N-400 Naturalization: Complete Guide to Becoming a U.S. Citizen

What Is N-400 Naturalization?

Form N-400 is the Application for Naturalization — the official USCIS form you file when you want to become a United States citizen. N-400 naturalization is the process by which a lawful permanent resident (green card holder) applies for U.S. citizenship. It's not the only path to citizenship, but it's the most common one for adults who immigrated to the U.S.

The process is more involved than filling out a form. You'll undergo a background check, attend an interview with a USCIS officer, and pass the civics and English tests. But millions of people complete naturalization successfully every year — and if you're eligible, there's no reason the process should be overwhelming if you prepare properly.

Who Is Eligible to Apply for Naturalization?

Before you file an N-400, you need to confirm you meet USCIS's eligibility requirements. The main criteria:

• Age: You must be at least 18 years old to file on your own behalf
• Lawful permanent resident (LPR): You must have a valid green card
• Continuous residence: Generally 5 years as a green card holder (3 years if married to and living with a U.S. citizen)
• Physical presence: At least 30 months physically present in the U.S. during the 5-year period (18 months for the 3-year path)
• Good moral character: No disqualifying criminal history during the statutory period (and beyond, for certain serious offenses)
• Attachment to U.S. Constitution: Willingness to support and defend the Constitution
• English language ability: Must be able to read, write, and speak basic English (some exemptions apply for age and long-term residents)
• Civics knowledge: Must pass the USCIS civics test (100 questions, 6-month study guide available)

The 3-year rule specifically requires that you've been married to and living with your U.S. citizen spouse continuously for those 3 years. It's not just about having a citizen spouse — the marriage must have been continuous and genuine.

The N-400 Application Process Step by Step

Here's what the N-400 naturalization process actually looks like from start to finish:

Step 1: Confirm Eligibility and Gather Documents

Before filing, confirm you meet all eligibility requirements. Gather your green card, tax returns, travel records (a list of all trips outside the U.S. during the past 5 years), and any relevant legal documents. If you have a criminal record — even minor arrests — gather documentation on those too.

Step 2: Complete and File Form N-400

Form N-400 is available at uscis.gov. You can file online or by paper. The form covers personal information, travel history, employment history, organizational memberships, and a series of yes/no eligibility questions. Answer every question honestly — USCIS conducts a background check, and inconsistencies between your answers and their records are a major red flag.

Step 3: Pay the Filing Fee

The current filing fee is $760 (plus a biometric services fee for some applicants). Fee waivers are available for qualifying applicants based on income. Check uscis.gov for the current fee schedule before filing, as fees can change.

Step 4: Biometrics Appointment

After USCIS receives your application, you'll receive an appointment notice for a biometrics appointment at a USCIS Application Support Center. They'll take your fingerprints and photo for the background check. Missing this appointment causes significant delays — reschedule if necessary, but don't miss it without rescheduling.

Step 5: USCIS Interview

This is the core of the N-400 process. A USCIS officer will review your application, ask questions about your background, and administer the English and civics tests during the same appointment. The interview typically lasts 20–60 minutes.

Step 6: Pass the English and Civics Tests

The English test has three components: reading (read one out of three sentences correctly), writing (write one out of three sentences correctly), and speaking (assessed throughout the interview). The civics test consists of 10 questions from the 100-question pool — you need to answer 6 correctly.

Step 7: Oath of Allegiance Ceremony

After your application is approved, you'll receive a notice for your naturalization ceremony. At the ceremony, you'll take the Oath of Allegiance to the United States, surrender your green card, and receive your Certificate of Naturalization. You're a citizen from the moment you take the oath.

The USCIS Civics Test: What You Need to Know

The civics test is the part of N-400 naturalization that most applicants spend the most time preparing for — and rightly so. The test draws from 100 official questions covering American government, history, and geography.

During your interview, the USCIS officer will ask up to 10 of these questions. You need to answer 6 correctly to pass. If you don't pass initially, you have one more opportunity to take the civics test within 60–90 days.

The questions cover:

• Principles of American democracy and the Constitution
• Structure of U.S. government (legislative, executive, judicial)
• Rights and responsibilities of U.S. citizens
• American history (colonial period through modern times)
• Geography (states, territories, borders)
• Symbols and holidays

USCIS publishes all 100 questions with their official answers at uscis.gov. There are no trick questions and no unapproved answer variations — study the official material, not third-party interpretations.

Some questions have variable answers based on current leadership (who is the current President, current Governor of your state, etc.). Learn the officials as of your interview date, not when you started studying.

English Test Exemptions

Some applicants are exempt from the English test requirement:

• 50/20 exemption: If you're at least 50 years old and have been a green card holder for 20+ years
• 55/15 exemption: If you're at least 55 and have been an LPR for 15+ years
• 65/20 exemption: If you're at least 65 and have been an LPR for 20+ years (also gets a simplified civics test)

Even if you qualify for an exemption, you still need to pass the civics test — though you may take it in your native language with an interpreter.

Good Moral Character Requirement

This is where many applicants have questions. "Good moral character" is a legal standard USCIS applies over the statutory period (5 years, or 3 years for the marriage pathway). Certain offenses permanently bar naturalization; others may be disqualifying within the statutory period but not permanently.

Permanent bars include aggravated felonies under immigration law, murder, and certain other serious crimes. Within the statutory period, arrests, convictions, failure to file taxes, and other issues can be problematic — but each situation is evaluated individually.

If you have anything in your background that concerns you, consulting an immigration attorney before filing is worth the cost. An attorney can assess your specific situation and advise whether to file, when to file, or how to document the circumstances.