Form N-400: How To Apply For US Citizenship

Becoming a U.S. citizen opens new doors, including the right to vote, apply for federal jobs, and sponsor family members for Green Cards.

If you are thinking of taking this important step, this article is for you.

We will walk you through the eligibility criteria, process and cost of Form N-400, breaking down complex terms into easy-to-understand information.

Bradford H. Bernstein

This article was written and reviewed by Bradford H. Bernstein, a second-generation leader at Law Offices of Spar & Bernstein, P.C., who has helped over 100,000 clients with immigration and personal injury issues. Brad joined the firm in 1993, became a partner in 1997, and assumed leadership in 2000 after Harry Spar retired.

View Brad's Bio

Bradford H. Bernstein

What Is Form N-400?

Form N-400, Application for Naturalization, is an immigration document used by Green Card holders who wish to become U.S. citizens through naturalization.

Form N-400 is filed with the U.S. Citizenship and Immigration Services (USCIS).

Form N-400 is different from Form N-600, which is used to obtain a Certificate of Citizenship if you automatically acquired U.S. citizenship through a parent.

Who Can File N-400?

Form N-400 can be filed by individuals who:

• Are at least 18 years old
• Have been lawful permanent residents for at least five years, or for three years if they married a U.S. citizen
• Have five years of continuous residence in the United States, or three years if married to a U.S. citizen
• Have been physically present in the U.S.  for at least 30 months out of the five years (or 18 months out of the three years for spouses of U.S. citizens)
• Have good moral character, meaning they have followed U.S. laws and have not been involved in serious criminal activities
• Can read, write, and speak basic English
• Know U.S. history and government (civics)

Not sure you meet all the criteria? Use USCIS’ naturalization eligibility tool to verify you have the right to file Form N-400.

Form N-400: The Process

Ready to take the first step toward becoming a U.S. citizen? Here is what you need to do.

1. Locate The Form

Download Form N-400 from the official USCIS website. Make sure you use the latest version by verifying the expiration date in the top-right corner.

2. Read The Instructions

Review Form N-400 instructions — this will help you understand the eligibility requirements, gather the necessary documents, and avoid common mistakes when completing your application.

3. Gather Required Documents

Collect necessary supporting documents such as:

• A copy of your Form I-551 (Green Card)
• A copy of the Form I-90 receipt, if you have applied to replace a lost or stolen Green Card
• Birth certificate
• Marriage certificates, if your application is based on marriage to a U.S. citizen
• Proof of name changes, if applicable
• Divorce decree, if applicable
• Any relevant documents related to legal history
• Travel history for previous 5 years (3 years if applying based on marriage to U.S. citizen)

Each case is unique and may require additional supporting documents — consult our experienced lawyers at Spar & Bernstein to ensure your application package is complete.

4. Complete Form N-400

Fill out the form, ensuring all information is accurate and matches your supporting documents. Double-check personal details and immigration history.

5. Pay The Filing Fee

Check the applicable fee based on whether you are filing Form N-400 on paper or online. Payment can be made online, by check, money order, or credit card, depending on your submission method.

6. Submit Form N-400

Choose how to file your application.

To submit electronically, create a USCIS online account.

To submit by mail, send the completed paper form and supporting documents to the correct USCIS address.

• If you live in Connecticut, Delaware, District of Columbia, Florida, Georgia, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, North Carolina, Pennsylvania, Rhode Island, South Carolina, Vermont, Virginia, or West Virginia, send your application to:

USCIS Elgin Lockbox

U.S. Postal Service (USPS):
USCIS
Attn: N-400
P.O. Box 4060
Carol Stream, IL  60197-4060

FedEx, UPS, and DHL deliveries:
USCIS
Attn: N-400 (Box 4060)
2500 Westfield Drive
Elgin, IL 60124-7836

• If you live in Alabama, Alaska, American Samoa, Arizona, Armed Forces Americas, Armed Forces Europe, Armed Forces Pacific, California, Colorado, Commonwealth of the Northern Mariana Islands, Guam, Hawaii, Idaho, Kansas, Kentucky, Marshall Islands, Micronesia, Minnesota, Mississippi, Montana, Nebraska, Nevada, New Mexico, North Dakota, Oregon, Palau, Puerto Rico, South Dakota, Tennessee, U.S. Virgin Islands, Utah, Washington, or Wyoming, mail your application to:

USCIS Phoenix Lockbox

U.S. Postal Service (USPS):
USCIS
Attn: N-400
P.O. Box 21251
Phoenix, AZ 85036-1251

FedEx, UPS, and DHL deliveries:
USCIS
Attn: N-400 (Box 21251)
2108 E. Elliot Rd.
Tempe, AZ 85284-1806

• If you live in Arkansas, Louisiana, Oklahoma, or Texas, send your N-400 to:

USCIS Dallas Lockbox

U.S. Postal Service (USPS):
USCIS
Attn: N-400
P.O. Box 660060
Dallas, TX 75266-0060

