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

To meet U.S. naturalization requirements, you generally need to be at least 18, hold a green card, have lived continuously in the United States for five years (or three if married to a U.S. citizen), show good moral character, and pass English and civics tests. The filing fee is $710 online or $760 by mail, and most applications move from filing to oath ceremony in about five to six months. Military service members, older long-term residents, and applicants with qualifying disabilities can qualify for significant exemptions from some of these rules.

Baseline Eligibility

Federal law sets the core qualifications. You must be at least 18, hold lawful permanent resident status, and have lived continuously in the United States for at least five years immediately before filing.¹ During those five years you must have been physically present in the country for at least 30 months total, and you need to have lived in the state or USCIS district where you file for at least three months before applying.

If you are married to a U.S. citizen, a separate provision cuts the residency requirement to three years. You must have been living in marital union with your citizen spouse for that entire period, your spouse must have been a citizen throughout, and physical presence drops to 18 months.² Spouses subjected to domestic abuse by a U.S. citizen spouse or parent may also qualify for this three-year track even if the marriage has ended.

One detail worth knowing: you can file up to 90 days before you finish the required residency period.³ If your five-year anniversary as a green card holder falls in September, the N-400 can go in as early as June.

Continuous Residence and Travel Abroad

Continuous residence does not mean you cannot leave the country, but longer trips create problems. Travel of more than six months but less than a year during the statutory period leads USCIS to presume that your continuous residence was broken.⁴ You can rebut that presumption by showing you kept your U.S. job, your immediate family stayed here, and you maintained a home in the country during the absence.

An absence of one year or more is more serious and generally breaks continuous residence entirely, resetting the clock. Some applicants who work for the U.S. government, qualifying research institutions, or certain international organizations can file Form N-470 before leaving to preserve their residence while abroad, but that form must be approved before naturalization can move forward.⁵

Good Moral Character

USCIS reviews your conduct during the statutory period (the five or three years before filing, plus the time between filing and the oath) to determine whether you meet the good moral character standard. Federal law lists specific behaviors that disqualify someone from meeting it, including being a habitual drunkard, earning income primarily from illegal gambling, giving false testimony to obtain an immigration benefit, or being confined to jail for 180 days or more based on a conviction.⁶

Permanent Bars

Two categories of offenses permanently prevent anyone from establishing good moral character, no matter how long ago they occurred. A murder conviction at any time is an absolute bar. So is a conviction for an aggravated felony on or after November 29, 1990. The immigration definition of “aggravated felony” is broader than most people expect, covering drug trafficking, firearms offenses, money laundering over $10,000, fraud over $10,000, crimes of violence with a sentence of at least one year, and many others. Participation in genocide, torture, or Nazi persecution is also a permanent bar.⁷

Conditional Bars

Conditional bars are tied to the statutory period, so you may be able to naturalize once enough time has passed. They include convictions for crimes involving moral turpitude, controlled substance violations (federal law still treats marijuana as illegal even if your state permits it), two or more DUI convictions, prostitution, smuggling someone into the country, and willful failure to support dependents.⁸ A narrow exception exists for a single offense of simple possession of 30 grams or less of marijuana.

Beyond specific listed offenses, USCIS can also deny an application based on any unlawful act reflecting poorly on character. That catch-all has been used for bank fraud, bail jumping, filing false tax returns, and making a false claim to U.S. citizenship. Consistent payment of federal, state, and local taxes and fulfillment of any court-ordered child support or alimony obligations also factor into the determination.

Selective Service Registration

Male applicants between 18 and 25 are required to register with the Selective Service System, and immigrants must do so within 30 days of their 18th birthday or 30 days of entering the United States.⁹ Failing to register can raise character questions at the interview. If you are over 31 and did not register, USCIS policy treats the failure as falling outside the statutory period, so it will not block your application on its own.¹⁰ Between ages 26 and 31, you may need to explain why you did not register and provide a status information letter from the Selective Service.

English and Civics Tests

Federal law requires naturalization applicants to demonstrate an understanding of English and a knowledge of U.S. history and government.¹¹ Each part works differently:

Speaking is evaluated during the interview itself, based on how you answer questions about your application.
Reading requires you to read aloud up to three sentences. Reading one correctly is enough to pass.¹²
Writing is dictated by the officer, up to three sentences, and again one correct sentence passes.
Civics consists of up to 10 questions drawn from a published list of 100. You need at least 6 correct.¹³

Age-Based Exemptions

Three age-and-residency combinations reduce or remove the language requirement:

Over 50 with at least 20 years as a permanent resident: exempt from the English requirement, and you may take the civics test in your preferred language.¹¹
Over 55 with at least 15 years of permanent residency: same English exemption.
Over 65 with at least 20 years of permanent residency: English exemption plus a simplified civics test drawn from a 20-question list instead of 100.¹⁴

Disability Exception

Applicants with a physical or developmental disability or mental impairment that has lasted (or is expected to last) 12 months or more can request an exception to both the English and civics requirements by filing Form N-648, certified by a licensed medical doctor, doctor of osteopathy, or clinical psychologist.¹⁵

Filing Form N-400

Form N-400 is available on the USCIS website for online filing or as a downloadable PDF to mail in.¹⁶ The form asks for a detailed personal history: every address you have lived at during the past five years, a full employment history with dates and addresses, and every trip outside the United States with exact departure and return dates. You will also provide information about your spouse and children.

Accuracy matters. USCIS cross-references your answers against your immigration file and tax returns, and inconsistencies can delay your case or raise character concerns. Along with the completed form, include a photocopy of the front and back of your green card. Applicants filing under the three-year spouse track should include a marriage certificate. Include proof of any legal name changes, and if you have any arrests or convictions, bring the court dispositions and sentencing records to your interview even if charges were dismissed.

