How to Apply for U.S. Citizenship by Naturalization With Form N-400

Who qualifies to file Form N-400?

Form N-400 is the USCIS application used by eligible lawful permanent residents and certain other qualifying applicants to seek U.S. citizenship through naturalization. The most common route is based on 5 years as a lawful permanent resident.

Under that route, an applicant generally must be at least 18 years old, maintain the required continuous residence, have at least 30 months of physical presence in the United States during the 5-year period, reside for at least 3 months in the relevant state or USCIS district, demonstrate good moral character, meet the English and civics requirements unless exempt, and be willing to take the Oath of Allegiance.

When the 3-year rule for spouses of U.S. citizens applies

Certain permanent residents can naturalize after 3 years rather than 5 under INA section 319(a). At filing, USCIS generally requires that you have been a lawful permanent resident for at least 3 years, have been legally married to and living in marital union with the same U.S. citizen spouse for at least 3 years, and that your spouse has been a U.S. citizen for at least 3 years.

The physical-presence requirement for this route is generally 18 months during the 3-year period. USCIS instructions also require qualifying applicants to remain legally married to the U.S. citizen spouse through the Oath of Allegiance.

Evidence commonly includes proof of the spouse's citizenship, the current marriage certificate, documents showing how any prior marriages ended, and evidence of marital union such as joint financial records, leases or mortgages, insurance records, children's records, and IRS tax transcripts.

You may be able to file up to 90 days early

If your eligibility is based on 5 years as a permanent resident or the qualifying 3-year marriage rule, USCIS permits filing Form N-400 up to 90 calendar days before you complete the required continuous-residence period.

This rule does not shorten other eligibility requirements that must already be satisfied when the application is filed. For example, a spouse applying under the 3-year rule must meet the applicable marriage requirements at filing. USCIS provides an Early Filing Calculator and warns that an application submitted before the permitted 90-day window may be rejected or denied.

Continuous residence is different from physical presence

Naturalization uses two separate residence concepts. Continuous residence concerns whether you maintained your U.S. residence over the required statutory period. Physical presence is the actual amount of time you were physically inside the United States.

Long trips abroad can affect naturalization eligibility. An absence of more than 6 months but less than 1 year may disrupt the required continuous residence unless the applicant establishes otherwise. An absence of 1 year or more generally breaks continuous residence unless a specific statutory preservation rule applies. Because travel history can materially affect eligibility, list trips accurately on Form N-400 and review long absences before filing.

What to gather before completing Form N-400

The exact documents depend on your case, but USCIS requires detailed information about your immigration and personal history. Prepare:

• Your Permanent Resident Card details and A-Number.
• Current and previous addresses for the period requested by Form N-400.
• Employment and school history.
• Dates of trips outside the United States.
• Current and prior marital information.
• Information about children.
• Tax-related information required by the form.
• Information and records concerning arrests, citations, charges or convictions when applicable.
• Evidence supporting any special naturalization category you claim.

If you need to replace an expired, lost or damaged Permanent Resident Card separately, see the Helpydo procedure on replacing or renewing a Green Card with Form I-90. That process is separate from naturalization.

How much Form N-400 costs in 2026

USCIS currently charges $710 for a general online N-400 filing and $760 for a general paper filing. There is no separate biometrics fee.

A reduced N-400 fee of $380 is available for qualifying applicants whose documented annual household income does not exceed 400% of the Federal Poverty Guidelines under the current USCIS fee schedule. A reduced-fee request must be submitted with a paper N-400 using the required application section and supporting documentation.

Certain applicants may qualify for a full fee waiver and must follow the paper filing procedure for that request. Applicants who qualify for naturalization based on military service under INA sections 328 or 329 pay $0.

File Form N-400 online or by mail

USCIS allows most applicants to file Form N-400 electronically through a USCIS online account. Online filing lets you complete the application, pay the fee electronically, upload evidence, receive case updates and respond to certain USCIS notices online.

Paper filing remains available. Use the current edition of Form N-400 and the filing address specified by USCIS for your delivery method and circumstances. Applicants requesting a fee waiver or the reduced N-400 fee cannot use the ordinary online filing route and must submit a paper application.

What happens after you file?

USCIS issues a receipt after accepting the application. The agency then performs required security and background checks and will notify you if it needs biometrics such as fingerprints, a photograph or signature.

