A new report from the Federation for American Immigration Reform (FAIR) estimates that the number of illegal immigrants in the U.S. has surged past 18.6 million, marking an 11% increase in under two years and a total increase of over 4 million since the end of 2020.
The group, which advocates for reduced immigration, attributes the rise to the Biden administration’s border and immigration policies, including expanded use of humanitarian parole and the CBP One app, which allowed migrants to schedule border crossings.
“As of 2025, America’s population growth is driven almost entirely by unsustainably high levels of immigration — both legal and illegal,” the report states.
Biden-Era Policies Blamed for Surge
FAIR criticizes the Biden administration’s strategy of allowing migrants into the U.S. through parole programs and appointment-based entry as a workaround to formal immigration procedures. Although these migrants may be granted “lawful presence,” the group maintains they do not have legal status and should be counted as illegal immigrants.
“Labeling these individuals as ‘legal’ is a misrepresentation of immigration law,” the report argues.
The organization includes people in Temporary Protected Status or parole as part of its illegal immigrant estimate, claiming these policies were overused as a means to avoid formal removal.
In 2023, FAIR had estimated the number of illegal immigrants at 16.8 million. By March 2025, that number had climbed to 18.6 million, with a 28% increase since December 2020.
Border Policies Reversed Under Trump
The report comes amid a dramatic shift in immigration enforcement under President Donald Trump, who re-entered office in January and immediately declared a national emergency, ordered the military to the border, and revoked Biden-era parole and CBP One policies.
“Within hours of taking the oath, I declared a national emergency at the southern border and deployed our military and Border Patrol,” Trump said this week. “Illegal crossings last month were the lowest ever recorded. They heard my words, and they chose not to come.”
According to official data, border encounters in February 2025 dropped to 8,326, down sharply from 189,913 during the same month a year earlier under the Biden administration.
The Trump administration has also launched an interior enforcement campaign, resulting in over 55,000 deportations in its first two months.
FAIR: Data Still an Estimate
While asserting the spike in illegal immigration, FAIR acknowledged the limitations of its data, citing undercounts in Census figures and the difficulty in tracking “gotaways” and visa overstays. The group estimates the government may be undercounting the illegal population by as much as 40%.
“In truth, we don’t know exactly how many are here illegally — only estimates based on available data,” the report concedes.
Despite the uncertainty, FAIR maintains that the surge was fueled by what it calls a combination of “border mismanagement,” “abuse of parole authority,” and “policy loopholes” under the previous administration.
The Biden White House has not yet responded to the report.
