As of early 2025, estimates of the number of illegal (unauthorized) immigrants in the United States vary depending on the source and methodology:
- The Center for Immigration Studies (CIS) estimated about 15.4 million illegal immigrants in January 2025 by subtracting an estimated 31.4 million legal post-1980 immigrants from a total of 46.8 million post-1980 immigrants (legal and illegal combined)
- The Federation for American Immigration Reform (FAIR) estimated approximately 18.6 million illegal aliens residing in the U.S. as of March 2025, which is 11% higher than their estimate from June 2023
- Pew Research Center reported the unauthorized immigrant population was about 11 million in 2022, up from 10.5 million in 2021, but still below the 12.2 million peak in 2007
- The Office of Homeland Security Statistics (OHSS) estimated about 11 million unauthorized immigrants living in the U.S. as of January 2022, noting some recent increases after a prior decline
- The Migration Policy Institute (MPI) estimated around 11.2 million unauthorized immigrants in 2021, with growth since 2019
These differences arise from varying definitions, data sources, and estimation methods. The lower estimates (around 11 million) come from government and research organizations relying on surveys and administrative data, while higher estimates (15 to 18 million) come from organizations using different assumptions or broader definitions. In summary, credible estimates for the current unauthorized immigrant population in the U.S. generally range from about 11 million to as high as 18.6 million in early 2025, with many experts placing it near 11 to 15 million
