“In CBO’s projections, the population increases from 336 million people in 2023 to 373 million people in 2053, growing by 0.3 percent per year, on average, about one-third the pace experienced from 1983 to 2022 (0.8 percent). Over the next decade, immigration accounts for about three-quarters of the overall increase in the size of the population, and the greater number of births than deaths accounts for the remaining one-quarter. After 2033, population growth is increasingly driven by net immigration, which accounts for all population growth beginning in 2042.”