What Is the N-400 Form? Application for Naturalization

The N-400 form is the Application for Naturalization that lawful permanent residents file with U.S. Citizenship and Immigration Services (USCIS) to become U.S. citizens. Filing it triggers a review of your background, residency history, English ability, and knowledge of U.S. civics, and if you clear each step you take the Oath of Allegiance and receive a Certificate of Naturalization.¹ The form itself is straightforward. The eligibility details are where applicants get tripped up.

Who Can File

You must be at least 18 when you file. From there, eligibility splits into a few tracks:²

Five-year track. You’ve held a green card for at least five years, been physically present in the U.S. for at least 30 of those months, and lived in your USCIS district for at least three months.³
Three-year spouse track. You’ve held a green card for at least three years, been married to and living with the same U.S. citizen spouse that entire time, and been physically present for at least 18 months.⁴
Military service. Current or former members of the U.S. Armed Forces have a separate, faster path. One year of honorable peacetime service qualifies you under INA Section 328; during designated periods of hostility under INA Section 329, there is no minimum service duration. Military applicants pay no filing fee, and service members stationed overseas can complete the entire process abroad, including biometrics, interview, and oath.⁵

You can file up to 90 days before you technically meet the continuous residence requirement. On the five-year track, that means you can submit the N-400 once you’ve held your green card for four years and nine months.⁶ Many applicants wait longer than they need to because they assume the full period has to be up.

Continuous Residence and Time Abroad

Continuous residence does not mean you can never leave the country. The length of your trips is what matters, and USCIS looks at absences in three tiers:

Trips under six months generally raise no issue.
Trips of six months to one year create a legal presumption that continuous residence has been broken. You can rebut it with evidence of maintained employment, family ties, a home, and U.S. tax filings, but the burden is on you.⁷
Trips of one year or more break continuous residence. The clock generally resets, and you have to build the residency period again from scratch.

Keep detailed records of every departure and return. USCIS will audit your travel history against the residence requirements, and gaps in your dates are one of the most common causes of delay.

Good Moral Character

USCIS has to find that you’ve shown good moral character during the statutory period, which is usually the five years before filing, or three years on the spouse track. Officers weigh specific factors rather than making a general impression.³

Criminal history is the largest one. Some convictions permanently bar citizenship, including murder and aggravated felonies where the conviction came on or after November 29, 1990. Drug offenses, fraud, and any incarceration of 180 days or more during the statutory period can also block your application.⁸ Arrests that never led to conviction may still need to be disclosed, and you should collect certified court dispositions for each.

Financial obligations matter too. Failing to pay court-ordered child support, not filing tax returns, or owing significant back taxes can each undermine a good moral character finding. If you owe $2,500 or more in child support, the State Department can deny your passport even after you naturalize. Get current on these before you file and stay current through the whole process.

Male applicants who lived in the U.S. between ages 18 and 26 must show they registered with the Selective Service. Failing to register when required is treated as evidence against good moral character.⁹

What the Form Asks For

The N-400 wants a thorough accounting of the past five years. You’ll need exact dates and addresses for every place you’ve lived, every employer, and every trip outside the country during that period. You must attach photocopies of both sides of your Permanent Resident Card, plus supporting documents for any legal name change through marriage or court order. The form also asks about marital history, children, organizational memberships, and every encounter with law enforcement, including arrests, citations, and detentions where charges were dropped.

Download the current version of the form directly from the USCIS website. The agency updates it periodically, and an outdated edition will be rejected and returned.

Fees and Fee Waivers

The N-400 filing fee is $710 if you file online or $760 if you mail a paper application. As of April 2024, the biometrics fee is bundled into that amount, so there is no separate charge for fingerprinting.¹⁰

If cost is an issue, two options exist:

A reduced fee of $380 is available if your household income is at or below 400% of the Federal Poverty Guidelines. You must file on paper and include Form I-942.¹⁰
A full fee waiver is available if your household income is at or below 150% of the guidelines, or if you receive a means-tested benefit like Medicaid, SNAP, TANF, or SSI. File Form I-912 with supporting documentation.

Household income includes your spouse’s income if you live together, and dependents who rely on you financially. USCIS updates the Federal Poverty Guidelines annually on Form I-912P, so check the current version when you file.

Military applicants pay no fee for the N-400, and related applications like Form N-600 are also fee-exempt for them.¹¹

What Happens After You File

You can file online through a USCIS account or mail a paper application to the designated USCIS Lockbox. Online filing is $50 cheaper and lets you track your case in real time. After USCIS receives your application, it sends a Form I-797C, Notice of Action, with a receipt number. Keep it: it’s your proof of a pending application for employment and travel purposes.

As of early 2026, USCIS reports that 80% of N-400 applications are processed within roughly 5.5 to 9.5 months. Times vary a lot by field office. If you move while your case is pending, you must notify USCIS within 10 days using Form AR-11; missing that can cost you interview notices.

