US Naturalization Process: Eligibility, Form N-400, and Oath

The U.S. naturalization process is the path a lawful permanent resident takes to become a citizen: filing Form N-400 with U.S. Citizenship and Immigration Services (USCIS), passing a background check, sitting for an interview with English and civics testing, and taking the Oath of Allegiance. Most applicants qualify after five years as a green card holder. Spouses of U.S. citizens qualify after three. From filing to oath usually runs six to fourteen months, depending on how busy your local USCIS office is.

Who Qualifies

You need to be at least 18 when you file, and you already need to hold a green card.¹ The standard track calls for five years of continuous residence as a permanent resident before filing.² If you’re married to and living with a U.S. citizen, the requirement drops to three years, and your spouse must have held citizenship for that entire stretch.³

You also need to show physical presence in the country for at least half of that residency period. That’s 30 months on the five-year track⁴ and 18 months on the spousal track.³ On top of that, you need to have lived in the USCIS district where you’re filing for at least three months.²

How Trips Abroad Affect the Residency Clock

Short trips are fine. A single trip of more than six months but less than a year triggers a legal presumption that your continuous residence broke. You can rebut it by showing you kept your home, job, and family ties in the U.S. throughout.⁵ An absence of a year or longer flatly breaks continuous residence, and you generally restart the clock unless you filed Form N-470 to preserve your residence before leaving and USCIS approved it. That option is narrow, mostly reserved for people working for the U.S. government, certain research institutions, or recognized religious organizations.⁶

Good Moral Character

USCIS reviews your conduct during the three- or five-year statutory period. This isn’t a personality test. The law names specific offenses and behaviors, some that block citizenship temporarily and some that block it forever.

Permanent Bars

Some convictions disqualify you regardless of when they happened. A murder conviction at any time is a permanent bar. So is a conviction for an aggravated felony on or after November 29, 1990. The aggravated felony category in immigration law is broader than most people expect, and it includes drug trafficking, firearms trafficking, money laundering over $10,000, fraud or tax evasion involving more than $10,000, certain theft or violent crimes with a sentence of at least one year, and child exploitation offenses, among others.⁷ One detail that catches people off guard: the one-year sentence threshold counts whatever the judge ordered, even if the entire sentence was suspended.

Conditional Bars

Other offenses block you only if they occurred during the statutory period. Once the window passes without a repeat, the bar lifts. These include:

Crimes involving moral turpitude, with a narrow exception for a single petty offense
Any drug-related conviction other than simple possession of 30 grams or less of marijuana
Total incarceration of 180 days or more, across any number of sentences
False testimony under oath to obtain an immigration benefit
Willful failure to support dependents or pay court-ordered obligations
Two or more DUI convictions

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Taxes matter too. USCIS expects you to have filed every required return and either paid what you owe or set up a payment plan with the IRS. Unfiled returns or unresolved tax debt can produce a denial on moral character grounds.

Selective Service Registration

Men who lived in the U.S. between ages 18 and 26 were required to register with the Selective Service System. If you’re between 26 and 31 and didn’t register, USCIS will want a status information letter from Selective Service explaining why. If you’re over 31, the failure falls outside the statutory period and no longer blocks the application on moral character grounds, though a knowing and willful failure still calls for a convincing explanation.⁹

Filing Form N-400

Form N-400 is available online through your USCIS account or as a paper form mailed to a USCIS lockbox.¹⁰ Before you start, gather several years of records. The form asks for your addresses and employment history going back five years, every trip outside the U.S. during that period with specific departure and return dates, and information about your marital history and any children.

You’ll need supporting documents. At a minimum, that means a photocopy of both sides of your green card.¹⁰ Spousal-track applicants should bring their marriage certificate and evidence of the spouse’s citizenship. USCIS may also request divorce decrees from prior marriages and IRS tax transcripts. Sloppy or incomplete travel records are one of the most common reasons applications stall, so check your passport stamps against your list before you submit.

Fees and Fee Waivers

The filing fee is $710 online or $760 by paper.¹¹ That covers your background check. There’s no separate biometrics fee.

