Denaturalization: Revocation of Naturalization (INA §340)

TL;DR

Denaturalization is the legal process of REVOKING a person's US citizenship after it was granted through naturalization. The governing statute is INA §340 (codified at 8 U.S.C. §1451). Civil denaturalization under §340(a) rests on two grounds: (1) that naturalization was ILLEGALLY PROCURED — meaning the person did not actually meet a statutory requirement for naturalization (for example, was not lawfully admitted for permanent residence, lacked the required good moral character, or gave false testimony); or (2) that naturalization was procured by CONCEALMENT OF A MATERIAL FACT OR BY WILLFUL MISREPRESENTATION. For the misrepresentation ground, the Supreme Court's decision in Kungys v. United States sets a four-part test: the person misrepresented or concealed a fact, did so willfully, the fact was material (it had a natural tendency to influence the naturalization decision), and citizenship was procured as a result. The government must prove its case by CLEAR, UNEQUIVOCAL, AND CONVINCING evidence — a higher standard than the ordinary civil "preponderance." If the court finds the person liable on any ground, the INA requires the court to REVOKE the naturalization; the court has no discretion to let it stand. Separately, denaturalization can also follow a CRIMINAL conviction under 18 U.S.C. §1425 (knowingly procuring naturalization contrary to law), which carries potential imprisonment and revocation upon conviction. Denaturalization is rare and reserved for cases involving fraud or ineligibility, but its consequences are severe — the person reverts to their prior immigration status and may face removal.

What denaturalization is

Naturalization is the process by which a lawful permanent resident becomes a US citizen. DENATURALIZATION is the reverse: a federal court order stripping a naturalized citizen of that citizenship. It applies only to NATURALIZED citizens — a person who acquired citizenship by birth in the United States cannot be denaturalized, because their citizenship did not come through the naturalization process that denaturalization unwinds. Denaturalization does not simply penalize post-naturalization conduct; it rests on the premise that the citizenship should never have been granted in the first place, because it was obtained illegally or through fraud.

The governing statute is INA §340, codified at 8 U.S.C. §1451. Because denaturalization reaches something as fundamental as citizenship, the courts have surrounded it with significant procedural protections — most importantly a heightened burden of proof on the government. For the requirement that a naturalization applicant possess good moral character (a frequent denaturalization issue), see our guide to good moral character standards.

The two grounds for civil denaturalization

Civil denaturalization under §340(a) proceeds on either or both of two grounds. A single valid ground is enough to require revocation.

Ground 1 — Illegally procured naturalization. Naturalization is "illegally procured" when the person did not actually meet one or more of the statutory requirements for naturalization at the time it was granted. Because every naturalization requirement is mandatory, failing to meet any one of them means the citizenship was granted contrary to law. Common examples include: the person was never lawfully admitted for permanent residence (so the underlying green card was invalid); the person did not meet the continuous-residence or physical-presence requirements; the person lacked the required good moral character during the statutory period; or the person gave false testimony to obtain an immigration benefit. Under this ground, the government does not have to prove the person intended to deceive — it only has to prove that a statutory requirement was not, in fact, met.

Ground 2 — Concealment of a material fact or willful misrepresentation. This ground targets fraud in the naturalization process. It applies when the person procured citizenship by concealing a material fact or by willfully misrepresenting something to immigration authorities. Importantly, the misrepresentation need not have occurred only during the naturalization application or interview — a material misrepresentation made during an earlier step that contributed to citizenship (such as obtaining the underlying visa or green card) can also support denaturalization on this ground.

The Kungys four-part test for misrepresentation

For the concealment/misrepresentation ground, the Supreme Court's decision in Kungys v. United States established that the government must prove four elements:

1 — Misrepresentation or concealment. The person misrepresented or concealed some fact.

2 — Willfulness. The misrepresentation or concealment was willful — that is, deliberate and voluntary, not an innocent mistake.

3 — Materiality. The fact was material, meaning it had a NATURAL TENDENCY TO INFLUENCE the decision to grant naturalization. A trivial or irrelevant misstatement that could not have affected the outcome is not material.

4 — Procurement. The person procured citizenship as a result of the misrepresentation or concealment — there must be a causal link between the fraud and the grant of citizenship.

All four elements must be established. The materiality requirement is a meaningful limit: not every false statement in a naturalization file will support denaturalization — only one that could have made a difference to the decision.

The government's burden of proof

Because citizenship is so consequential, the government's burden in a denaturalization case is HIGHER than in an ordinary civil lawsuit. The government must prove its case by CLEAR, UNEQUIVOCAL, AND CONVINCING evidence — a demanding standard that sits above the ordinary civil "preponderance of the evidence" (more likely than not). The Supreme Court has described the evidence needed to strip citizenship as needing to leave no issue in doubt. This heightened standard reflects the gravity of taking away citizenship and is one of the main procedural safeguards in the denaturalization process.

The other critical feature of §340(a) is that revocation is MANDATORY once a ground is proven. If the court finds the person liable on any ground — illegal procurement or misrepresentation — the INA requires the court to revoke the naturalization. The court does not weigh equities or exercise discretion to let the citizenship stand; the finding of liability compels the revocation. The safeguard is on the front end (the heightened burden of proof), not on the back end.

Civil versus criminal denaturalization

There are two distinct routes to denaturalization, and they should not be confused.

Civil denaturalization proceeds under INA §340(a) / 8 U.S.C. §1451(a) as a civil lawsuit filed by the government in federal district court. The remedy is revocation of citizenship. The government's burden is clear, unequivocal, and convincing evidence, and there is no jury and no criminal penalty — the outcome is loss of citizenship, not imprisonment.

