Report Highlights Sharp Rise in Denaturalization Lawsuits

Lawsuits seeking to revoke U.S. citizenship have surged under the Trump administration, according to a new report. While the federal government historically filed fewer than one civil denaturalization case per month, the number rose sharply in May and June.

According to a June 17 report by TRAC, an immigration data research organization, the federal government filed at least 15 civil denaturalization lawsuits in May 2026 and 18 more by June 12. The figures mark a steep rise from a historical average of just 0.6 cases per month previously.

TRAC analyzed 166 denaturalization lawsuits filed in federal courts between 2008 and June 12, 2026. The report found that the main grounds for such lawsuits included use of false identities, immigration fraud, concealment of serious criminal conduct before naturalization, and false answers on naturalization applications.

One area of concern involves a question on the naturalization application asking whether an applicant has committed any criminal acts for which they were not arrested or convicted. A “no” answer to that question could be interpreted as false if the applicant received minor violations such as speeding, walking a dog without a leash, or fishing without a valid license. Under some jurisdictions such violations can be classified as crimes.

TRAC warned that the scope of denaturalization cases could expand in the future, adding the May and June 2026 lawsuits reviewed so far appear to be based on unlawful conduct serious enough to warrant civil denaturalization proceedings. Still, it said concerns are growing that less serious violations or even noncriminal conduct could be used as grounds for future lawsuits.

Operation Janus provided the foundation

The current expansion of denaturalization efforts has roots in Operation Janus, an initiative launched under the Obama administration in 2010. At the time, the government found that some immigrants who had been ordered deported or removed had later used different identities to obtain immigration benefits, prompting a review of older fingerprint records.

A 2011 search of Department of Homeland Security (DHS) databases found that about 315,000 people, including individuals with final deportation orders, criminal records or fugitive status, lacked digitized fingerprint records. DHS later began the Historical Fingerprint Enrollment, or HFE, project to digitize older paper fingerprint records.

Through that process, officials found that U.S. Citizenship and Immigration Services (USCIS) had naturalized about 858 people who had previously been ordered deported or removed under different identities. Their fingerprint records were not available in the electronic system at the time they became citizens.

USCIS later manually reviewed about 2,000 HFE-related naturalization cases. Of these, about 1,600 were found to involve individuals who allegedly concealed information and unlawfully obtained citizenship. As of May 2018, USCIS had referred 89 of those cases to the Justice Department for possible denaturalization.

Cases declined under Biden, resumed under Trump

Denaturalization lawsuits declined sharply after 2019, a drop attributed in part to the COVID-19 pandemic and reduced fee revenue at USCIS. During the Biden administration, the number of denaturalization cases remained low, averaging fewer than four per year.

That changed in June 2025, when the second Trump administration included denaturalization among its civil enforcement priorities. In a June 11, 2025, memo, the Justice Department’s Civil Division identified denaturalization as a key enforcement area. The memo also said the department could pursue “any other cases” it deemed sufficiently important and could take action outside the listed categories at its discretion.

TRAC said the language suggests not only that more denaturalization lawsuits are likely, but also that the range of conduct used to justify such cases could broaden.

Only eight denaturalization lawsuits were filed in all of 2025. But the number began rising sharply in May 2026. Some lawsuits filed in June alleged that USCIS fingerprint specialists determined, through fingerprint analysis, that the same individuals had previously applied for immigration benefits under different identities. TRAC said that suggests USCIS has resumed HFE reviews.

False identity, immigration fraud leading grounds

Among the 62 cases for which TRAC was able to identify the underlying basis, false identity and immigration fraud made up the largest category, with 14 cases overall. Six of those were filed in May and June 2026.

Other identified grounds included child molestation in five cases, fraud or misrepresentation in four, sexual abuse of a minor in three, narcotics distribution in two, terrorism in two, gun trafficking in two and Medicare fraud in two.

TRAC said the publicly available cases appear largely to involve serious crimes or clear misrepresentations. However, it noted that many actual complaints are not easily accessible through the online federal court records system, making it difficult to confirm the specific grounds in every case.

Legal basis may affect immigration status after citizenship loss

The statutes used can also determine whether someone who is denaturalized reverts to lawful permanent resident status or is left without immigration status and becomes subject to deportation or removal.

Denaturalization is governed under federal code 8 U.S.C. § 1451, and the most commonly used provision is § 1451(a) in cases where citizenship was deemed to have been “illegally procured.” TRAC found that about 66% of the 166 cases it analyzed were brought under that section.

Another commonly used provision is § 1451(h), which concerns the attorney general’s authority to correct, reopen, alter, modify or vacate a naturalization order.

An emerging immigration issue

TRAC said denaturalization, once rare in federal courts, is becoming more common. The resumption of HFE reviews, combined with the Justice Department’s decision to make denaturalization a civil enforcement priority, has created the administrative foundation for broader civil denaturalization efforts, the report noted.

“Denaturalization,” according to TRAC, is an emerging issue that requires continued monitoring. The organization said it plans to update its denaturalization database as new cases are filed and publish periodic findings.