What Is the N-400 Form?

Form N-400, the Application for Naturalization, is the official document submitted to U.S. Citizenship and Immigration Services (USCIS) by eligible lawful permanent residents (green card holders) who want to become United States citizens. Filing the N-400 initiates the naturalization process — the legal pathway through which a foreign national officially becomes a U.S. citizen with full rights including the right to vote, hold a U.S. passport, and sponsor family members for immigration.

The N-400 is a comprehensive application that collects detailed information about the applicant's identity, immigration history, continuous residence in the United States, employment history, travel history, marital status, and character. USCIS uses the information on the form — along with biometric data, a background check, a civics test, and an in-person interview — to determine whether the applicant meets all statutory requirements for naturalization.

Most applicants must be at least 18 years old and must have held lawful permanent resident status (a green card) for a qualifying period — typically five years, or three years if married to and living with a U.S. citizen. There are limited exceptions for certain military service members and their families, as well as for children of U.S. citizens in specific circumstances. For most applicants pursuing the standard citizenship path, the N-400 marks the beginning of the final stage of a long immigration journey.

The N-400 is filed with USCIS either online through the USCIS online account portal or by mail with a paper application. The current filing fee is $760 for online filers and $725 for paper filers (as of the April 2024 fee schedule). Fee waivers are available for applicants who demonstrate financial hardship. Certain applicants over 75 years of age may also be eligible for an exemption from the biometrics fee, and long-term residents over 50 may qualify for an exemption from the English language test requirement.

Who Is Eligible to File the N-400?

Eligibility for naturalization through the N-400 is governed by the Immigration and Nationality Act (INA). The most common eligibility path requires that you be a lawful permanent resident of the United States for at least five continuous years immediately before filing. Continuous residence means you've maintained your U.S. domicile and haven't abandoned your green card status during that period.

Physical presence is a separate and distinct requirement from continuous residence. You must have been physically present in the United States for at least half of the required residence period — 30 months of the 60-month period for standard applicants, or 18 months of the 36-month period for those qualifying through marriage to a U.S. citizen. Lengthy absences from the United States — particularly single trips of 6 months or more — can disrupt continuous residence and reset your eligibility clock.

Applicants who obtained their green card through marriage to a U.S. citizen and who have remained married to and living with that spouse throughout the required period qualify for the reduced three-year timeline. This path requires the U.S. citizen spouse to have been a citizen for the entire three-year period, not just at the time of filing. Both spouses must have maintained the same marital domicile continuously.

Members of the U.S. armed forces who have served honorably may qualify for naturalization under a separate, expedited pathway with reduced or waived residence and physical presence requirements. Some who served during designated periods of hostility may qualify for naturalization without any prior period of permanent residence at all. Surviving spouses of military members who died on active duty may also have access to simplified naturalization processes under separate statutes.

Good moral character is required throughout the statutory period and is assessed based on your N-400 disclosures, background check results, and any criminal history. Certain crimes — including aggravated felonies, most controlled substance offenses, and acts involving moral turpitude — can permanently bar or temporarily bar you from naturalization. The good moral character requirement extends from the statutory period back to any time USCIS considers relevant, so prior arrests or convictions from decades ago may be reviewed.

The N-400 Form: What It Asks

The N-400 application is a detailed 20-page form that covers the applicant's complete personal, immigration, and legal history. Understanding what the form asks — and the importance of answering every question honestly and completely — is essential before you begin filling it out.

The form collects basic identifying information: legal name, aliases, Social Security Number, Alien Registration Number (from your green card), date of birth, country of birth, and physical description. It then covers your current and prior addresses for the past five years, your employment history, your marital and family history, and whether you've ever registered to vote or claimed to be a U.S. citizen.

A significant portion of the N-400 is dedicated to character questions. These ask whether you've ever been arrested, cited, charged with, or convicted of any crime; whether you've ever been involved in terrorism, persecution, genocide, or torture; whether you've ever been a member of any organization including the Communist Party or any group advocating for the violent overthrow of the U.S. government; and other questions designed to assess whether you meet the statutory good moral character standard.

Answering "yes" to a character question doesn't automatically disqualify you from naturalization, but it does require explanation and documentation. Many USCIS adjudicators are accustomed to seeing minor traffic violations, misdemeanors, and even some felonies in applicant files — what matters is whether the specific offense falls within the statutory bars to naturalization. The worst outcome in the character section is a "no" answer to a question that should have been "yes" — USCIS treats inconsistencies between what you disclose and what their background check reveals very seriously.

The N-400 also includes a dedicated section on international travel, where you must list every trip outside the United States lasting 24 hours or more during the statutory period. You'll record the destination country, departure date, return date, and trip duration for each entry. This section matters because USCIS uses your travel history to calculate both continuous residence and physical presence — so accuracy here is essential, not optional.

Applicants with frequent international travel — those who work abroad, have family overseas, or traveled extensively — should compile a complete travel log from passport stamps, airline records, and bank statements before starting the form. USCIS cross-references declared travel history against Customs and Border Protection entry and exit records, so omissions or date errors are likely to surface during the background check phase and could require a Request for Evidence that delays your application by several months.

The N-400 Application Process: Step by Step

The naturalization process follows a predictable sequence of steps after you file your N-400, though the timeline at each stage varies significantly based on the USCIS field office that handles your case, your local biometrics appointment center workload, and any complexity in your individual application.

