How to Become a US Citizen: The Naturalization Process Stage by Stage

There are several routes to US citizenship. You can be born a citizen, acquire it from a citizen parent, or naturalize, which means you become a citizen after being born abroad as a non-citizen. This guide explains naturalization, the route used by most adults, in five stages. At the end, you will find notes on other routes, such as citizenship through a parent.

Stage 1. Before you file

Check eligibility

Naturalization has statutory requirements: age, time as a permanent resident, continuous residence, physical presence, good moral character, English and civics knowledge, and attachment to the Constitution. Read our full citizenship requirements guide and test yourself against it honestly. The USCIS naturalization eligibility tool and the Citizenshipworks screener can help.

Look for red flags and get legal screening

If you have an arrest or conviction, a long absence from the United States, unpaid taxes or child support, a past false claim to citizenship, or you think you may qualify for a test exception, speak to an immigration attorney or an accredited representative before filing. The fee is not refundable, and a denial can leave a record. Legal-aid organizations often offer free screenings.

Decide how to file

You can file Form N-400 online through a USCIS account or on paper. Online filing is cheaper (a $50 discount) and lets you upload documents. Paper filing is required if you are requesting a fee waiver or reduced fee. Read the fee guide, because DHS has proposed major fee changes.

Gather documents

Start collecting what you will need: your green card, travel history for the past five years (or three if applying through marriage), addresses and employers, marriage and divorce records, any court records, and tax records. Documents in another language need a full English translation with a translator's certification.

Stage 2. Filing

1. Complete Form N-400 using the current edition from the USCIS website. Old editions are rejected. See our N-400 guide for the sections and key terms.
2. Pay the fee exactly. A wrong amount or a declined payment gets the application returned.
3. Receive a receipt notice. USCIS sends a receipt with your case number. Use it to track your case online.
4. Keep your address current. Noncitizens must report an address change to USCIS within 10 days of moving. A change of address at the post office does not update USCIS. Missing an appointment because of a wrong address can lead to denial.

Stage 3. Waiting and background checks

• Biometrics appointment. USCIS usually schedules fingerprints and a photo at an Application Support Center. The results feed FBI and other background checks.
• Case review. An officer reviews your file. USCIS may send a Request for Evidence (RFE) asking for more documents, with a deadline. Answer fully and on time.
• Processing time. There is no fixed timeline. USCIS publishes estimated processing times for each field office on its website, and they have changed from year to year. Treat any number you read in an old blog post with caution.
• Neighborhood and character checks. Since August 2025, USCIS policy memos have told officers to evaluate good moral character on the totality of the evidence and brought back neighborhood investigations in some cases. See the requirements guide.

Stage 4. The interview and decision

You will receive a notice with the date, time and place of your naturalization interview. At the interview, an officer places you under oath, reviews your N-400 with you, tests your English, and asks civics questions. Read about each part in our interview guide and practice with the civics test explainer.

Your case then gets one of three outcomes:

Stage 5. The oath and after

You become a citizen only when you take the Oath of Allegiance, not when your application is approved. Learn what happens in our oath guide. At the ceremony you return your green card and receive a Certificate of Naturalization, your proof of citizenship.

After the ceremony:

• Check the certificate for errors before you leave.
• Apply for a US passport.
• Update your Social Security record.
• Register to vote (see the voting guide).
• If you have children under 18 who are permanent residents living with you, look into Form N-600, which documents a child's citizenship.
• Store the certificate safely. Replacing it is slow and expensive.

Other routes to citizenship

• Citizenship through a parent. A child may already be a citizen, either at birth or after a parent naturalizes, if certain conditions are met. The proof is Form N-600, not Form N-400.
• Military service. Special provisions can shorten or remove some requirements and, in some cases, waive the fee.
• Marriage to a US citizen. Spouses of citizens can apply after three years instead of five if they meet extra conditions.

Typical reasons for delay or denial

• Paying the wrong fee or using an outdated form
• Missing or untranslated documents
• Not responding to an RFE
• Not reporting an address change
• Long trips abroad that break continuous residence
• Inconsistent answers compared with previous filings or tax returns
• A criminal record or a false claim to citizenship that was not discussed with a lawyer

Sources and further reading

• USCIS, Learn About Citizenship and Form N-400
• USCIS, Check case processing times
• USCIS Policy Manual, Volume 12: Citizenship and Naturalization
• USCIS, Form N-336 and Form N-600
• Citizenshipworks
• 8 U.S.C. § 1427: requirements for naturalization

This page is general information, not legal advice. We are not affiliated with USCIS or any government agency. Last reviewed October 21, 2026.