Illegal Population Down Since January

 Our analysis of the Bureau of Labor Statistics household survey, officially called the Current Population Survey (CPS), shows a large decline in the foreign-born or immigrant population (legal and illegal) between January and May of this year. The decline was caused by a falloff in the number of non-citizens from Latin America who arrived in 1980 or later, a population that overlaps significantly with illegal immigrants. We preliminarily estimate that the number of illegal immigrants has fallen by one million since the start of the year, perhaps due to their leaving in response to President Trump’s election and stepped-up enforcement efforts. But it is important to note that these findings come with important caveats.

Findings: 

• Based on the CPS, published figures from the Bureau of Labor Statistics show that the number of foreign-born individuals in the labor force declined by 601,000 from January to May 2025.
• Our analysis of the raw data shows the total foreign-born population, both in and out of the labor force, declined 957,000 from January to May 2025. This is one of the largest declines over a 4-month period in the foreign-born in the last three decades, but it is not unprecedented.
• The decline was entirely among non-citizens. The number of naturalized U.S. citizens in the data did not fall from January to May of this year.
• In particular, non-citizens from Latin America who indicated they arrived in the United States in 1980 or later show a 1.07 million decrease from January to May of this year and a 1.45 million falloff since December 2024.
• It is well-established that the post-1980 Latin American non-citizen population overlaps significantly with the illegal immigrant population.
• Our preliminary estimate is that there are 14.8 million illegal immigrants in the country in May 2025, one million fewer than we estimated in January of this year.
• There are important caveats about all of these numbers: 1) Though the decline in non-citizens is statistically significant, the decline in the total foreign-born is not. 2) Given recent stepped-up enforcement efforts, it is possible that the decline was due, at least in part, to a greater reluctance by immigrants to participate in the survey or to identify as foreign-born rather than an actual falloff in their numbers. 3) Finally, some of the administrative data necessary to estimate illegal immigrants is not yet available, making our estimate for May only preliminary. 

Introduction

Some reporting has focused on the decline of immigrants in the labor market. This analysis goes deeper and uses the public use the Census Bureau’s Current Population Survey, colloquially known as the household survey, to measure recent trends in the foreign-born population in and out of the labor force through May of this year. The foreign-born in Census Bureau surveys includes all persons who were not U.S. citizens at birth – mainly naturalized citizens, lawful permanent residents (green card holders), long-term temporary visitors (e.g. guest workers and foreign students), and illegal immigrants. Both the Census Bureau, which collects the Current Population Survey (CPS), and the Bureau of Labor Statistics, which reports employment trends based on the data, are clear that the survey includes illegal immigrants, though some are missed. We use the terms “immigrant” and “foreign-born” interchangeably in this analysis.¹ 

As the Center has already reported in a prior publication, the foreign-born hit historic highs numerically and as a share of the U.S. population in January 2025 based on the monthly Current Population Survey (CPS). The January CPS was the first government survey to be weighted to reflect the enormous increase in net international migration that the Census Bureau now estimates due to the Biden administration’s border surge.² The larger American Community Survey (ACS), often used to study immigrants, cannot be used to measure recent trends because it has not been weighted to reflect the Census Bureau’s new migration estimates and only shows the population through July 2023. Using the CPS allows for much more up-to-date analysis. 

Findings

Trends in the Total Foreign-born. Figure 1 reports the total foreign-born population in the United States from January 2021 to May 2025. There is certainly variation in the data, but the trend has been upward in the preceding four years. However, since January 2025 the trend has been in the other direction, declining 957,000 since the start of this year. This is a substantial decline, indicating something fundamental may have changed. Since January of 1994 when the survey began to ask about citizenship, there have only been a few other times when the foreign-born population fell by this much over only a 4-month time period. Variation of this size may represent a real change in the country, or it may reflect the normal sampling error in the data. In fact, although the decline from January to May is large, it is not statistically significant based on the most recent information provided to outside researchers by the Census Bureau for calculating significant changes in the CPS for the foreign-born.³

Decline in Immigrants Responding to the Survey. Like virtually all government and non-government surveys, the CPS is weighted to reflect the size and composition of the total population. The weights are based on Census Bureau estimates of births, deaths, and net international migration. The total population is controlled to certain key demographic variables such as race, sex, age, and Hispanic origin.⁴ Citizenship and country of birth are not control variables and are allowed to vary based on responses to the survey, as is the case for, say, unemployment or income. The unweighted CPS from January to May of this year shows a decline in the number of foreign-born respondents of 3.7 percent.⁵ By contrast, in the prior four years, the number of immigrants in the sample had grown every year from January to May. This falloff is another indication that prior trends have reversed. 

Decline in Non-citizens. Figure 2 shows that the decline in the foreign-born has been entirely among those who are not U.S. citizens. The number of non-citizens is down 1.4 million since January, while the number of naturalized citizens increased by a little over 400,000.⁶ In FY 2024 about 70,000 lawful permanent residents naturalized per month on average, so the recent increase is not surprising. Since illegal immigrants are not citizens, the decline in the number of people who are not American citizens is consistent with what would be expected if the number of illegal immigrants fell. 

