What Is Form N-400, Application for Naturalization?

Form N-400, Application for Naturalization, is the form lawful permanent residents file with U.S. Citizenship and Immigration Services to become U.S. citizens. Filing it starts a process that includes a background check, a biometrics appointment, an interview with English and civics tests, and an oath ceremony. The form itself asks for your residential and employment history, travel outside the United States, marital history, criminal record, and your willingness to take the Oath of Allegiance.

Who Can File

You must be at least 18 years old when you submit the form.¹ The standard path requires five years of continuous residence as a lawful permanent resident. If you are married to and living with a U.S. citizen who has held citizenship for at least three years, the requirement drops to three.²

You do not have to wait until the exact anniversary. USCIS lets you file up to 90 days before you would first meet the continuous residence requirement, though you will not be naturalized until you actually reach it.³

Continuous Residence and Physical Presence

Continuous residence means your home has stayed in the United States throughout the statutory period. An absence of more than six months but less than a year raises a presumption that continuous residence was broken; you can rebut it by showing ties like a job, lease, or family in the U.S.⁴ Absences of a year or more are much harder to explain and can reset the residency clock entirely.

Physical presence is a separate count: at least 30 months in the United States during the five-year period, or 18 months during the three-year spousal period.⁵ You also need to have lived in the state or USCIS district where you file for at least three months before submitting the application.⁶

Military Applicants

Active-duty service members who have served honorably for at least one year can apply while still serving or within six months of discharge, and the standard residency and physical presence requirements are waived entirely.⁷ Filing fees are waived as well. Those who left the military more than six months ago can still apply, but their service time counts toward the standard residency and physical presence calculations rather than exempting them.

Good Moral Character

USCIS requires good moral character throughout the statutory period. This is where naturalization cases most often break down, and it covers more ground than applicants expect.

Two categories of criminal history are permanent bars regardless of when they occurred: a murder conviction, and an aggravated felony conviction on or after November 29, 1990.⁸ If either applies, naturalization is not available.

Within the statutory period, other conduct will also bar a finding of good moral character:

Convictions for crimes involving moral turpitude, such as fraud, theft, or assault
Any controlled substance conviction other than simple possession of 30 grams or less of marijuana
Two or more convictions with an aggregate sentence of five years or more
Confinement in jail or prison for 180 days or more during the statutory period
False testimony under oath given to obtain any immigration benefit, even if the false information was not material
Two or more gambling convictions, or income earned principally from illegal gambling

Because these bars are tied to the statutory period, some applicants choose to wait until disqualifying conduct falls outside the window before filing.

Taxes and Selective Service

USCIS expects you to have filed required federal, state, and local tax returns for every year you have been a permanent resident. Spousal applicants need IRS-certified returns or transcripts for the past three years; standard applicants should have five years.⁹ Owing back taxes is not an automatic bar, but bring any IRS correspondence and repayment agreements to your interview. Ignoring tax obligations can sink the good moral character finding.

Male applicants who lived in the United States between ages 18 and 26 must have registered with the Selective Service System. Failure to register can block naturalization for men under 31 at the time of filing. Men between 26 and 31 who did not register may still naturalize if they can show the failure was not knowing or willful. Applicants over 31 are generally unaffected because the failure falls outside the statutory period.¹⁰

What the Form Asks For

The N-400 is an exercise in record-keeping. It asks for every residential address and employer covering the past five years with no gaps, every trip outside the United States during that period with exact departure and return dates, and information on current and previous spouses.

Supporting documents back up what you write. At a minimum, gather:

A photocopy of both sides of your Permanent Resident Card
Your current marriage certificate if applying based on marriage, plus proof that all prior marriages ended
IRS-certified tax returns or transcripts covering the statutory period
Certified court records for any arrest, charge, or conviction, even if the case was dismissed
Passport pages showing entry and exit stamps if you have traveled extensively

The form is available on the USCIS website for online filing or as a downloadable PDF.¹¹ Enter your name exactly as it appears on your green card, and follow the instructions for sections that do not apply to you.

Filing Fees and Waivers

The standard filing fee is $710 online or $760 by paper.¹² There is no separate biometrics fee. Military applicants pay nothing.

Households earning between 150 percent and 400 percent of the Federal Poverty Guidelines qualify for a reduced fee of $380. To claim it, you must file on paper and complete Part 10 of the form; no separate waiver form is needed. The 400 percent threshold for a single-person household is $63,840 in 2026, and $132,000 for a family of four.¹³

If your household income is below 150 percent of the guidelines, or you currently receive a means-tested benefit like Medicaid or SNAP, you can request a full waiver using Form I-912 and include proof of the benefit.¹⁴

After You File

You can file online through a USCIS account or mail a paper application to a designated USCIS Lockbox. Online filing gives you real-time tips as you complete the form, case tracking, and notifications through your account.¹⁵

USCIS sends a Form I-797C, Notice of Action, confirming receipt, with a receipt number you can use to check status online.¹⁶ You may then be scheduled for a biometrics appointment at a local Application Support Center for fingerprints and photographs. In some cases USCIS reuses biometrics already on file and skips this step.

Processing times vary by field office. The national median runs about five to six months from filing to oath, though applicants in busier metropolitan offices sometimes wait eight months or longer.