If USCIS schedules biometrics, bring the appointment notice, your Permanent Resident Card and a second photo identification document such as a driver's license, passport or state-issued ID, following the instructions on the notice.

Keep your address current with USCIS while the case is pending. If you move, use the required USCIS change-of-address process; Helpydo has a separate guide on reporting a change of address to USCIS.

What to bring to your N-400 interview

USCIS schedules an in-person naturalization interview at the applicable field office. At a minimum, USCIS instructs applicants to bring:

• The naturalization interview appointment notice.
• Form I-551, Permanent Resident Card.
• A state-issued photo identification document, such as a driver's license.
• All valid and expired passports and travel documents that show your absences from the United States since becoming a permanent resident.
• Any additional evidence USCIS specifically requests or that is required for your eligibility category.

The USCIS officer reviews your Form N-400 and asks questions about your application and background. Speaking ability is evaluated during this interview unless an English-language exception applies.

How the English portion of the naturalization test works

Unless you qualify for an exception, naturalization applicants must demonstrate the ability to speak, read and write basic English. Speaking and understanding are assessed while the USCIS officer reviews your N-400. USCIS separately tests reading and writing using naturalization test material.

Applicants who are age 50 or older and have been lawful permanent residents for at least 20 years, or age 55 or older with at least 15 years as permanent residents, are exempt from the English requirement. They must still take the civics test, but may take it in their preferred language and must bring a qualified interpreter when required.

The 2025 civics test applies to new 2026 filings

USCIS changed the civics test for naturalization applications filed on or after October 20, 2025. Therefore, a new Form N-400 filed in 2026 uses the 2025 Naturalization Civics Test.

The current test is oral and draws from a bank of 128 civics questions. The officer asks up to 20 questions. You must answer at least 12 correctly to pass. The officer stops once you have answered 12 correctly or 9 incorrectly.

Some civics answers change after elections, appointments or statutory changes, so USCIS instructs applicants to give the name of the official serving at the time of the naturalization interview.

Exceptions to the English and civics requirements

The age-and-residence exceptions commonly called 50/20 and 55/15 waive the English-language requirement but not the civics requirement. Qualifying applicants may take civics in their preferred language.

Applicants who are at least 65 years old and have been lawful permanent residents for at least 20 years receive special civics consideration. Under the current test, USCIS uses 10 questions selected from a designated bank of 20, and the applicant must answer at least 6 correctly.

A person whose physical or developmental disability or mental impairment prevents compliance with the English or civics requirements may request a medical exception using Form N-648. A disability accommodation for an appointment is different from an N-648 testing exception.

You normally get a second opportunity on a failed test section

USCIS provides applicants two opportunities to meet the English and civics testing requirements for an N-400 application. If you fail a portion of the test at the first examination, USCIS generally retests only the failed portion at a second examination scheduled between 60 and 90 days after the initial examination.

USCIS can grant, continue or deny the application

After the examination, USCIS may grant the N-400, continue the case because additional evidence or testing is required, or deny the application. Federal naturalization law generally gives USCIS up to 120 days after the examination to make a decision.

If additional evidence is requested, follow the deadline and submission instructions in the USCIS notice. Missing an evidence deadline can affect the application.

You are not a U.S. citizen until you take the Oath

Approval of Form N-400 does not by itself complete naturalization. USCIS schedules an oath ceremony or, in some cases, may conduct one on the same day as the interview.

At the ceremony, USCIS reviews your responses to Form N-445, Notice of Naturalization Oath Ceremony, collects your Permanent Resident Card when required, and administers the Oath of Allegiance. Only after taking the oath do you become a U.S. citizen.

You then receive your Certificate of Naturalization. Review the certificate for accuracy before leaving the ceremony when possible and keep it in a secure location.

Common mistakes to avoid

• Filing more than 90 days before the permitted permanent-residence anniversary.
• Assuming the 90-day rule waives other eligibility requirements.
• Leaving out international trips or miscalculating continuous residence and physical presence.
• Using the 3-year spouse rule without meeting all marriage and marital-union requirements.
• Paying the wrong N-400 fee or attempting online filing when requesting a reduced fee or fee waiver.
• Failing to disclose required arrest, criminal, tax, marital or immigration information.
• Studying the old 2008 civics test for an N-400 filed on or after October 20, 2025.
• Missing a biometrics, interview or oath appointment without following USCIS rescheduling procedures.
• Failing to report an address change while the application is pending.