llegal Immigrant Population Was About 13.5 Million in July 2026

Based on Census Bureau data, we estimate that 13.5 million illegal immigrants live in the U.S. as of July 2026, down from 15.8 million when President Trump began his second term in January 2025. The mistaken belief that the illegal population actually numbers 20-30 million probably stems from underestimating the scale of associated legal immigration, including birthright citizens. By contrast, claims that there are 100-plus million illegal immigrants have no basis in reality.

Counting Illegal Immigrants

The Center’s latest report on the size of the overall foreign-born population includes a section on counting illegal immigrants. In brief, we use the Census Bureau’s Current Population Survey (CPS) to first estimate the legal immigrant population that arrived in 1980 or later, allowing for deaths and outmigration, and then subtract this estimate from the foreign-born population in the survey. (Those who arrived before 1980 are almost certainly not here illegally.) We define illegal immigrants as all foreign-born residents who are not naturalized citizens, permanent residents, or temporary visa-holders. Following convention, we include those with some temporary protections from deportation, such as parolees and asylum applicants, as illegal immigrants.

Based on prior trends and the limited administrative data available, we estimate that the post-1980 legal immigrant population was 31.6 million in July 2026. Subtracting this number from the 44.7 million post-1980 immigrants in the July CPS produces an estimate of 13.1 million illegal immigrants in the data. A standard adjustment for undercount puts the total illegal immigrant population at 13.5 million in July 2026. As Figure 1 shows, this marks an extraordinary decline of 2.3 million, or 14.6 percent, in the illegal immigrant population since January 2025.