Criminal denaturalization arises under 18 U.S.C. §1425, which makes it a crime to knowingly procure naturalization contrary to law. A conviction under §1425 is a criminal matter, prosecuted with the criminal standard of proof beyond a reasonable doubt, and it can carry imprisonment. Upon a §1425 conviction, revocation of citizenship follows as a consequence (under §1451(e)). The criminal route requires proof of knowing wrongdoing, whereas civil illegal-procurement does not require proof of intent.

Consequences of denaturalization

When a person is denaturalized, the effect is as if they had never naturalized. Their US citizenship is revoked, and they REVERT to the immigration status they held before naturalizing — typically lawful permanent resident, but potentially a status that is itself now removable if the underlying green card was also fraudulently or unlawfully obtained. A denaturalized person can therefore become subject to removal (deportation) proceedings, particularly where the same fraud that supported denaturalization also undermined their permanent-resident status. In covered situations, INA §340(d) can also affect a person who claimed citizenship through the naturalization of a parent or spouse whose naturalization is later revoked, although the precise effect depends on the statutory ground and the family member's facts.

Because the stakes are this high, denaturalization is used sparingly and is generally reserved for cases involving genuine fraud, concealment of serious matters, or clear statutory ineligibility. For how removal grounds interact with naturalization eligibility, see our guide to deportation and removal bars to naturalization.

Frequently Asked Questions

What is denaturalization?

Denaturalization is a federal court process that REVOKES the US citizenship of a naturalized citizen. It applies only to people who became citizens through naturalization — someone who is a citizen by birth cannot be denaturalized. The governing statute is INA §340 (8 U.S.C. §1451). It rests on the premise that the citizenship should never have been granted because it was obtained illegally or through fraud, and its consequences are severe, including possible removal after citizenship is lost.

What are the grounds for denaturalization?

Civil denaturalization under INA §340(a) has two grounds: (1) ILLEGAL PROCUREMENT — the person did not actually meet a statutory requirement for naturalization (such as lawful permanent residence, continuous residence, good moral character, or truthful testimony); or (2) CONCEALMENT OF A MATERIAL FACT OR WILLFUL MISREPRESENTATION — the person procured citizenship through fraud. A single valid ground is enough to require revocation. Denaturalization can also follow a criminal conviction under 18 U.S.C. §1425.

What is the Kungys test?

Kungys v. United States is the Supreme Court decision setting the four-part test for the misrepresentation ground of denaturalization: (1) the person misrepresented or concealed a fact; (2) the act was willful; (3) the fact was material — it had a natural tendency to influence the naturalization decision; and (4) the person procured citizenship as a result. All four must be proven. The materiality requirement matters: a trivial misstatement that could not have affected the decision does not support denaturalization.

How hard is it for the government to denaturalize someone?

The government faces a HEIGHTENED burden. It must prove its case by CLEAR, UNEQUIVOCAL, AND CONVINCING evidence — a standard higher than the ordinary civil "preponderance of the evidence." This reflects the gravity of stripping citizenship and is a key procedural safeguard. However, once a ground is proven to that standard, revocation is MANDATORY — the court has no discretion to let the citizenship stand, because the INA requires revocation upon a finding of liability.

What is the difference between civil and criminal denaturalization?

Civil denaturalization is a government lawsuit under INA §340(a) / 8 U.S.C. §1451(a); the burden is clear, unequivocal, and convincing evidence, and the remedy is revocation of citizenship with no imprisonment. Criminal denaturalization arises from a conviction under 18 U.S.C. §1425 (knowingly procuring naturalization contrary to law); it uses the criminal standard of proof beyond a reasonable doubt, can carry imprisonment, and revocation follows upon conviction. Civil illegal-procurement does not require proof of intent; the criminal route requires knowing wrongdoing.

What happens to a person after they are denaturalized?

After denaturalization, it is as if the person never naturalized: their citizenship is revoked and they revert to their prior immigration status, usually lawful permanent resident. If the same fraud also undermined that prior status, the person can become subject to removal (deportation) proceedings. Denaturalization of a parent can, in some fact-specific circumstances, affect status that flowed to family members. Because the consequences are severe, denaturalization is used sparingly and reserved for fraud or clear ineligibility.

Bottom Line

Denaturalization is the revocation of a naturalized person's US citizenship under INA §340 (8 U.S.C. §1451). Civil denaturalization under §340(a) rests on two grounds: ILLEGAL PROCUREMENT (a statutory naturalization requirement was not actually met — no intent required) and CONCEALMENT OF A MATERIAL FACT OR WILLFUL MISREPRESENTATION (fraud in the process). For the misrepresentation ground, the Kungys four-part test requires a willful misrepresentation or concealment of a MATERIAL fact — one with a natural tendency to influence the decision — that procured citizenship. The government's burden is CLEAR, UNEQUIVOCAL, AND CONVINCING evidence, higher than the ordinary civil standard; but once a ground is proven, revocation is MANDATORY. Denaturalization can also follow a criminal conviction under 18 U.S.C. §1425, which adds proof beyond a reasonable doubt and potential imprisonment. The consequences are severe: the person reverts to their prior immigration status and may face removal. It applies only to naturalized citizens and is used sparingly, reserved for genuine fraud or clear ineligibility. For related topics, see our guides to good moral character standards and deportation and removal bars to naturalization.

Source: 8 U.S.C. §1451 — Revocation of Naturalization (INA §340) · 18 U.S.C. §1425 — Procurement of Citizenship or Naturalization Unlawfully · USCIS Policy Manual, Volume 12, Part L — Revocation of Naturalization