In CBO’s projections, the U.S. population increases from 342 million people in 2024 to 383 million people in 2054. Net immigration increasingly drives population growth, accounting for all population growth beginning in 2040.
The size of the U.S. population, as well as its age and sex composition, has significant implications for the economy and the federal budget. For example, the number of people ages 25 to 54 affects the number of people employed, and the number of people age 65 or older affects the number of Social Security and Medicare beneficiaries.
In this report, the Congressional Budget Office describes its population projections, which underlie the agency's baseline budget projections and economic forecast that will be published in early 2024.
Population. In CBO's projections, the Social Security area population—the relevant population for estimating Social Security payroll taxes and benefits and the measure of population used in this report—increases from 342 million people in 2024 to 383 million people in 2054. As growth of the population age 65 or older outpaces growth of younger age groups, the population continues to become older, on average.
Population Growth. Population growth generally slows over the next 30 years, from 0.6 percent per year, on average, between 2024 and 2034 to 0.2 percent per year, on average, between 2045 and 2054. Net immigration increasingly drives population growth and accounts for all population growth beginning in 2040, in part because fertility rates remain below the rate that would be required for a generation to replace itself in the absence of immigration.
Civilian Noninstitutionalized Population. The civilian noninstitutionalized population—which consists of people age 16 or older who are not members of the armed forces on active duty and who are not in penal or mental institutions or in homes for the elderly or infirm—grows from 271 million people in 2024 to 310 million people in 2054, expanding by 0.4 percent per year, on average. The number of people ages 25 to 54 (who are more likely to work than people in other age groups) grows at an average annual rate of 0.3 percent over that period—more slowly than in recent decades.
Changes Since Last Year. The Social Security area population is projected to be larger (by 2.4 percent in 2053) and to grow slightly faster, on average, than CBO projected last year. Upward revisions to net immigration from 2024 to 2026, which boost the size and growth of the population ages 25 to 54 in particular, account for most of that difference. Partially offsetting that change is a reduction in the projected total fertility rate, from 1.75 to 1.70 births per woman. CBO also reduced its projection of mortality rates for people age 65 or older over the first two decades of the projection period, reflecting fewer deaths due to COVID-19 than the agency previously projected.
CBO's projections of the rates of fertility, mortality, and net immigration are highly uncertain. Small differences between CBO's projections of those rates and actual outcomes could compound over many years and significantly alter demographic outcomes by the end of the projection period.