Which U.S. states had the largest undocumented immigrant populations in 2025?
Executive summary
By mid‑decade the consensus across major researchers was clear: the largest concentrations of undocumented (unauthorized) immigrants remain in a small set of large states — led by California and Texas and followed by Florida, New York, New Jersey and Illinois — though totals and rankings vary by methodology and year (notably most published state breakdowns use 2023 or earlier data) [1] [2] [3]. Analysts caution that state counts in 2025 rest on different estimation techniques (Pew, Center for Migration Studies, Migration Policy Institute) and on incomplete post‑2023 data, so headline rankings are stable but exact numbers are uncertain [4] [5] [6].
1. The headline list: which states top the charts
Multiple prominent reports identify the same six states as hosting the largest undocumented populations: California, Texas, Florida, New York, New Jersey and Illinois, which together accounted for the bulk of unauthorized residents in recent national estimates [1] [4]. Pew’s recent national work and summaries by outlets such as Axios put these six states at the center of the pattern, noting they held nearly eight million unauthorized immigrants as of 2023 estimates — a majority of the national total [1].
2. How big are the top states — approximate magnitudes
California remains the single state with the largest undocumented population even as its share of the national total has declined; state analyses say California’s undocumented share fell from an earlier 23 percent to about 16 percent, while Texas is a close second with roughly 2.05 million residents estimated in one recent analysis and Florida has seen the largest recent increases, rising from about 0.9 million in 2021 to roughly 1.6 million by 2023 [2]. Nationally, leading centers of research reported mid‑2023 unauthorized populations in the range of roughly 13.7–14 million, providing the context in which the state rankings are measured [7] [4].
3. Methodology matters: why numbers differ across sources
Estimates differ because groups use different data, adjustments and time frames: the Immigration Research Initiative and state tables compile multiple state estimates and note three distinct undocumented estimates from the Center for Migration Studies, Pew and Migration Policy Institute based on differing base years and adjustments for Census undercount [3]. The Center for Migration Studies and Migration Policy use statistical adjustments to ACS and CPS microdata to account for undercount, while Pew’s national reconstructions for 2023 blend survey and administrative signals; those choices change state totals and ranks [5] [6].
4. Recent dynamics that reshaped the map through 2023–25
Researchers say the unauthorized population grew sharply between 2021 and 2023, driven by border dynamics and parole programs, and that much of the population increase since then concentrated beyond the traditional gateway states — hence growth in Florida and inland parts of Texas — producing a more dispersed distribution across states by 2023 [4] [1]. Subsequent policy shifts and incomplete 2024–2025 data make projecting precise 2025 state totals difficult; Pew and MPI caution that policy changes and increased removals affected numbers after mid‑2024 [4] [6].
5. Limits, disagreements, and why precision is elusive
No single “official” year‑end 2025 state tally exists: DHS homeland statistics provide residence‑by‑state snapshots only through 2022 in their public series, and most analytic groups warn their state tables rely on earlier survey windows plus adjustments for undercounts, producing a range rather than a single figure [8] [3]. Analysts explicitly note that methods can even yield state undocumented estimates that differ meaningfully from noncitizen counts reported in the ACS because of undercount adjustments [3] [9].
6. Bottom line for 2025 reporting
The best available, contemporaneous reporting and research identify California, Texas, Florida, New York, New Jersey and Illinois as the states with the largest undocumented populations in the period spanning 2023–25, with California and Texas leading and Florida rising rapidly — but exact 2025 headcounts depend on which research team’s methodology is used and on incomplete post‑2023 data [1] [2] [4].