Application for Naturalization/Citizenship (N-400)

Becoming a U.S. citizen is a major milestone in an immigrant’s journey. For most lawful permanent residents (green card holders), the pathway to citizenship is through the naturalization process using Form N-400. This application allows eligible individuals to apply for U.S. citizenship after meeting specific residency, physical presence, and moral character requirements.

In this guide, we’ll walk you through everything you need to know about naturalization, including eligibility, the application steps, and related citizenship options.

What Is Naturalization (Form N-400)?

Naturalization is the legal process by which a lawful permanent resident becomes a U.S. citizen. Once naturalized, you gain full citizenship rights and responsibilities — such as voting in federal elections, obtaining a U.S. passport, and sponsoring family members for immigration.

The primary way to apply is by submitting Form N-400 to U.S. Citizenship and Immigration Services (USCIS).

Eligibility Requirements for Form N-400

To apply for naturalization, you must meet specific criteria, which vary depending on your situation:

General Eligibility (5-Year Rule)

• Be at least 18 years old
• Have been a lawful permanent resident for at least 5 years
• Lived continuously in the U.S. for at least 5 years
• Physically present in the U.S. for at least 30 months within those 5 years
• Demonstrate good moral character
• Able to speak, read, and write basic English (some exceptions apply)
• Pass a U.S. civics and history test

3-Year Rule for Spouses of U.S. Citizens

• Married to a U.S. citizen
• Permanent resident for at least 3 years
• Lived with your U.S. citizen spouse for at least 3 years
• Meet the same physical presence, language, and civics requirements as above

Military Naturalization

Members and certain veterans of the U.S. Armed Forces may qualify for expedited or waived naturalization under special laws.

When to File Form N-400

USCIS allows you to file your application up to 90 days before reaching your required 3- or 5-year residency mark. This early filing helps you avoid unnecessary delays in becoming a citizen.

How to Apply for Naturalization (Form N-400)

Step 1: Prepare Your Documents

• Green card (permanent resident card)
• Marriage certificate (if applying under the 3-year rule)
• Evidence of spouse’s U.S. citizenship (if applicable)
• Tax returns or proof of continuous residence
• Travel records and addresses for the past 5 years

Step 2: Complete Form N-400

You can file online through a USCIS account or mail a paper form. Be sure to answer every question honestly and thoroughly.

Step 3: Pay the Filing Fee

The current USCIS fee is $710 for online filing and $760 for paper applications (subject to change). Some applicants may qualify for a fee waiver or reduction.

Step 4: Attend Your Biometrics Appointment

USCIS will schedule an appointment to collect your fingerprints, photo, and signature for background checks.

Step 5: Complete the Naturalization Interview

A USCIS officer will:

• Review your application
• Test your English skills (speaking, reading, writing)
• Administer the civics test (you must answer 6 out of 10 questions correctly)

Step 6: Receive a Decision

• Granted: You passed and will be scheduled for the oath ceremony
• Continued: More documents or a second interview are needed
• Denied: You will receive reasons and information on appealing or reapplying

Step 7: Take the Oath of Allegiance

Once approved, attend a formal ceremony to take the Oath of Allegiance and officially become a U.S. citizen. You will then receive your Certificate of Naturalization.

Related Citizenship Options Beyond Form N-400

There are other citizenship-related forms and processes for different situations:

• Form N-600: Certificate of Citizenship
  For individuals who acquired or derived citizenship through a parent. Not a naturalization path but proof of citizenship.
• Form N-470: Preserve Residence for Naturalization
  Allows green card holders living abroad to preserve continuous residence for future naturalization eligibility.
• Expedited Citizenship under INA §319(b)
  Enables spouses of U.S. citizens working abroad to apply for expedited naturalization without standard residence requirements.
• Form N-600K: Citizenship for Children Living Abroad
  Allows U.S. citizen parents to apply for their child’s citizenship through a temporary U.S. visit before age 18.

Each form has unique criteria and benefits. Unsure which applies to you? A legal consultation can help.

Need Help with Naturalization?

Our immigration law firm helps clients across the U.S. and abroad with naturalization and other citizenship applications. Whether you’re ready to apply or just starting to explore eligibility, we’re here to support you.

And take the next step toward U.S. citizenship with expert legal guidance.