How many undocument immigrants came into the country during Joe Biden's presidency?

1. Why the question is tricky: encounters, releases, removals and population estimates are different animals

Border “encounters” record interactions with U.S. authorities and are an event count rather than a headcount of distinct people who settled in the country, so summing encounters over a period will overstate the number who entered and stayed; analysts and fact-checkers caution against conflating encounter totals with the undocumented resident population ^{[4] [5]}. Government processing data show millions of encounters, but many encounters end in expulsions, removals or repeat encounters of the same person ^{[6] [1]}.

2. What government processing numbers show: millions of encounters, millions of removals, and about 2.5 million releases

FactCheck summarized U.S. government statistics showing that in initial processing millions of encounters yielded roughly 2.5 million people released into the U.S. and about 2.8 million removed or expelled through October of a recent year, illustrating the split between those released and those returned ^[1]. Congressional and DHS-related briefings record large annual encounter totals — for example, over 3.2 million encounters in FY2023 alone — but that is an encounters metric, not a settled-population tally ^[6].

3. What researchers estimate about the undocumented population’s net change

Scholarly and policy-oriented estimates focus on net population change rather than encounter counts: Cato’s analysis estimated a net increase in the undocumented population on the order of 5.5 to 6 million during the Biden era based on extrapolations from pre-2020 trends and demographic data, while Pew’s later analysis reported the unauthorized immigrant population reached a record 14 million in 2023 — up from widely cited pre-2021 estimates near 11 million — reflecting growth but not implying a 20-million influx during Biden’s term ^{[3] [7]}.

4. Where the 20 million figure comes from and why it’s unsupported

Political commentators and some elected officials have claimed that 20–30 million people entered illegally under Biden; fact-checkers and nonpartisan analysts have repeatedly rejected a literal reading of that claim because it typically conflates encounters, parole admissions, temporary parole programs, and net population changes into a single cumulative “entered” figure—an apples-to-oranges arithmetic that overstates what the underlying data support ^{[4] [5]}.

5. How to state the answer with precision given available sources

Using official processing data, roughly 2.5 million people were released into the U.S. in initial processing while about 2.8 million were returned or expelled ^[1]; using population-estimation methods, the unauthorized resident population increased by a few million during Biden’s term, with credible estimates clustering between roughly 3 and 6 million depending on methods and time windows ^{[3] [7] [2]}. Therefore, the best-supported answer is that millions entered or were released and the undocumented population rose by several million — but claims that tens of millions entered specifically during Biden’s presidency are not supported by the cited analyses ^{[4] [3] [1]}.

6. Sources, incentives and open questions worth noting

Official counts and administration or Congressional statements sometimes emphasize different metrics to advance policy narratives — enforcement-focused actors emphasize encounter totals and “gotaways,” while advocates highlight parole programs and humanitarian admissions — and this selective framing can inflate impressions of settled inflows; independent research groups and fact-checkers repeatedly warn about that framing problem, and the underlying questions of repeat encounters, parolees’ legal status, and later removals mean the exact “how many entered” number cannot be pinned down with a single definitive figure from the available reporting ^{[8] [9] [10]}.