How has the number of undocumented immigrants in the U.S. changed since 2010 and what drove those trends?
Executive summary
Since 2010 the best-available estimates show the U.S. undocumented (unauthorized) population was roughly stable to slightly down in the 2010s, rose again after 2020, and by mid‑2023 many researchers put the total in the 11–14 million range depending on method—CMS estimated 11.7 million in July 2023 while Migration Policy Institute and others report figures near 13–14 million for 2023 [1] [2] [3]. Drivers cited across analyses include falling net growth in the 2010s (lower crossings, more departures and naturalizations), then sharp increases in border arrivals and parole entries after 2020, plus changes in origin-country composition and measurement methods [4] [5] [6].
1. A decade of stability then a recent upswing — the headline numbers
Multiple respected estimates show a largely stable or modestly declining undocumented population through much of the 2010s and then growth in the early 2020s: Center for Migration Studies (CMS) reported the population rose to about 11.7 million by July 2023 [1], Migration Policy Institute (MPI) described 13.7 million unauthorized immigrants by mid‑2023 [2], and other compilations document an increase in arrivals and border activity after 2020 that drove much of the uptick [5]. Different methodologies and provisional data make precise totals contested, which is why short-term year‑to‑year comparisons vary [1] [2].
2. Why numbers look different across sources — methodology matters
Estimates diverge because researchers use different approaches: the residual method subtracts legal foreign‑born counts from total foreign‑born counts (used historically by DHS, Pew and others), while some newer CMS and MPI work use Census and CPS adjustments and different assumptions about emigration, deaths, visa overstays and naturalizations [7] [1]. The Social Security Administration review and other methodological critiques note rising visa overstays and changing emigration patterns complicate post‑2010 measurement [7].
3. What drove the long 2010s slowdown — fewer net additions
Analysts say the 2010s saw much lower net growth because arrivals were offset by departures, deaths, and legal status adjustments. MPI quantified that roughly 5.9 million people entered (illegal crossing or overstay) in 2010–2019 while about 5.7 million left the undocumented population via emigration, death, or legalization—producing a near‑zero net change over that decade [5]. DHS data reviewed by others also indicate smaller per‑year increases in the early 2010s compared with the 2000s [4].
4. The post‑2020 bounce — border arrivals, parole programs, and policy shifts
Researchers attribute much of the early‑2020s growth to surges at the U.S.-Mexico border, expanded use of parole and humanitarian admissions, and broader migration pressures. MPI and CMS link increased arrivals after 2020 to record border encounters and large numbers paroled or otherwise admitted, which raised the unauthorized population by hundreds of thousands in 2021–2023 [5] [1]. The American Immigration Council notes recent‑arrival counts fell between 2018–2020 and then rose substantially from 2020–2022, reflecting this shift [8].
5. Origin shifts: Mexico’s share fell; diversity rose
A consistent finding across recent analyses is a change in country of origin: Mexico’s share of the unauthorized population has declined sharply from about 62% in 2010 to roughly 40% by the early 2020s, meaning growth has come from a wider set of countries [6] [2]. That diversification influences where people settle, employment patterns, and how enforcement and legal pathways affect totals.
6. Political and policy influences — enforcement, parole, and administrative choices
Observers emphasize policy choices (enforcement intensity, asylum processing, parole programs, and choices around removals or work authorization) materially affect measured population size. Pew and other groups note that administrative decisions in 2024–2025 (stopping some asylum/parole channels and revoking temporary protections) slowed growth late in 2024 and into 2025, and may have prompted declines in 2025 according to provisional signals [3] [9]. Available sources do not mention every specific policy change beyond the examples they cite.
7. Limits, disputes, and what to watch next
Estimates remain imprecise: different teams produce totals from about 11 million to over 13 million for 2022–2023 because of methodological choices and lagging data [1] [2]. Some groups (not in the provided sources) publish much higher or lower figures; those are not covered here—available sources do not mention alternative outlier estimates beyond the cited CMS, MPI and Pew work. Key near‑term indicators to watch are DHS border encounter data, CPS/ACS foreign‑born totals, and how future administrative policies affect asylum/parole flows [5] [9].
Bottom line: researchers agree the story since 2010 is not a simple continuous rise — the 2010s were relatively flat due to offsetting exits, while the early 2020s saw notable growth driven by border and parole arrivals and changing origin patterns. Disagreement centers on exact totals and on how to model departures, overstays and temporary protections [5] [1] [7].