If the full fee is a hardship, there are two options. A reduced fee of $380 is available for paper filers whose documented household income is under 400% of the federal poverty guidelines.¹² A full fee waiver is available through Form I-912 if your household income is at or below 150% of the guidelines.¹³ For 2026, the 150% threshold is $23,940 for a single-person household and $49,500 for a family of four.¹⁴ Attorney help is optional; flat fees typically range from $800 to several thousand dollars depending on complexity and location.

The Biometrics Appointment

After USCIS receives your application, you’ll be scheduled at a local Application Support Center for fingerprints, a photo, and your signature so federal agencies can run a criminal background check.¹⁵ The N-400 still requires fresh biometrics rather than reuse from a prior filing.¹⁶ Missing this appointment without rescheduling can cause USCIS to treat your application as abandoned.

The Interview and Civics Test

Several months after biometrics, USCIS schedules an in-person interview at a local field office. An officer reviews your N-400 line by line and asks about your background and moral character. Anything that’s changed since you filed — a new address, a new job, an arrest, additional travel — must be disclosed. Bring updated documentation for anything that has shifted, because inconsistencies between what you wrote and what you say raise red flags.

English and Civics

During the same interview, the officer tests your English and your knowledge of U.S. history and government.¹⁷ Speaking is judged through the conversation itself. Reading requires you to read one sentence correctly out of three tries; writing, the same.¹⁸

The civics test version depends on when you filed. Applications filed before October 20, 2025 use the 2008 test, a pool of 100 questions from which the officer asks up to 10, and you need 6 correct. Applications filed on or after October 20, 2025 use the 2025 civics test, which draws on an expanded question set with changes to administration.¹⁹ Study materials for both versions are on the USCIS website. Confirm which version applies before you start studying.

If you fail the English or civics portion, you get one more chance. The retest is scheduled 60 to 90 days after the initial interview, and you only retake the section you failed.¹⁸

Exemptions and Accommodations

Not everyone takes every part. Federal law provides age-based exemptions from the English requirement:

50/20 rule: 50 or older with at least 20 years as a permanent resident — exempt from English
55/15 rule: 55 or older with at least 15 years as a permanent resident — exempt from English
65/20 rule: 65 or older with at least 20 years as a permanent resident — special consideration on civics, including a shorter list of study questions

²⁰

People who qualify under 50/20 or 55/15 still take civics but may do so in their native language. You bring your own interpreter fluent in both languages.²⁰

If a physical or developmental disability or mental impairment prevents you from meeting the English or civics requirements, you may qualify for a medical exception through Form N-648, completed by a licensed physician, osteopath, or clinical psychologist who has examined you in person, or via telehealth where state law permits.²¹ USCIS charges no fee for the form itself, though the medical professional may charge for the exam.

The Oath Ceremony

Once USCIS approves your application, you take the Oath of Allegiance at a naturalization ceremony. Some offices hold same-day administrative ceremonies right after the interview. Others schedule a separate judicial ceremony at a federal courthouse weeks later. You don’t choose; it depends on your local office’s arrangement with the courts.²²

When you check in, you surrender your green card. If you already reported the card lost during your interview, that step is waived.²³ After reciting the oath, you receive your Certificate of Naturalization. That certificate is your proof of citizenship for applying for a U.S. passport and registering to vote.

If Your Application Is Denied

Roughly one in eight applications ends in denial. The usual reasons are failure to establish good moral character, incomplete tax filings, failing the English or civics test after two attempts, and insufficient physical presence or continuous residence.

You have 30 calendar days from the date you receive the decision (33 if mailed) to file Form N-336, Request for a Hearing on a Decision in Naturalization Proceedings. Missing that deadline usually means the late filing gets rejected.²⁴ The hearing gives you a fresh review by a different officer, and you can submit new evidence addressing whatever caused the denial.

