N-400 Application For Naturalization

What is Form N-400?

The N-400, Application for Naturalization is a form used to apply for U.S. citizenship. The N400 is also known as the naturalization or citizenship application. The form is submitted to U.S. Citizenship and Immigration Services (USCIS). 

Naturalization is the process of becoming a citizen for people not born in the United States. It is for lawful permanent residents with a green card to adjust their status to a naturalized citizen.

Prepare to file Form N-400

  1. Make sure you are eligible to apply to become a U.S. citizen and that your green card is valid.
  2. Read the instructions carefully.
  3. Collect all the requested documents so you can refer to them as you complete your application.
  4. Decide if you need legal help. It is a complicated form and process. Speaking with a lawyer is recommended. There are organizations and lawyers who offer help for free, such as Citizenshipworks.  
  5. Learn the meaning of hard words and terms used in Form N400.
  6. Choose how you are going to submit Form N-400. You can file your application online or by mail.

Fill out Form N-400

If you are filling the form out online, you will need to set up an account on the USCIS website. You can work on the application at your own pace and save it as a draft online until you are ready to submit it. Find more instructions in this video:


If you are mailing in your application, you can use the PDF of Form N-400 and either:

  1. Download it and type in your answers.
  2. Print it and write in your answers. 
    If you are writing in the answer and make a mistake, start over on a new form. Do not use highlighters or white out.

Some tips to remember:

  • Use your name the way it is spelled on your green card.
  • Make sure your A-number is 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” for not applicable. If your response to a question would be zero, write “none”.
  • Answer each question truthfully. If you lie or misrepresent information, there can be severe consequences. You can be charged with a crime, lose your ability to ever become a citizen, or even be deported. Your answers will be compared to previous documentation, including overseas interviews and tax filings. If you do not know the answer to a question, explain why. 
  • Don’t forget to sign your application. USCIS will reject and return any form that is not signed.
  • Review all your answers before you submit your application.
  • Save a copy of your completed application for your reference.

Submit Form N-400

Include all the requested documents. Review the document checklist for a list of documents needed. 

  • If you are submitting online, you can upload photos of documents from your computer, phone, or tablet.
  • If you are submitting by mail, you should only submit photocopies of supporting documents, unless instructed to submit an original. If you were specifically instructed to give an original, USCIS will return it to you. 
  • All documents in another language must be translated into English by a certified translator.

Submit the correct payment. Learn more about the citizenship filing fee.

If you are submitting online, you will be directed through the process and given an opportunity to review your answers first. You will provide an electronic signature before being directed to provide payment.  

If you are submitting by mail, review USCIS filing tips and look up your USCIS lockbox address for where to send it to. Make sure to include all supporting documents, payment, and additional forms.

If you are seeking an exemption for the English or civics test, include Form N-648. If you live outside of the U.S., you must also send 2 passport-style photographs with your application.

Understanding 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?

If you filed your application online, you can log in to your USCIS account to view your receipt number and case status. If you filed by mail, 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 will also get a notice for your biometrics appointment to have your fingerprints and photograph taken. USCIS will schedule your naturalization interview after reviewing your background check results. 

If you change your address after applying, you must notify USCIS of within 10 days. You can change your address online. Changing your address with the post office will NOT change your address with USCIS. If you miss an appointment because the notice went to the wrong address, you could have your application denied or have to wait longer.

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.