The Interview and Tests

A USCIS officer places you under oath and goes through your N-400 line by line, checking that every answer is still accurate. Disclose anything that has changed since you filed, whether it is a new job, a move, a marriage, or contact with law enforcement. Failing to mention a material change can be treated as misrepresentation and lead to denial.

English

The English test covers reading, writing, and speaking. Speaking is assessed naturally through the interview itself. For reading, you read one sentence aloud correctly in up to three attempts. For writing, the officer dictates a sentence and you write it, again with up to three tries.¹⁷ You are not penalized for an accent, and minor spelling or punctuation errors do not fail you as long as meaning is clear.

Civics

Applicants who file on or after October 20, 2025, take the 2025 civics test. The officer asks up to 20 questions drawn from a list of 128, and you must answer at least 12 correctly.¹⁸ The previous version, which asked 10 questions and required 6 correct answers, applies only to applicants who filed before that date.¹⁹ Study materials and practice tests are on the USCIS website.

If You Fail a Test

Failing English or civics does not end your case. USCIS must give you a second opportunity within 60 to 90 days, and you retake only the portion you failed.²⁰ Skipping the appointment without asking to reschedule leads to denial for failing the educational requirements.

Test Exemptions and Disability Accommodations

Not everyone takes the same tests. USCIS provides exemptions based on age and time as a permanent resident:

Age 50 or older with 20 years as a permanent resident: exempt from English, and the civics test can be taken in your preferred language through an interpreter
Age 55 or older with 15 years as a permanent resident: the same English exemption and interpreter option
Age 65 or older with 20 years as a permanent resident: given a shorter civics test drawn from a designated list of 20 questions

These are commonly called the 50/20, 55/15, and 65/20 rules.²¹

If a physical, developmental, or mental impairment prevents you from learning English or civics, you may qualify for a medical disability exception. A licensed medical professional completes Form N-648, certifying that the condition has lasted or is expected to last at least 12 months and explaining specifically how it prevents you from meeting the testing requirements. The form must be signed no more than 180 days before you file the N-400.²² USCIS scrutinizes these forms closely; a vague diagnosis without a clear connection to the testing inability will not be enough.

If You’re Denied

A denial is not the final word. You can request a hearing before a different immigration officer by filing Form N-336 within 30 calendar days of receiving the denial, or 33 days if the decision was mailed to you.²³ USCIS generally rejects late filings. The N-336 fee is $780 online or $830 on paper, with no fee if the original N-400 was filed based on military service.²⁴ You may bring an attorney or accredited representative to the hearing and present additional evidence.

The Oath of Allegiance

Once the officer approves your application and you pass the tests, the final step is the Oath of Allegiance. Some applicants take the oath the same day as their interview if a ceremony is available at that office; otherwise USCIS mails a Form N-445 with the date, time, and location.²⁵

At the ceremony you surrender your Permanent Resident Card and receive a Certificate of Naturalization, your official proof of U.S. citizenship.²⁶ With that certificate you can apply for a U.S. passport and register to vote in federal elections immediately. Keep it in a safe place. Replacing it requires a separate application and fee.

1
U.S. Citizenship and Immigration Services. I Am a Lawful Permanent Resident of 5 Years
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U.S. Citizenship and Immigration Services. Chapter 3 – Spouses of U.S. Citizens Residing in the United States
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U.S. Citizenship and Immigration Services. Chapter 6 – Jurisdiction, Place of Residence, and Early Filing
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U.S. Citizenship and Immigration Services. Continuous Residence and Physical Presence Requirements for Naturalization
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eCFR. 8 CFR Part 316 – General Requirements for Naturalization
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U.S. Citizenship and Immigration Services. Chapter 3 – Continuous Residence
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Office of the Law Revision Counsel. 8 USC 1439 – Naturalization Through Service in the Armed Forces
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eCFR. 8 CFR 316.10 – Good Moral Character
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U.S. Citizenship and Immigration Services. Document Checklist
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Selective Service System. USCIS Naturalization and SSS Registration Policy
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U.S. Citizenship and Immigration Services. N-400, Application for Naturalization
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U.S. Citizenship and Immigration Services. Fact Sheet – Form N-400, Application for Naturalization Filing Fees
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U.S. Citizenship and Immigration Services. Poverty Guidelines
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U.S. Citizenship and Immigration Services. Request for Fee Waiver
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U.S. Citizenship and Immigration Services. File Online
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U.S. Citizenship and Immigration Services. Form I-797 – Types and Functions
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U.S. Citizenship and Immigration Services. Scoring Guidelines for the U.S. Naturalization Test
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U.S. Citizenship and Immigration Services. 2025 Civics Test
19
Federal Register. Notice of Implementation of 2025 Naturalization Civics Test
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U.S. Citizenship and Immigration Services. Chapter 4 – Results of the Naturalization Examination
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U.S. Citizenship and Immigration Services. Chapter 2 – English and Civics Testing
22
U.S. Citizenship and Immigration Services. Chapter 3 – Medical Disability Exception (Form N-648)
23
U.S. Citizenship and Immigration Services. Request for a Hearing on a Decision in Naturalization Proceedings (Under Section 336 of the INA)
24
U.S. Citizenship and Immigration Services. G-1055 Fee Schedule
25
U.S. Citizenship and Immigration Services. Naturalization Ceremonies
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USAGov. Certificate of Citizenship or Naturalization