In CBO’s projections, the U.S. population increases from 336 million people in 2023 to 373 million people in 2053. Population growth is increasingly driven by net immigration, which accounts for all population growth beginning in 2042.
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 size of the population ages 25 to 54 affects the number of people employed; likewise, the size of the population age 65 or older affects the number of beneficiaries of federal programs such as Social Security and Medicare. 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 later this year.
Population. In CBO’s projections, the Social Security area population—the relevant population for calculating Social Security payroll taxes and benefits and the measure of population used in this report—increases from 336 million people in 2023 to 373 million people in 2053. As growth of the population age 65 or older outpaces growth of younger age groups, the population is projected to continue to become older.
Population Growth. Population growth is generally projected to slow between 2023 and 2053, averaging 0.3 percent per year over that period. That growth will be increasingly driven by immigration as fertility rates remain below the rate that would be required for a generation to exactly replace itself in the absence of immigration.
Civilian Noninstitutionalized Population. The civilian noninstitutionalized population grows from 266 million people in 2023 to 301 million people in 2053, in CBO’s projections, expanding by 0.4 percent per year, on average. That measure, which CBO uses to project the size of the labor force, is composed of people age 16 or older. The subgroup of people ages 25 to 54 (adults in their prime working years) grows at an average annual rate of 0.2 percent over that period—more slowly than in recent decades. (Over the past 40 years, the civilian noninstitutionalized population as a whole grew at a rate of 1.1 percent, and the prime working-age population grew at a rate of 0.9 percent.)
Changes Since Last Year. The population is projected to be larger (by 0.8 percent in 2052, the final year of the projections that CBO released last year) and to grow slightly faster, on average, in this year’s projections, for two main reasons. First, net immigration is projected to be higher, boosting the size and growth of the working-age population over the 2023–2053 period. Second, mortality rates for people age 65 or older are projected to be lower over the first two decades of the projection period; that decline stems from fewer deaths in 2022 due to COVID-19 infections than CBO previously projected.
CBO’s projections of the rates of fertility, mortality, and net immigration are 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.