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Guides / How to Fill Out Form N-400, Part by Part

How to Fill Out Form N-400, Part by Part

Updated: October 30, 2026

Form N-400, the Application for Naturalization, has 16 parts. You fill in Parts 1 through 14 before filing. Parts 15 and 16 are signed later, at your interview and at the oath. The keys to a smooth application are a complete travel history, an honest and complete answer to every "Have you ever" question, and a correct eligibility box in Part 1. This guide follows the current edition (dated 01/20/25 as of 2026). Check uscis.gov/n-400 for the edition in use before you start.

Before you start: gather this information

Filling in the form takes much less time if you have these ready:

Part 1: Information about your eligibility

Select exactly one box. The common choices are the general provision (5 years as a green card holder), spouse of a U.S. citizen (3 years), VAWA, spouse of a citizen in qualifying employment abroad, and the military categories. Selecting more than one box, or none, can delay or reject your application.

Part 2: Information about you

This part covers your current legal name, other names you have used (maiden names, nicknames and earlier spellings), your date of birth, the date you became a permanent resident, and your country of birth and citizenship.

Three items deserve care:

Enter your A-Number as 9 digits. If it has fewer, add leading zeros, so A12345678 becomes A012345678.

Part 3: Biographic information

This part asks for ethnicity, race, height, weight, eye color and hair color. It's quick, but make sure it matches your ID documents.

Part 4: Information about your residence

List every address where you lived during the last 5 years (or 3), starting with the current one. Leave no gaps in the dates. A gap prompts questions about where you were.

Part 5: Marital history

Enter your current marital status, the number of times you have been married, and details about your current spouse. Spouse applicants also enter the date the spouse became a citizen. If you or your spouse were married before, list how each earlier marriage ended. Under the spouse rule you will later need proof that all earlier marriages were legally ended.

Part 6: Information about your children

List all your sons and daughters, of any age, living or deceased, born in or outside marriage, including stepchildren and adopted children. Leaving out a child is a common error and can cause problems if the child later applies for immigration benefits.

Part 7: Employment and schools

List your jobs and schools during the statutory period, most recent first. Periods of unemployment, self-employment and retirement count as entries too. Write "unemployed" with the dates rather than leaving a gap.

Part 8: Time outside the United States

List every trip outside the country during the last 5 years (3 under the spouse rule). That includes short drives into Canada or Mexico. For each trip, enter the dates you left and returned and the countries you visited. Officers compare this list with government entry and exit records.

Add up your days abroad before you file. You need at least 913 days of physical presence under the 5-year rule, or 548 under the 3-year rule. Any trip longer than 6 months needs supporting evidence. Read continuous residence and physical presence.

Part 9: Additional information about you

This is the longest and most important section. It contains a series of yes/no questions about:

If you answer "Yes" to any question, explain it in Part 14 and bring documents. Lying or leaving something out is often worse than the underlying issue, because false testimony can itself show a lack of good moral character.

Part 10: Request for a fee reduction

Fill this in only if you are asking for the $380 reduced fee. That requires household income at or below 400% of the Federal Poverty Guidelines and proof such as tax returns. Reduced-fee requests must be filed on paper. See the N-400 filing fee guide.

Parts 11 to 14: Contact, signatures and extra space

Parts 15 and 16: Leave blank

Part 15 is signed at your interview. Part 16, the Oath of Allegiance, is signed at the ceremony.

Common mistakes to avoid

Once the form is done, choose how to submit it: see filing online or by mail.

Frequently asked questions

How long does it take to fill out Form N-400?

With your documents ready, most people need a few hours. Collecting the travel history and addresses for the last 5 years often takes longer than the form itself.

What if I made a mistake after filing?

Bring the correction to your interview. The officer reviews the form with you under oath and can note changes. For major errors, ask an attorney whether it's better to send updated information earlier.

Do I need to send passport photos?

Most applicants living in the United States don't send photos with the N-400, because photos are taken at biometrics. Certain applicants living abroad, such as some military applicants and spouses, must send two passport-style photos. USCIS may also ask for photos later.

Should I disclose an arrest that was expunged?

Yes. The N-400 asks about arrests and charges even if records were sealed or expunged. Disclose them and bring certified court records to the interview.

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Informational article, not legal advice. Civio is not affiliated with USCIS or any government agency; always check current requirements at uscis.gov.

Keep reading: How to Pass the Civics Test: A Practical Study Method · Military Naturalization: Becoming a Citizen Through Service · N-400 Denied - Your Options, Deadlines, and the N-336 Hearing · Example civics test questions