If USCIS still hasn’t decided your case 120 days after your examination, you can ask a federal district court to intervene. The court can decide the case itself or send it back with instructions.²⁵

The Military Pathway

Active-duty service members and certain veterans have a faster, cheaper route. During designated periods of military hostilities, which have been in effect continuously since September 11, 2001, service members who served honorably are exempt from the residency and physical presence requirements entirely. They pay no filing fee.²⁶ They can file from anywhere in the world, and USCIS conducts interviews and ceremonies at military installations when possible. This pathway is open regardless of age and to service members who are not yet permanent residents, as long as they were in the U.S. at the time of enlistment or were later lawfully admitted.

What Citizenship Adds

Naturalization opens things a green card doesn’t. Citizens vote in federal, state, and local elections. They serve on juries. Under a longstanding executive order, only citizens and nationals are eligible to compete for most competitive-service federal jobs.²⁷

The family sponsorship difference is substantial. Citizens can sponsor spouses, unmarried children under 21, and parents as immediate relatives, a category with no annual cap and therefore no yearslong backlog. Permanent residents can sponsor only spouses and unmarried children, and those petitions are capped, which often creates multi-year waits. Citizens are also the only ones who can sponsor married children and siblings.

Citizenship is also permanent. You can’t lose it by living abroad, and you can’t be placed in removal proceedings the way a green card holder can after certain criminal convictions. For many people, that security is the single biggest reason to naturalize.

1
U.S. Citizenship and Immigration Services. Instructions for Application for Naturalization
2
Office of the Law Revision Counsel. 8 USC 1427 – Requirements of Naturalization
3
Office of the Law Revision Counsel. 8 USC 1430 – Married Persons and Employees of Certain Nonprofit Organizations
4
U.S. Citizenship and Immigration Services. USCIS Policy Manual Volume 12 Part D Chapter 4 – Physical Presence
5
U.S. Citizenship and Immigration Services. USCIS Policy Manual Volume 12 Part D Chapter 3 – Continuous Residence
6
U.S. Citizenship and Immigration Services. Instructions for Form N-470, Application to Preserve Residence for Naturalization Purposes
7
U.S. Citizenship and Immigration Services. USCIS Policy Manual Volume 12 Part F Chapter 4 – Permanent Bars to Good Moral Character
8
U.S. Citizenship and Immigration Services. USCIS Policy Manual Volume 12 Part F Chapter 5 – Conditional Bars for Acts in Statutory Period
9
Selective Service System. Applicants Over 31 Years of Age – USCIS Policy
10
U.S. Citizenship and Immigration Services. N-400, Application for Naturalization
11
U.S. Citizenship and Immigration Services. Form N-400, Application for Naturalization Filing Fees
12
U.S. Citizenship and Immigration Services. Additional Information on Filing a Reduced Fee Request
13
U.S. Citizenship and Immigration Services. Poverty Guidelines
14
HHS Office of the Assistant Secretary for Planning and Evaluation. 2026 Poverty Guidelines
15
U.S. Citizenship and Immigration Services. Preparing for Your Biometric Services Appointment
16
U.S. Citizenship and Immigration Services. Photograph Reuse for Identity Documents – Policy Alert
17
Office of the Law Revision Counsel. 8 USC 1423 – Requirements as to Understanding the English Language, History, Principles and Form of Government of the United States
18
U.S. Citizenship and Immigration Services. The Naturalization Interview and Test
19
U.S. Citizenship and Immigration Services. Check for Test Updates
20
U.S. Citizenship and Immigration Services. Exceptions and Accommodations
21
U.S. Citizenship and Immigration Services. N-648, Medical Certification for Disability Exceptions
22
U.S. Citizenship and Immigration Services. USCIS Policy Manual Volume 12 Part J Chapter 6 – Judicial and Expedited Oath Ceremonies
23
U.S. Citizenship and Immigration Services. Naturalization Ceremonies
24
U.S. Citizenship and Immigration Services. N-336, Request for a Hearing on a Decision in Naturalization Proceedings (Under Section 336 of the INA)
25
Office of the Law Revision Counsel. 8 USC 1447 – Hearings on Denials of Applications for Naturalization
26
Office of the Law Revision Counsel. 8 USC 1440 – Naturalization Through Active-Duty Service in the Armed Forces During Specified Periods of Hostilities
27
USAJOBS Help Center. Employment of Non-Citizens