Have 1.6 million undocumented immigrants left the U.S. this year? Researchers say it's too soon to know.

Have 1.6 million undocumented immigrants left the U.S. this year? Researchers say it's too soon to know.

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Homeland Security Secretary Kristi Noem said last week that the number of unauthorized immigrants living in the U.S. has declined by 1.6 million since President Trump began his

"This is massive," Noem said in a statement, crediting the decline in part to an ad campaign warning undocumented immigrants to leave or face

"This new data shows illegal aliens are hearing our message," she added. In the Department of Homeland Security's , Noem did not specify how many of those individuals were believed to have departed the U.S. voluntarily, versus those who have been deported. 

But the vast majority would have had to have left without making any contact with DHS to reach that total. According to previously obtained by TheNews, over the first six months of President Trump's second term, the administration deported nearly 150,000 people and recorded 13,000 who self-deported. 

A DHS spokesperson told TheNews that it sourced the 1.6 million figure from its own numbers out of U.S. Citizenship and Immigration Services, although its included a chart from an released earlier this month by the Center for Immigration Studies, a group that supports immigration restrictions. 

It did not provide additional information on how USCIS calculated this estimate. 

Any estimate of the current unauthorized population at this stage comes with caveats, researchers who study population demographics told TheNews, and it's too early to conclude that there's been a mass exodus. 

A new from the Pew Research Center, released Thursday, estimated that there were 14 million unauthorized immigrants living in the U.S. as of 2023. That's the latest year for which data from the Census Bureau's is available — the survey that experts say is the gold standard for making these population estimates. 

The Pew Research Center's analysis found that the undocumented immigrant population swelled by 3.5 million from 2021 to 2023, driven largely by recent arrivals during the Biden administration. 

It had previously declined by 1.1 million between the start of the Obama administration and the end of the first Trump administration, Pew found. 

Meanwhile, the analysis from the Center for Immigration Studies is based on another Census Bureau survey the Current Population Survey. The CPS polls about 60,000 households — about 2% of the size of the American Community Survey's sample — making some estimates less reliable. Experts also note some immigrants may not respond amid increased enforcement.

The Pew Research Center analyzed the CPS data as well, and found similar results, showing the unauthorized immigrant population may have continued to grow into 2024 and started to decline in 2025.

"For [20]25, all we have is CPS data and that points to a decline from a January peak of immigrants," Jeffrey Passel, the Pew report's lead author, told TheNews. "How big the decline is could be affected by the decrease in response rates." 

To estimate the unauthorized population, researchers typically subtract the number of immigrants with legal status from the overall foreign-born population. Estimating the foreign-born population in the absence of the American Community Survey can be tricky. 

The Census Bureau, which oversees both surveys, against using the Current Population Survey to estimate the foreign-born populations due to its sample size. 

Zooming in on the foreign-born population within the CPS survey makes a small sample size even smaller, introducing wide margins of error, experts say. The foreign-born population makes up about 14% of the total U.S. population, according to the latest ACS survey. 

The analysis from the Center for Immigration Studies estimated that the total foreign-born population, which includes both legal and illegal immigrants, fell by 2.2 million between January and July, including 600,000 non-citizens with legal status.  

Steven Camarota, the lead author on that analysis, said the decline in the overall foreign-born population is statistically significant, or not due to chance, despite the wide margins of error. He noted that response rates have declined for , but haven't prevented the survey from tracking the previous in the foreign-born population prior to January 2025. 

Data is not available on the response rates among foreign-born people compared with U.S.-born people surveyed, so it isn't clear how much of the recent decline in the response rate is reflective of a drop off among immigrants. 

"Given that the foreign-born is a small minority of the population, you can have a meaningful decline in the foreign-born response rate without having much of a decline in the overall response rate," Jed Kolko, an economist who served as under secretary of commerce for economic affairs during the Biden Administration, told TheNews. 

Still, Kolko said there are other indicators that the unauthorized population has begun to decline. Industries that rely heavily on labor from unauthorized workers, , hotels and restaurants, have seen greater drops in employment than all other industries, according to his analysis of a Bureau of Labor Statistics survey of employers rather than households.