By: Staff Writer
August 4, 2026
The number of migrants who were living illegally in the United States swelled to an estimated record 15.8 million in 2024, up from 11 million people prior to 2010, with most from Central America, according to a report released by the Migration Policy Institute.
The report, “Following Years of High Border Arrivals, the U.S. Unauthorized Immigrant Population hits New Peak,” attributes the gains to more migrants coming from Central and South America to the Southwest border during the Biden administration, and fewer leaving, as had been the previous trend dating back to 2010.’
The report said: “As the size of the unauthorized immigrant population has increased since 2019, the share of immigrants who are from Central and South America has surged while the Mexican share has shrunk significantly. This trend reflects sharp increases in recent arrivals of Ecuadorians, Colombians, and especially Venezuelans, as well as steady growth in unauthorized arrivals from Guatemala and Honduras.
“These mid-2024 estimates, which derive from a unique MPI methodology, are based on the most recently available data from the U.S. Census Bureau’s American Community Survey (ACS).
“To incorporate improvements the Census Bureau has made in how it measures newly arrived immigrants and to correct for the historic undercounts of this population, MPI adjusted its methodology and revised upwards its estimates for 2021 through 2023. As a result, MPI’s revised estimate of the unauthorized population as of mid-2023 now stands at 14.7 million.”
For many years, MPI’s estimates of the overall unauthorized population hovered around 11 million, plus or minus a few hundred thousand. This stability occurred because entries into the unauthorized population were continually offset by exits.
For example, during the decade between 2010 and 2019, MPI estimates that roughly 6.1 million people crossed a border illegally or overstayed a visa, while 5.7 million unauthorized immigrants died, emigrated, or, less commonly, obtained legal status—resulting in a net increase of just 394,000 over that period.
Between 2019 and 2024, MPI estimates the unauthorized immigrant population experienced a net growth of approximately 5 million people, or an average of 8 percent per year. The increases were driven by the uncommonly strong U.S. economic recovery after the COVID-19 pandemic as well as the large-scale displacement from countries throughout the Americas fuelled by gang violence, political repression, and economic challenges.
As a result, irregular arrivals at the U.S.-Mexico border surged in fiscal year (FY) 2021 and peaked in FY 2023, bringing a rising mix of nationalities from across the Western Hemisphere and beyond, before dropping slightly in FY 2024. For instance, Venezuelan irregular arrivals started to grow quickly following the severe economic and political turbulence that began in Venezuela in 2015 and has continued.
Likewise, irregular migration from Honduras and Guatemala grew rapidly starting in 2019, including large shares of families, due to political instability and spells of agricultural stress that compounded the countries’ economic challenges. Irregular migration from Ecuador and Colombia also grew, due to episodes of insecurity and violence.