FedEx, UPS, and DHL deliveries:
USCIS
Attn: N-400 (Box 660060)
2501 S State Hwy 121 Business
Suite 400
Lewisville, TX 75067-8003

• If you live in Illinois, Indiana, Iowa, Michigan, Missouri, Ohio, or Wisconsin, mail your application to:

USCIS Chicago Lockbox

U.S. Postal Service (USPS):
USCIS
Attn: N-400
P.O. Box 4380
Chicago, IL 60680-4380

FedEx, UPS, and DHL deliveries:
USCIS
Attn: N-400 (Box 4380)
131 S. Dearborn, 3rd Floor
Chicago, IL 60603-5517

Be sure to check the correct USCIS address if you are filing N-400 as a current or former member of the military.

7. Attend Your Biometrics Appointment

If required, attend your scheduled appointment at a designated USCIS Application Support Center (ASC). During it, USCIS will take your fingerprints, photograph, and signature to conduct background checks and verify your identity.

8. Prepare For The Interview

Study for your U.S. citizenship test, which includes two parts: the English test and the civics test. Review the U.S. citizenship test questions and practice answering them.

9. Attend The Interview

Go for your naturalization interview, where you will answer questions about the information on your Form N-400, including residency, employment, personal background, and marital status.

You will also take the English test, which will assess your ability to read, write, and speak, and the civics test, which will evaluate your knowledge of U.S. history and government.

10. Wait For USCIS Decision

You will typically receive a decision on the day of the interview or within 120 days after it.

Your application can be:

• Approved: In this case, you will receive a notice for your Oath of Allegiance ceremony to officially become a U.S. citizen.
• Continued: USCIS may continue your case if they need more information or if you need to retake the English or civics test.
• Denied: USCIS will send you a letter with the reasons. You may have the right to appeal or file a new application.

Want to know about Form N-400 processing time? Read our detailed guide.

Form N-400: Cost

The cost for filing Form N-400 is as follows:

• $760 for paper filing
• $710 for online applications
• $380, if your household income is at or below 400% of the Federal Poverty Guidelines (provide proof with your application)
• There is no fee for military applicants filing under certain sections of the Immigration and Nationality Act (INA) — talk to our attorneys at Spar & Bernstein for more information.

In some situations, you may qualify for a fee waiver — check the eligibility criteria. To request a fee waiver, use Form I-912.

Need Help With Form N-400? Schedule A Consultation

If you feel overwhelmed by the amount of information around N-400 and other immigration forms, you might decide to reach out to our knowledgeable attorneys at Spar & Bernstein.

We will:

• Help you complete and file N-400
• Collect supporting documents
• Prepare you for the naturalization interview, including the English and civics tests
• Handle requests for additional information
• Appeal USCIS decision if your application is denied

Form N-400: Things To Remember

To avoid delays or denials, remember these key points when preparing and submitting your Form N-400:

• Use the latest version of Form N-565
• Ensure all details you provide are correct
• Pay the correct fee
• Mail the form to the right USCIS address
• Consider working with a lawyer

Form N-400: FAQs

Now that you know the basics of Form N-400, here are some additional frequently asked questions to help clarify the naturalization process.

Can I travel outside the U.S. while waiting for a decision on my Form N-400?

Yes, you can travel outside the U.S. after submitting Form N-400. However, you must return for your biometrics appointment, interview, and oath ceremony. Avoid trips over six months to keep your continuous residence.

What can I do if I fail the English or civics test?

If you fail your English or civics test, you will get a second chance to retake the part you failed within 60 to 90 days. If you fail again, your application will be denied.

Are there age-based exemptions for the English language test?

Yes, you are exempt from the English test if you are:

• 50 years old and have had a Green Card for 20 years
• 55 years old and have had a Green Card for 15 years

Even if you are exempt from taking the English language test, you must still take the civics test in your native language.

What is the difference between continuous residence and physical presence?

Continuous residence means living in the U.S. without taking long trips. Physical presence refers to the total number of days you were actually in the U.S.

Can I include my children on my N-400 application?

No, each applicant must file a separate N-400. Children may derive citizenship automatically if they meet certain conditions — talk to our experienced attorneys at Spar & Bernstein for more information.

What should I do if I change my address after submitting Form N-400?

If you change your address after submitting Form N-400, notify USCIS within 10 days of moving. Use Form AR-11, Alien’s Change of Address Card, or update your information online.

Will a minor traffic violation affect my N-400 application?

Minor traffic violations, like speeding tickets, typically will not affect your application. However, serious offenses or unpaid fines could impact your good moral character assessment. If you are in doubt, talk to our knowledgeable immigration lawyers at Spar & Bernstein.

Do I need an attorney to file Form N-400?

No, you don’t need an attorney to file Form N-400. However, working with an experienced attorney, like our team at Spar & Bernstein, can help if your case is complex or you have legal concerns.