N-400 naturalization: eligibility, documents, interview, and risks.

Start with the correct naturalization basis

The usual N-400 path is based on at least five years as a lawful permanent resident. A separate three-year path may apply to an applicant who has been a permanent resident for at least three years and has lived in marital union with the same U.S. citizen spouse during the required period and while USCIS adjudicates the application. Military service and certain spouses employed abroad can involve different rules. The eligibility basis controls the residence period, physical-presence calculation, good-moral-character period, and supporting documents.

The common five-year rule

Under the common five-year path, an applicant generally must be at least 18 when filing; have been lawfully admitted as a permanent resident for at least five years; maintain five years of continuous residence; be physically present in the United States for at least 30 months; and live for at least three months in the state or USCIS district with jurisdiction. The applicant must also establish good moral character, attachment to constitutional principles, English and civics ability unless an exception applies, and willingness and ability to take the Oath of Allegiance.

• At least five years as a lawful permanent resident
• At least 30 months—913 days—of physical presence during the five-year statutory period
• At least three months of residence in the relevant state or USCIS district
• Continuous residence through filing and naturalization
• Good moral character through the oath ceremony

The three-year spouse-of-a-U.S.-citizen rule

A qualifying applicant may use a three-year period under INA 319(a). USCIS requires at least three years as a permanent resident, marital union with the U.S. citizen spouse during the three years before filing and while the case is decided, three years of continuous residence, and at least 18 months of physical presence. Divorce, separation, the spouse's loss of citizenship, or uncertainty about when the spouse became a citizen can affect this basis. When the three-year requirements are not met, the applicant may need to wait for the five-year path.

• At least three years as a lawful permanent resident
• Living in marital union with the qualifying U.S. citizen spouse
• At least 18 months of physical presence during the three-year period
• Three months of residence in the filing state or USCIS district
• Continued qualification through adjudication and the oath

Continuous residence and physical presence are different

Physical presence counts the days actually spent in the United States. Continuous residence asks whether the United States remained the applicant's principal actual dwelling place. A trip of more than six months but less than one year creates a presumption that continuous residence was broken unless the applicant proves otherwise. An absence of one year or more generally breaks continuous residence, subject to limited statutory exceptions. Multiple shorter trips can also draw scrutiny when they suggest the applicant's actual home was abroad.

• Create a complete trip list using passports, travel records, tickets, and calendar records
• Reconcile every trip with the N-400 and prior immigration forms
• For a trip over six months, gather tax, home, employment, banking, and family evidence
• Review any reentry permit or Form N-470 history without assuming it resolves naturalization residence

Good moral character requires a full history review

USCIS reviews good moral character during the applicable statutory period and may consider earlier conduct when relevant. Arrests, citations, convictions, probation, diversion, taxes, child support, false testimony, selective-service issues, and other unlawful acts can matter. A sealed, expunged, dismissed, or old case should not simply be omitted. USCIS's N-400 checklist asks for records in several of these situations, and the immigration effect of a criminal matter is not determined only by how a state court labels the result.

Review the green-card and immigration history before filing

Naturalization gives USCIS another opportunity to review how permanent residence was obtained and whether later conduct affected that status. The N-400 should be checked against prior petitions, adjustment or consular filings, border encounters, removal proceedings, marriage history, employment records, and any claim to U.S. citizenship or voter registration. A discrepancy does not always mean ineligibility, but guessing or filing around it can create avoidable risk.

Documents to organize before preparing Form N-400

The exact evidence depends on the eligibility basis and personal history. USCIS generally expects a copy of both sides of the green card and may require marital, travel, tax, criminal, support, selective-service, or name-change records. Foreign-language documents need a complete English translation with the translator's certification. Keep the form, evidence, and interview answers consistent.

• Green card, passports, and complete travel history
• Current and prior marriage, divorce, annulment, or death records
• Tax transcripts and records for payment arrangements when taxes are owed
• Certified court dispositions, arrest reports, sentencing, probation, and completion records where applicable
• Child-support, selective-service, name-change, and disability-exception documents where relevant
• Copies of prior immigration filings and notices

Filing online, by mail, or up to 90 days early

USCIS generally allows Form N-400 to be filed online or on paper. Applicants requesting a reduced fee or fee waiver must file on paper with the applicable request and evidence. USCIS lists the current N-400 edition as 01/20/25. Applicants using the five-year basis or qualifying three-year spouse basis may file up to 90 calendar days before completing the continuous-residence period, but the rule does not move every other requirement forward. Filing even one day too early can cause a denial.

What happens at the naturalization interview

A USCIS officer reviews the N-400 and asks about the applicant's background, residence, travel, family, work, taxes, and eligibility. Unless an exception applies, the officer evaluates spoken English during the interview and administers reading, writing, and civics tests. Applicants receive two opportunities to pass each required test portion; a failed portion is generally retested between 60 and 90 days after the initial interview. The officer may approve, continue, or deny the case depending on the record.

The current English and civics requirements

For English, the applicant's speaking ability is evaluated during the interview, and the applicant must correctly read one of three sentences and write one of three sentences. The civics version depends on the N-400 filing date. Applications filed before October 20, 2025 use the 2008 oral test, with up to 10 questions from 100 and 6 correct answers required. Applications filed on or after that date use the 2025 oral test, with 20 questions from 128 and 12 correct answers required. Age-and-residence exemptions and Form N-648 may change these requirements.

Common N-400 problems to address before filing

Problems often arise when an applicant estimates travel dates, omits a minor arrest, relies on an incorrect three-year marriage basis, files too early, fails to disclose taxes or support obligations, or assumes citizenship testing is the only issue. A strong naturalization case is accurate, internally consistent, and supported where the history requires documentation. Reviewing the complete record before filing is usually safer than trying to explain a surprise at the interview.