After USCIS receives your application, they'll mail you a receipt notice (Form I-797) confirming they have your N-400. This receipt notice is important — it confirms your filing date, which establishes your eligibility clock starting point and your place in the processing queue. Keep all USCIS correspondence carefully — losing these notices can complicate your case if questions arise later.

A biometrics appointment follows the receipt notice, typically within four to eight weeks. At the biometrics appointment, USCIS collects your fingerprints, photograph, and signature. These are used to conduct an FBI background check and to prepare your naturalization certificate if you're approved. The biometrics appointment is straightforward — you attend, provide your information, and leave. No preparation is required beyond bringing your appointment notice and valid government ID.

The naturalization interview is the most important step in the process. A USCIS officer reviews your N-400 answers with you, verifies your identity and eligibility, conducts your English language test, and administers the civics test. The interview typically lasts 15 to 30 minutes. Officers may request additional documents if anything in your file requires clarification, and complex cases involving criminal history or extended travel may require additional review periods after the interview before a decision is issued.

If your application is approved, you'll receive a notice for a naturalization ceremony — either a judicial ceremony or an administrative ceremony conducted by USCIS. At the ceremony, you take the Oath of Allegiance to the United States, receive your Certificate of Naturalization, and officially become a U.S. citizen. You can apply for a U.S. passport immediately after the ceremony using your Certificate of Naturalization as proof of citizenship.

Preparing for the N-400 Civics Test and Interview

Preparation for the N-400 interview has two components: civics test preparation and organizational preparation. Both matter, and neither should be left until the last minute.

For the civics test, USCIS publishes all 100 possible questions and their official answers on the USCIS website. You're allowed — and expected — to study from this list. The officer won't ask any question that isn't on the official list. Most applicants find that four to eight weeks of regular study is sufficient to memorize the questions and answers, particularly if they're already familiar with basic U.S. history and government from living and working in the United States. Flashcard applications, USCIS's own study tools, and practice tests modeled on the 100-question bank are all effective preparation methods.

For organizational preparation, compile all documents you'll need to bring to your interview well in advance. USCIS sends you an interview appointment notice that lists required documents — typically including your green card, your current passport, any travel records, your marriage certificate if applying through the 3-year pathway, and certified court dispositions for any criminal history you disclosed. Missing documents at the interview can result in a continuance, which adds months to your timeline.

Practice answering questions about your N-400 in English before your interview. The officer will ask you to confirm the information you provided on the form — your name, address, employment, marital status, and character questions. Being able to answer these questions clearly in English demonstrates both your language ability and your familiarity with your own application. Hesitation or confusion about information you submitted months ago can create unnecessary complications, even when the underlying facts are completely straightforward.

After the interview, USCIS issues one of three outcomes: approval, a continuance requiring additional review or documents, or a denial. Most straightforward applications are approved at the interview itself or shortly afterward. If additional review is needed — due to a pending name change, an unresolved background check item, or a missing document — USCIS will notify you by mail with instructions on what is required and the deadline to respond.

A denial triggers your right to a hearing before an immigration officer and ultimately to federal court review. Outright denials for qualified applicants who filed complete, honest applications are relatively uncommon, though they do occur in cases involving complex criminal histories or residence gaps. Tracking your case status online through the USCIS case status portal keeps you informed at every stage. Keeping your mailing address current in the USCIS system throughout the process ensures you receive every notice — missing a USCIS deadline can result in automatic denial even when the underlying application is strong.

N-400 Filing Fees and Fee Waivers

The N-400 filing fee includes two components: the base application fee and the biometrics service fee. For paper filers, the total is $725 ($640 base + $85 biometrics). For online filers, the total is $760 ($675 base + $85 biometrics). The online filing fee is slightly higher because USCIS charges a premium for online applications, though online filing offers faster processing in most cases.

Applicants aged 75 or older are exempt from the biometrics fee, reducing their total to $640 (paper) or $675 (online). The biometrics exemption for applicants 75 and older is automatic — no special request is required.

Fee waivers are available for applicants who demonstrate an inability to pay. USCIS evaluates fee waiver requests based on household income relative to federal poverty guidelines, means-tested benefit receipt (Medicaid, food stamps, SSI, TANF), or individual financial hardship circumstances. Submitting a strong fee waiver request requires documentation — bank statements, pay stubs, benefit award letters — and incomplete requests are typically denied without appeal. Fee waivers for the N-400 are submitted on Form I-912 concurrently with your N-400 application.

The current N-400 fee schedule took effect on April 1, 2024, representing the largest USCIS fee restructuring in over a decade. The 2024 rule introduced separate online and paper filing tiers and eliminated the reduced-fee option that previously existed for some lower-income applicants, making the fee waiver pathway via Form I-912 more important than ever for financially challenged applicants.

Nonprofit immigration legal aid organizations and accredited representatives often host free or reduced-cost naturalization clinics that include assistance with fee waiver applications. Many community organizations, libraries, and legal services offices provide this support at no charge to qualifying residents. Applicants who believe they may qualify for a fee waiver should locate these resources in their community before submitting the N-400 without a waiver — it is significantly easier to submit the I-912 with the original application than to seek a refund or reopen a case after the fact.