What is Form N-400?
N-400, Application for Naturalization is a form you file to apply for U.S. citizenship. It is for people who were not born in the United States. The N400 is also known as the naturalization or citizenship application. The form is submitted to U.S. Citizenship and Immigration Services (USCIS).
Naturalization: the process by which a lawful permanent resident gains U.S. citizenship. It includes filing Form N-400, completing the naturalization interview with an English and civics test, and giving an oath of allegiance.
Naturalized citizen: someone who has obtained citizenship through the naturalization process.
Derived citizen: someone who has obtained citizenship through their US citizen parents.
Natural born citizen: someone who was born in the United States.
Prepare to file Form N-400
- Make sure you are eligible to apply to become a U.S. citizen and that your green card is valid.
USCIS offers a Naturalization Eligibility Tool to help check if you meet the requirements.
- Read the instructions for the Application for Naturalization.
- Collect all the documents asked for so you can refer to them as you complete your application.
- Decide if you need help. It is a complicated form. Professional legal help is recommended.
- Learn the meaning of hard words and terms used in Form N400.
- Choose how you are going to submit Form N-400. You can file your application online or by mail.
Fill out Form N-400
- Download and type your answers in PDF form.
- If you plan to handwrite your answers, write clearly and neatly in black ink.
If you make any mistakes, start over on a new form. Do not use highlighters or white out.
- Type or write your name the way it is spelled on your green card.
- Type or write your A-number at the top of every page.
- Answer every single question on the form.
If the question does not relate to your case, write N/A (not applicable) or none (zero).
- Answer each question truthfully.
If you do not know the answer to a question, explain why.
- Remember to sign your application. USCIS will reject and return any form that is not signed.
- Review all your answers before you submit your application.
TIP: If you do not have legal help, ask a family member or friend to review your application.
Submit Form N-400
- If you are submitting online, you must create an online account to file your Form N400.
If you are submitting by mail, review USCIS filing tips and look up your USCIS lockbox address.
- Include all the requested documents. Review the document checklist for a list of documents needed.
These should be copies of the documents unless they request the original.
- Submit the correct payment. Learn more about the citizenship filing fee.
- If you are seeking an exemption for the English and/or civics test, also include Form N-648.
- If you live outside of the US, you must also send 2 passport-style photographs with your application.
TIP: Print an extra copy of your application and supporting documents for your reference.
Find help filing Form N-400
There are free and paid services to help you fill out the form. Learn more about finding free and low-cost legal help.
Citizenshipworks offers free help with your citizenship process. They have a step-by-step guide to fill out the N400. If you need more help, they can connect you with a lawyer online.
FindHello is an app that can help you find legal support near you. Type in your city and get a list of service providers and a map with their location.
Form N-400 questions
The form is split up into 18 parts. Each section asks you questions about different things.
Part 1: eligibility
Part 2: you (name, date of birth, etc)
Part 3: disability & impairment accommodations
Part 4: contact information
Part 5: residence
Part 6: parents
Part 7: biographic information (race, ethnicity, etc)
Part 8: work & school (past 5 years)
Part 9: trips abroad (past 5 years)
Part 10: marital history
Part 11: children
Part 12: moral character (criminal history, oath, etc)
Part 13: certification & signature
Part 14-15: prepare & interpreter information
Part 16-18: completed at interview
Learn the meanings of hard words and terms
It is important to understand the words on Form N-400. It will help you fill out the form correctly. It will also help you prepare for the naturalization interview. The immigration officer will check to see if you understood each question.
What happens after I file my application?
After applying for naturalization, USCIS will mail you a receipt notice after they receive your application. You can check the status of your application online by typing in your receipt number. You can also log in to your USCIS account to view your receipt number and case status (or case history). If you mailed your application, you will get instructions on creating an online account to track your case online.
You will also get an appointment notice to get your biometrics (fingerprints and photograph) taken. The appointment will be at an Application Support Center (ASC). Learn what to expect at your biometrics appointment. USCIS will schedule your naturalization interview after reviewing your background check results.
Note: You must notify USCIS of any changes to your address within 10 days. You can change your address online.
Next: Learn what to expect at the naturalization interview and test.
The information on this page comes from trusted sources, including USA.gov and USCIS.gov. We aim to offer information in plain language that is easy to understand and updated regularly. This page is for guidance. USAHello does not give legal advice, nor are any of our materials intended to be taken as legal advice.