Fees and Fee Waivers

The standard filing fee is $710 online or $760 for paper filings.¹⁶ If your household income falls at or below 150% of the federal poverty guidelines ($23,940 for a single person in 2026 in the 48 contiguous states), you can request a full fee waiver by filing Form I-912.¹⁷ If your income is above that threshold but at or below 400% of the poverty guidelines ($63,840 for a single person), you qualify for a reduced fee of $320 plus an $85 biometrics fee by filing Form I-942.¹⁸ Thresholds are higher for larger households and for applicants in Alaska and Hawaii.

Biometrics, Interview, and Oath

After USCIS receives your application, you will be scheduled for a biometrics appointment where your fingerprints, photograph, and signature are collected for a background check. An interview appointment follows, during which a USCIS officer reviews your N-400 responses, verifies your identity, and administers the English and civics tests. Bring your green card, a state-issued ID, current and expired passports, and any original documents that support your application, such as marriage certificates, divorce decrees, and court records.

If the officer approves your application, the final step is the Oath of Allegiance, taken in a public ceremony administered either by USCIS or by a federal court.¹⁹ Some USCIS offices offer same-day administrative ceremonies immediately after the interview; others schedule the ceremony later. During the oath, you renounce allegiance to foreign powers and pledge to support the U.S. Constitution. You become a U.S. citizen the moment you complete the oath, at which point you surrender your green card and receive a Certificate of Naturalization.²⁰

Naturalization Through Military Service

Active-duty service members and veterans follow a separate, more favorable track. Honorable service of at least one year during peacetime lets you file without meeting the standard five-year residency or three-month state residence requirements, as long as you apply while still serving or within six months of an honorable discharge.²¹ If more than six months have passed since separation, the standard residency rules apply, though military service counts toward both the residency and physical presence requirements.

During designated periods of military hostilities, the rules are more generous still. There is no residency or physical presence requirement, no age minimum, and no filing fee.²² Military applicants file Form N-400 with Form N-426, a certification of military service completed by the commanding officer or personnel office. Separated service members should include their DD-214 discharge papers. USCIS operates a dedicated Military Help Line at 877-247-4645 for case-specific questions.¹⁶

If Your Application Is Denied

The most common reasons for denial are failing the English or civics tests, a disqualifying criminal record, gaps in the moral character showing, or inconsistencies between the application and the applicant’s immigration file. If your application is denied after the interview, you have 30 calendar days from the date you receive the denial notice (33 days if it was mailed) to file Form N-336, a request for a hearing before a different USCIS officer.²³ Missing that deadline usually means USCIS rejects the hearing request and does not refund the fee, though a late filing may be treated as a motion to reopen or reconsider if it meets those requirements.

At the hearing you can present additional evidence, bring an attorney, and argue that the original decision was wrong. If the hearing officer also denies your case, you can seek review in federal district court. Reapplying with a fresh N-400 is another option when the basis for denial is something that can change over time, like failing the tests or resolving a tax issue.

1
Office of the Law Revision Counsel. 8 USC 1427 – Requirements of Naturalization
2
Office of the Law Revision Counsel. 8 USC 1430 – Married Persons and Employees of Certain Nonprofit Organizations
3
eCFR. 8 CFR 334.2 – Application for Naturalization
4
U.S. Citizenship and Immigration Services. Policy Manual Volume 12, Part D, Chapter 3 – Continuous Residence
5
U.S. Citizenship and Immigration Services. Policy Manual Volume 12, Part D, Chapter 5 – Modifications and Exceptions to Continuous Residence and Physical Presence
6
Office of the Law Revision Counsel. 8 USC 1101 – Definitions
7
U.S. Citizenship and Immigration Services. Policy Manual Volume 12, Part F, Chapter 4 – Permanent Bars to Good Moral Character
8
U.S. Citizenship and Immigration Services. Policy Manual Volume 12, Part F, Chapter 5 – Conditional Bars for Acts in Statutory Period
9
Selective Service System. Who Needs to Register
10
U.S. Citizenship and Immigration Services. Policy Manual Volume 12, Part D, Chapter 7 – Attachment to the Constitution
11
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
12
U.S. Citizenship and Immigration Services. Policy Manual Volume 12, Part E, Chapter 2 – English and Civics Testing
13
U.S. Citizenship and Immigration Services. Civics (History and Government) Questions for the Naturalization Test
14
U.S. Citizenship and Immigration Services. Civics Questions for the 65/20 Exemption
15
U.S. Citizenship and Immigration Services. N-648, Medical Certification for Disability Exceptions
16
U.S. Citizenship and Immigration Services. N-400, Application for Naturalization
17
U.S. Citizenship and Immigration Services. Poverty Guidelines
18
U.S. Citizenship and Immigration Services. I-942, Request for Reduced Fee
19
eCFR. 8 CFR Part 337 – Oath of Allegiance
20
U.S. Citizenship and Immigration Services. Policy Manual Volume 12, Part J, Chapter 6 – Judicial and Expedited Oath Ceremonies
21
Office of the Law Revision Counsel. 8 USC 1439 – Naturalization Through Service in the Armed Forces
22
Office of the Law Revision Counsel. 8 USC 1440 – Naturalization Through Active-Duty Service in the Armed Forces During Periods of Military Hostilities
23
U.S. Citizenship and Immigration Services. N-336, Request for a Hearing on a Decision in Naturalization Proceedings Under Section 336 of the INA