Fill Out USCIS Form N-400 Online

What is Form N-400 used for

Form N-400 starts the naturalization process, which is how a person born outside the United States becomes a U.S. citizen. After filing, applicants typically attend a biometrics appointment if required, then an interview where a USCIS officer reviews the application and administers the English and civics tests, and finally the oath ceremony.

Approval ends with the Oath of Allegiance, after which you receive a Certificate of Naturalization and can apply for a U.S. passport.

Who files Form N-400

Most applicants qualify under one of the general residence-based rules, though military and other special provisions also exist.

• Permanent residents for at least 5 years, who are at least 18 years old.
• Permanent residents for at least 3 years who have been married to and living with a U.S. citizen spouse during that time.
• Current and former members of the U.S. armed forces under special military naturalization provisions.
• You may file up to 90 calendar days before completing the 5-year or 3-year continuous residence requirement.

How to fill out Form N-400

Gather your green card, travel records, addresses, and employment history first; the form asks for the past five years of most of it.

Because the good moral character questions and any criminal history can affect both the application and your existing status, applicants with arrests, long trips abroad, or tax issues should consult an immigration attorney or accredited representative before filing.

• Early parts confirm your eligibility basis, identifying information, and Alien Registration Number.
• The residence and employment parts ask where you have lived and worked for the past five years, with dates.
• The travel section asks you to list trips outside the United States during the statutory period, so reconstruct your travel from passport stamps and records.
• Family sections cover your marital history and children. Have marriage certificates and any divorce decrees on hand.
• The moral character part asks dozens of yes or no questions about arrests, taxes, affiliations, and other conduct. Answer honestly and attach documentation where the instructions require it.

Filing tips

You can file Form N-400 online with a USCIS account or by mail. The current paper edition is dated 01/20/25, and applicants requesting a reduced fee or fee waiver must file on paper.

• Include a copy of both sides of your Permanent Resident Card with your application.
• Check the current filing fee with the USCIS fee calculator, and review whether you qualify for a reduced fee or waiver before choosing how to file.
• Submit certified English translations for any foreign language documents.
• If a disability prevents you from meeting the English or civics requirements, Form N-648, completed by a medical professional, requests an exception.