Non-citizens from Latin America. Respondents to the CPS are asked when they came to the United States. Illegal immigrants should show up in Census Bureau surveys as having arrived in 1980 or later due to the 1986 IRCA amnesty.⁷ This is why our estimate of illegal immigrants, and that of DHS, both subtract the legal immigrant population from the total post-1980 foreign-born in Census Bureau data to arrive at the number of illegals.⁸ As already mentioned, most illegal immigrants should also identify as non-citizens. Also, prior research by DHS, the Pew Research Center, the Center for Migration Studies, and the Migration Policy Institute all indicate that roughly three-fourths of illegal immigrants are from Latin America.⁹ We also know that 84 percent of those encountered at the nation’s borders from January 2021 to April 2025 are from Latin American countries. As a result, the size of the non-citizen Latin American population who arrived in 1980 or later is highly correlated with the illegal immigrant population. 

Figure 3 shows this population from January 2021 to May of this year. The number of post-1980 Latin American non-citizens increased relatively steadily from January 2021 to December 2024, which is what we would expect given the border surge and the number of people flown into the country and released under the CHNV program. But from January to May 2025, the number of post-1980 Latin American non-citizens declined by 1.07 million. Unlike the decline in the total foreign-born, the decrease for post-1980 non-citizen Latin Americans is statistically significant at a .99 confidence level.¹⁰ The decline from December 2024 to May of this year is even larger at 1.45 million.¹¹ These results strongly support the idea that the election of Donald Trump, his rhetoric, and high-profile enforcement actions as soon as he took office caused a large number of illegal immigrants to leave the country.

Illegal Immigrants. The Center has used the Current Population Survey in the past to estimate the illegal immigrant population in the United States. The survey does not specifically identify illegal immigrants; but like other researchers we use the information in the survey, and other information from outside the survey, to estimate the population living in the country without authorization.¹² As we have described in our earlier analysis, we follow DHS’s Office of Homeland Security Statistics approach and first estimate the legal immigrant population that arrived in 1980 or later, allowing for deaths and outmigration, and then subtracting this estimate from the foreign-born population in the survey, specifically those who arrived in 1980 or later.¹³

In our report on the January 2025 CPS, we found 46.8 million post-1980 immigrants in the CPS. We further estimated that there were 31.4 million post-1980 legal immigrants in the January 2025 CPS.¹⁴ Subtracting the number of legal immigrants from the total post-1980 foreign-born produced an estimate of 15.4 million illegal immigrants in the January survey, which we adjusted up to 15.8 million for undercount. All the administrative data needed to estimate the legal immigrant population in May 2025 is not yet available.¹⁵ But based on prior trends and what limited information is available, we preliminarily estimate that the post-1980 legal immigrant population grew to 31.7 million by May of this year. Subtracting this number from the 46.13 million post-1980 immigrants in the CPS produces an estimate of 14.4 million illegal immigrants in the May data. This is one million fewer than our January estimate. If we make the same modest adjustment for undercount as we have done in the past, then the illegal immigrant population in May was 14.8 million or roughly one million fewer than our estimate of 15.8 million for January 2025 (see Figure 4).

Caveats about a Decline in Illegals. There are important caveats about concluding that the illegal population has declined based on the numbers presented here. As we discussed, although the falloff in the non-citizen population overall is statistically significant, as is the decrease for post-1980 non-citizens from Latin America, the overall decline for the foreign-born is not. Another reason for caution is that given recent stepped-up enforcement efforts, it is possible that immigrants, especially illegal immigrants, have become more reluctant to respond to the CPS or if they do respond are less willing to indicate they are foreign-born. This could create the appearance of a decline when it fact none has occurred.¹⁶ The 3.7 percent decline in the number of unweighted immigrants in the survey from January to May 2025 could indicate this is happening. However, a decrease in the number of immigrants is also consistent with an actual decline in the foreign-born. Finally, our estimate of illegal immigrants is based on incomplete data for May 2025, increasing uncertainty about our specific estimate of illegal immigrants. All of these factors need to be kept in mind when interpreting the figures presented here. 

Conclusion

This analysis shows that the number of foreign-born residents in the country declined by nearly a million in the Current Population Survey from January to May 2025. While this falloff is not statistically significant, we do find statistically significant declines in the number of residents who are not U.S. citizens and the number of non-citizens from Latin America who arrived in the United States in 1980 or later. The post-1980 Latin American non-citizen population in particular overlaps significantly with the illegal immigrant population. Finally, our preliminary estimate of the illegal immigrant population shows a decline of one million from January to May 2025 in the survey. 

A large decline in the number of illegal immigrants could be very helpful to less-educated U.S.-born and legal-immigrant workers, whose wages may rise as a result. Further, a tighter labor market and higher wages may help to draw back into jobs the near-record number of working-age American men without a college degree not in the labor force.

We believe there is good evidence the illegal immigrant population has fallen considerably since January. This reverses the trend in the prior four years in which the illegal population grew substantially. However, this conclusion comes with important caveats, stemming directly from the limitations in the available data.

Endnotes