A crowded pedestrian walkway illustrates the demographic pressures facing the United States, where new federal projections warn that immigration will be the decisive factor in preventing population decline by 2031.
CBO projects deaths will outnumber births by 2031 as aging accelerates
WASHINGTON, D.C. — The United States could begin losing population as early as 2031 if immigration were to stop, according to new federal projections. The forecast highlights how dependent the nation’s demographic future has become on people moving to the country from abroad.
The Congressional Budget Office (CBO), in its updated long-term outlook, projects that deaths will outnumber births starting in 2031, two years earlier than previously estimated. That turning point—known as natural decrease—reflects both persistently low fertility rates and the rapid aging of the Baby Boomer generation. Without immigration to fill the gap, the U.S. population would begin to contract in the early 2030s.
Recent census data show how immigration already drives growth. Between 2023 and 2024, net international migration accounted for about 84 percent of the nation’s population gains, while births contributed only modestly. Federal health data recorded 3.62 million births in 2024, a 1 percent rise from the prior year, but still far below the level needed to offset rising deaths.
The CBO now estimates the U.S. population will reach about 367 million by 2055, a downward revision from its earlier projection of 372 million. The lower figure reflects not only fewer expected immigrants but also fertility rates that remain well below replacement levels.
These demographic trends carry far-reaching implications. A shrinking population would reshape the labor market, strain programs like Social Security and Medicare, and heighten demand for caregivers as the country grows older. If immigration continues at historical levels, the U.S. will still expand, albeit slowly. But if inflows are sharply curtailed, overall contraction could begin within the next decade.
Although long-range projections come with uncertainty, the direction is consistent across federal data: natural increase is no longer enough to sustain population growth. Immigration has become the decisive factor determining whether the United States expands or begins to shrink.
