N-400 Eligibility Requirements Explained

Form N-400 is the application most permanent residents use to apply for naturalization. This page summarizes the two common residence-based paths. It does not decide whether any person is eligible; USCIS evaluates the complete application and individual facts.

General Five-Year Path

Under the general rule, the applicant must be at least 18 when filing and complete a five-year period as a lawful permanent resident. The 90-day early-filing provision may allow Form N-400 to be filed before the five-year continuous-residence anniversary, but it does not shorten the period that must be completed before naturalization.

• Continuous residence: Five years immediately before filing, subject to the early-filing rule, and continued residence in the United States from filing through naturalization.
• Physical presence: At least 30 months (913 days) in the United States during the five years immediately before filing.
• State or USCIS district: Generally at least three months of residence before filing.
• Good moral character: During the five-year statutory period before filing and through the Oath of Allegiance.

Three-Year Path for Certain Spouses of U.S. Citizens

A narrower rule may apply when an applicant has been a lawful permanent resident and lived in marital union with the same U.S. citizen spouse for the three years immediately before filing. The spouse must have been a U.S. citizen throughout those three years, and the marriage must continue through the oath. USCIS generally requires the spouses to actually live together in marital union through filing, subject to limited exceptions.

• Continuous residence: Three years immediately before filing, subject to the early-filing rule, and continued residence through naturalization.
• Physical presence: At least 18 months (548 days) in the United States during the three years immediately before filing.
• Good moral character: During the three-year statutory period before filing and through the oath.

Requirements for Both Paths

Applicants must also demonstrate basic English and knowledge of U.S. history and government unless an exception applies, show attachment to the principles of the Constitution, and be willing to take the Oath of Allegiance. Other requirements and exceptions may apply to an individual case.

When to Be Extra Careful Before Filing

Consider speaking with an immigration attorney or accredited representative if you have criminal history, complicated travel, unpaid taxes, prior immigration fraud concerns, removal history, or uncertainty about how you received your Green Card.

Frequently Asked Questions

Can I apply before my full residence period is over? Some applicants under the three-year or five-year path may file up to 90 calendar days before completing the required continuous-residence period. Every other eligibility requirement must be met when filing, and the full three or five years must be completed before naturalization.

Does eligibility guarantee approval? No. Filing means you are asking USCIS to review your case. The officer still reviews your application, evidence, interview answers, and background checks.