What is the estimated number of illegal aliens by state
Executive summary
Estimates of the number of "illegal aliens" (unauthorized or undocumented immigrants) living in each U.S. state vary significantly depending on methodology and data vintage: major analytic centers publish divergent national totals—roughly 11.0 million (DHS/Census-derived 2022 figure), 11.7–12.2 million (Center for Migration Studies variants), and 14 million (Pew’s 2023 estimate)—and each of those efforts also produces state-by-state breakdowns that do not perfectly align [1] [2] [3] [4]. For practical reporting, researchers and policymakers rely on side-by-side state tables compiled by neutral trackers like the Immigration Research Initiative that present CMS, Pew and MPI state estimates so readers can see the range for every state [5].
1. Why state estimates differ: methods and timing matter
State tallies of undocumented residents are produced using different inputs—American Community Survey weights, residual estimation techniques, adjustments for undercount, and varying time windows—so the number attributed to any state reflects methodological choices as much as geography; the residual estimation method and its critiques are a central part of this measurement debate [6] [5].
2. Where to find state-by-state numbers right now
A convenient, comparative resource that lays out three major state estimates (Center for Migration Studies, Pew Research Center, and Migration Policy Institute) is the Immigration Research Initiative’s "50 States: Immigrants by Number and Share" table, which explicitly shows the three different undocumented counts by state and explains the methodological caveats [5]. The Department of Homeland Security’s Office of Homeland Security Statistics also maintains residence-state estimates across fiscal years that are widely used for enforcement and planning purposes [7].
3. The big-picture geographic pattern: concentrated but spreading
Although the unauthorized population historically concentrated in a few states, recent analyses show diffusion: Pew reports that in 2023 the top six states contained 56 percent of unauthorized immigrants, down from 80 percent in 1990, signaling wider dispersion across states even as absolute numbers rose in their estimates [4]. Visual summaries and maps corroborate the concentration pattern while offering state-level visuals for quick comparison [8].
4. National totals set the frame, but states show the range
Different national totals feed into differing state lists: DHS-linked analyses and bodies cited by advocacy groups reported about 11.0 million undocumented immigrants as of 2022 [1], CMS and related academic updates presented higher provisional counts in the 11.7–12.2 million range for 2023 [2] [3], and Pew produced a 14 million estimate for July 2023 using ACS-based methods [4]. Nongovernmental organizations that favor stricter immigration controls sometimes produce much higher figures—FAIR, for example, reported an 18.6 million estimate for 2025—which highlights how political aims can shape framing and selection of inputs [9].
5. How to interpret a state number in context
A single "best" number by state does not exist; the responsible approach is to present a range and note the underlying source and year. The Immigration Research Initiative’s side‑by‑side state table is designed for that purpose, letting readers see a low, medium and high estimate per state drawn from CMS, Pew and MPI so the uncertainty is explicit [5]. DHS residence-state series can be used for trend analysis tied to enforcement reporting, but it reflects a different construct than ACS‑based residual estimates [7] [6].
6. Practical takeaway for reporters and policymakers
Cite the specific source and year when quoting a state total, show a comparator (other estimates for the same state), and flag methodological caveats—these are standard practices because measurement choices change both national totals and state allocations; primary reference points include the Immigration Research Initiative table for crosswalks [5], DHS OHSS datasets for enforcement-oriented residence data [7], and the major analytic centers (Pew, CMS, MPI) for interpretive estimates [4] [3] [10].