How many illegals came in the U.S. during the Biden administration
Executive summary
Estimates vary depending on the measure: "encounters" at the border number in the millions (for example, roughly 7.2 million southern‑border encounters from Feb. 2021–Sept. 2024) while government processing produced roughly 2.5 million releases and about 2.8 million removals/expulsions in an earlier government accounting, and independent analysts estimate a net undocumented population increase in the Biden years of roughly 5.5–6 million — far below repeated political claims of 20–30 million new arrivals [1] [2] [3] [4]. All these figures depend on definitions (encounters vs. people vs. net population), repeat crossers, parole programs and visa overstays, and thus no single headline number captures the full reality [5] [6].
1. What proponents mean by “how many came” — encounters, admissions, or net additions
Political claims often conflate distinct measures: Customs and Border Protection (CBP) tallies "encounters" when migrants are caught or processed, which amounted to about 7.2 million between February 2021 and September 2024 in one widely cited count, but encounters can include repeat crossers and both unlawful crossings and scheduled lawful asylum appointments that still register as encounters [1] [5]. FactCheck and DHS reporting break those encounters into outcomes — in an aggregate government accounting, roughly 2.5 million people were released into the U.S. for further processing while some 2.8 million were removed or expelled in initial processing, illustrating how "encounter" does not equal a permanent new resident [2].
2. Net change in the undocumented population — what demographers estimate
Demographers and policy analysts use residual methods and administrative signals to estimate population change rather than raw Border Patrol counts; the Cato Institute and similar analyses have concluded the undocumented population rose by roughly 5.5–6 million during the Biden administration, a substantive increase but far short of 20–30 million claims [3]. Pew Research reported the unauthorized‑resident population reached a record 14 million in 2023, noting growth tied both to new entries and to parole programs and temporary protections that let some arrive lawfully for a period — again demonstrating the difference between people newly encountered at the border and the stock of unauthorized residents [7].
3. Enforcement and returns — millions repatriated or expelled
Enforcement actions during the period were also large: Migration Policy has counted nearly 4.4 million repatriations (deportations, expulsions and returns) under Biden — a figure that complicates simple additive claims because many migrants were returned rather than staying [8]. The Center for Migration Studies and DHS noted that more than 4 million encountered migrants were returned in some period and that 20–25% of encounters are repeat crossers, which reduces the count of unique individuals who “came and stayed” [6].
4. Where the 20–30 million claims come from — and why they are unreliable
High political estimates — including statements by partisan commentators and politicians — have asserted that 20–30 million people entered under Biden, but multiple fact‑checks and demographers have called those figures exaggerations; Newsweek, The Fulcrum and others documented that such totals misread encounters, ignore removals and repeats, and count hypothetical long‑term population shifts rather than measured arrivals [4] [9]. Congressional witness claims and partisan fact sheets sometimes produce alternative totals (for example, a witness document asserting 6.7 million new inadmissible residents), underscoring that source intent (advocacy vs. neutral scholarship) matters when interpreting headline numbers [10].
5. Key limitations and why absolute precision is impossible
Public data have unavoidable limits: "encounters" double‑count frequent crossers, parole programs admitted lawful temporary entrants who are not "illegal" in the same sense, and visa overstays — estimated to be a large share of unauthorized residents — are not captured by border encounter tallies, so any single figure will mask complexity [6] [7] [5]. Analysts therefore present ranges and net‑change estimates rather than a simple total; the best synthesis of available reporting is that millions more unauthorized residents were present by mid‑2020s (estimates around 5.5–6 million net increase), while cumulative encounters and enforcement actions each number in the low‑to‑mid millions depending on the period and definition used [3] [2] [8].