The Migration Policy Institute (MPI) today released its latest estimates of the size of the unauthorized immigrant population in the United States, pegging the number at 15.8 million in mid-2024, after hovering in the 11 million range throughout the decade beginning in 2010.
The increase is primarily driven by record unauthorized arrivals at the U.S.-Mexico border and the Biden administration’s wide use of humanitarian parole programs to reduce chaos at the border. As a result of these grants of parole and other Biden administration moves, MPI estimates that, as of mid-2024, a maximum of 40 percent of unauthorized immigrants in the United States held a liminal (or “twilight”) status providing them temporary protection from deportation, such as Temporary Protected Status (TPS), Deferred Action for Childhood Arrivals (DACA), humanitarian parole or pending asylum application.
The MPI estimates, developed in concert with Jennifer Van Hook, a demographer at The Pennsylvania State University’s Population Research Institute, derive from a residual method that subtracts estimates of the legally resident foreign born from the total immigrant population recorded in the U.S. Census Bureau’s American Community Survey (ACS). The most recent ACS is for 2024.
The estimates reflect the growing diversification of the U.S. unauthorized immigrant population, due to the widening array of nationalities arriving at the U.S.-Mexico border over the past several years from within and beyond this hemisphere. The Mexican share of the unauthorized immigrant population was 35 percent as of 2024—a sharp decline from the 62 percent share in 2010 and 49 percent in 2019.