Once your application is accepted, USCIS schedules a biometrics appointment at an Application Support Center for fingerprints, a photograph, and a signature, which go to the FBI for a background check.¹² After it clears, you’re scheduled for a naturalization interview at a local field office, where an officer reviews your N-400 under oath and administers the two-part test:

The English test covers reading, writing, and speaking basic English. The reading and writing portions use simple sentences.
The civics test covers U.S. history and government. The officer asks 10 questions drawn from a study list, and you need at least 6 correct.¹³

Fail either portion and you’re not immediately denied. USCIS schedules a second attempt in 60 to 90 days, and only the section you failed is retested.¹⁴ Fail the retest and the application is denied; you’d file a new N-400 to try again.

Once you pass, USCIS schedules a naturalization ceremony where you take the Oath of Allegiance. Until you recite that oath you remain a permanent resident, so you can’t vote or hold a U.S. passport. At the ceremony you receive your Certificate of Naturalization, your primary proof of citizenship from then on.¹²

Test Exemptions and Disability Accommodations

Not everyone takes the full test. Age-based exemptions apply as follows:¹⁵

Age 50 or older with 20 years as a permanent resident: no English test; civics test in the language of your choice.
Age 55 or older with 15 years as a permanent resident: same exemption.
Age 65 or older with 20 years as a permanent resident: no English test, and a shorter civics test in your language.

Applicants with a physical or developmental disability, or a mental impairment lasting or expected to last at least 12 months, may qualify for a medical exception from both requirements. A licensed physician, osteopath, or clinical psychologist must complete Form N-648 and connect the diagnosis directly to the inability to learn or demonstrate the required knowledge.¹⁶ Vague or conclusory certifications get rejected regularly.

Separate from the medical exception, USCIS provides reasonable accommodations such as sign language interpreters, extra time, or Braille materials for applicants who still take the test. Request an accommodation on the N-400 or at any point in the process.¹⁷

If Your Application Is Denied

A denial is not the end. You have 30 days from the date you receive the denial notice to file Form N-336, Request for a Hearing on a Decision in Naturalization Proceedings. The filing fee is $700.¹⁸ A different officer, at the same grade level or higher than the one who denied you, conducts the hearing and can accept new evidence, examine you again, and either uphold or reverse the decision. USCIS must schedule the hearing within 180 days.

If the hearing also denies you, you can take the case to federal district court, but only after completing the N-336 process. You can also skip the appeal and file a new N-400, which sometimes makes more sense when the denial was based on a fixable issue like insufficient physical presence.¹⁸

Requesting Faster Processing

Premium processing is not available for the N-400. USCIS will guarantee an expedited review in one narrow situation: you receive Supplemental Security Income, those benefits will end within a year unless you become a citizen, and you applied at least four months ago. You’ll need a Social Security Administration letter showing the benefit expiration date.

Outside that scenario, USCIS may expedite at its discretion for serious financial loss, urgent humanitarian reasons, a government agency request based on national interest, or clear USCIS error on a prior application. Requests go through the USCIS Contact Center or your local field office, and approval is not guaranteed.

1
U.S. Citizenship and Immigration Services. Chapter 1 – Purpose and Background
2
USAGov. Become a U.S. Citizen Through Naturalization
3
Office of the Law Revision Counsel. 8 USC 1427 – Requirements of Naturalization
4
eCFR. 8 CFR Part 319 – Special Classes of Persons Who May Be Naturalized
5
U.S. Citizenship and Immigration Services. Chapter 5 – Application and Filing for Service Members INA 328 and 329
6
U.S. Citizenship and Immigration Services. Form N-400, Instructions for Application for Naturalization
7
U.S. Citizenship and Immigration Services. Effect of Breaks in Continuity of Residence on Eligibility
8
U.S. Citizenship and Immigration Services. Chapter 3 – Evidence and the Record
9
Selective Service System. USCIS Naturalization and SSS Registration Policy
10
U.S. Citizenship and Immigration Services. 2024 Final Fee Rule
11
Federal Register. U.S. Citizenship and Immigration Services Fee Schedule and Changes to Certain Other Immigration Benefit Request Requirements
12
U.S. Citizenship and Immigration Services. Naturalization – What to Expect
13
U.S. Citizenship and Immigration Services. Civics Flash Cards for the Naturalization Test
14
U.S. Citizenship and Immigration Services. Chapter 4 – Results of the Naturalization Examination
15
U.S. Citizenship and Immigration Services. Fact Sheet – Naturalization for Lawful Permanent Residents Age 50 and Over
16
U.S. Citizenship and Immigration Services. Chapter 3 – Medical Disability Exception Form N-648
17
U.S. Citizenship and Immigration Services. Chapter 1 – Purpose and Background
18
eCFR. 8 CFR Part 336 – Hearings on Denials of Applications for Naturalization