The 0.5% growth rate for 2025 was a sharp drop from 2024’s almost 1% growth rate, which was the highest in two decades and was fueled by immigration. The 2024 estimates put the U.S. population at 340 million people.

Immigration increased by almost 1.3 million people last year, compared with 2024’s increase of 2.8 million people. If trends continue, the gain from immigrants in mid-2026 will drop to only 321,000 people, according to the Census Bureau, whose estimates do not distinguish between legal and illegal immigration.

In the past 125 years, the lowest growth rate was in 2021, during the height of the coronavirus pandemic, when the U.S. population grew by just 0.16%, or 522,000 people and immigration increased by just 376,000 people because of travel restrictions into the U.S. Before that, the lowest growth rate was just under 0.5% in 1919 at the height of the Spanish flu.

Births outnumbered deaths last year by 519,000 people.

The immigration drop dented growth in several states that traditionally have been immigrant magnets.

California had a net population loss of 9,500 people in 2025, a stark change from the previous year, when it gained 232,000 residents, even though roughly the same number of Californians already living in the state moved out in both years. The difference was immigration since the number of net immigrants who moved into the state dropped from 361,000 people in 2024 to 109,000 in 2025.

Florida had year-to-year drops in both immigrants and people moving in from other states. The Sunshine State, which has become more expensive in recent years from surging property values and higher home insurance costs, had only 22,000 domestic migrants in 2025, compared with 64,000 people in 2024, and the net number of immigrants dropped from more than 411,000 people to 178,000 people.

New York added only 1,008 people in 2025, mostly because the state’s net migration from immigrants dropped from 207,000 people to 95,600 people.

South Carolina, Idaho and North Carolina had the highest year-over-year growth rates, ranging from 1.3% to 1.5%. Texas, Florida and North Carolina added the most people in pure numbers.

The effects of Trump’s immigration crackdown

Tuesday’s data release comes as researchers have been trying to determine the effects of the second Trump administration’s immigration crackdown after the Republican president returned to the White House in January 2025. Trump made a surge of migrants at the southern border a central issue in his winning 2024 presidential campaign.

The numbers made public Tuesday reflect change from July 2024 to July 2025, covering the end of President Joe Biden’s Democratic administration and the first half of Trump’s first year back in office.

The figures capture a period that reflects the beginning of enforcement surges in Los Angeles and Portland, Oregon, but do not capture the impact on immigration after the Trump administration’s crackdowns began in Chicago; New Orleans; Memphis, Tennessee; and Minneapolis, Minnesota.

The 2025 numbers were a jarring divergence from 2024, when net international migration accounted for 84% of the nation’s 3.3 million-person increase from the year before. The jump in immigration two years ago was partly because of a new method of counting that added people who were admitted for humanitarian reasons.

“They do reflect recent trends we have seen in out-migration, where the numbers of people coming in is down and the numbers going out is up,” Eric Jensen, a senior research scientist at the Census Bureau, said last week.

How the population estimates are calculated

Unlike the once-a-decade census, which determines how many congressional seats and Electoral College votes each state gets, as well as the distribution of $2.8 trillion in annual government funding, the population estimates are calculated from government records and internal Census Bureau data.

The release of the 2025 population estimates was delayed by the federal government shutdown last fall and comes at a challenging time for the Census Bureau and other U.S. statistical agencies. The bureau, which is the largest statistical agency in the U.S., lost about 15% of its workforce last year due to buyouts and layoffs that were part of cost-cutting efforts by the White House and its Department of Government Efficiency.

Other recent actions by the Trump administration, such as the firing of Erika McEntarfer as Bureau of Labor Statistics commissioner, have raised concerns about political meddling at U.S. statistical agencies. But Brookings demographer William Frey said the bureau’s staffers appear to have been “doing this work as usual without interference.”

“So I have no reason to doubt the numbers that come out,” Frey said.