How to Apply for Citizenship: Form N-400

Becoming a U.S. citizen is one of the most important steps in an immigrant's journey — and it starts with one form: Form N-400, Application for Naturalization. This guide explains what the form is, who can file it, and how the process works, so you can approach it with confidence.

This is general legal information, not legal advice; eligibility depends on your specific history, and a mistake on the application can cause delays or a denial. You can download the current Form N-400 (PDF) here, and always confirm you have the latest version and current fees on the official USCIS N-400 page.

Use the current edition

USCIS periodically updates its forms and will reject an outdated edition. The current Form N-400 carries Edition 01/20/25 (OMB No. 1615-0052; expires 02/28/2027) and is 14 pages. Before you file, check the edition date in the bottom-left corner of the form against the USCIS website.

Who can apply (the eligibility categories)

Part 1 of the N-400 asks you to select the basis for your eligibility. The main categories are:

• General Provision — most lawful permanent residents (green-card holders) who have held that status for at least 5 years.
• Spouse of a U.S. citizen — generally permanent residents married to (and living with) a U.S. citizen for at least 3 years.
• VAWA — certain spouses, former spouses, or children of a U.S. citizen under the Violence Against Women Act.
• Spouse of a U.S. citizen in qualifying employment abroad — under INA § 319(b).
• Military service — those who served during a period of hostilities, or who have at least one year of honorable service.
• Other — additional bases not listed above.

Each category has its own detailed requirements (continuous residence, physical presence, good moral character, English and civics knowledge, and more). The N-400 Instructions spell these out — review them carefully or speak with an attorney before choosing your basis, because selecting the wrong one can delay or derail your case.

How the process works

While every case is different, naturalization generally follows these steps:

1. File Form N-400 — online through a USCIS account or by mail, with the required fee (or a fee-waiver request). Filing online is often the fastest way to submit and track your case.
2. Biometrics — USCIS may schedule you to provide fingerprints and a photo for background checks.
3. The interview — a USCIS officer reviews your application and tests your English (reading, writing, speaking) and civics (U.S. history and government), unless you qualify for an exception or accommodation.
4. The decision — USCIS grants, continues, or denies the application.
5. The Oath of Allegiance — if approved, you take the oath at a naturalization ceremony and receive your Certificate of Naturalization. You are now a U.S. citizen.

Tips to avoid delays

• Answer every question. USCIS warns that incomplete applications take longer to process.
• Use black ink and the current edition if filing on paper.
• Be honest and thorough — especially about travel history, taxes, and any arrests or citations; gaps and inconsistencies are a common cause of problems.
• Keep copies of everything you submit.
• Don't file N-400 if you may already be a citizen. If a parent was a U.S. citizen by birth or naturalized before you turned 18, you may already be a citizen and should look at Form N-600 instead.

How we can help

Naturalization is the finish line, but the application asks detailed questions about your entire immigration and personal history — and issues like long trips abroad, tax filings, or old criminal records can complicate "good moral character" and continuous residence. As a firm led by a former U.S. Immigration Judge, we help applicants file a clean, complete N-400 and prepare for the interview. Contact us to review your eligibility before you file.

Frequently asked questions

What is Form N-400?

Form N-400, Application for Naturalization, is the form lawful permanent residents use to apply to become U.S. citizens. The current edition is dated 01/20/25.

How long must I be a green-card holder before applying?

Generally 5 years under the general provision, or 3 years if you are a permanent resident married to and living with a U.S. citizen. Military and certain other categories have different rules.

Can I file Form N-400 online?

Yes. Most applicants can file online through a free USCIS account, which lets you submit and track your case; paper filing by mail is also available.

Is there an English and civics test?

Yes — at the interview, most applicants must demonstrate basic English (reading, writing, speaking) and pass a civics test on U.S. history and government, unless they qualify for an exemption or accommodation.

How much is the filing fee?

USCIS fees change periodically, so confirm the current amount on the official USCIS N-400 page. Fee waivers and reductions are available for those who qualify.

This article is general legal information, not legal advice, and does not create an attorney–client relationship. It does not guarantee any outcome. Forms, fees, and requirements change; confirm the current edition and fees on USCIS.gov and consult a qualified immigration attorney about your specific situation.