How to Become a US Citizen Through Naturalization

Becoming a U.S. citizen through naturalization means moving from lawful permanent resident to citizen by meeting a set of statutory requirements, filing Form N-400, passing an interview and a two-part test, 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. What follows walks through each requirement and each step in the order you’ll encounter them.

Who Qualifies

You must be at least 18 when you file.¹ The standard path requires five continuous years of lawful permanent resident status before filing.² If you are married to and living with a U.S. citizen, the requirement drops to three years, but your spouse must have been a citizen for that entire period.³

You can file up to 90 days early. USCIS counts back 90 calendar days from the day before you first meet the continuous residence requirement.⁴ Filing inside that window lets processing begin sooner, but approval waits until every requirement is met.

Residence and Time Abroad

Continuous residence means you have kept your primary home in the United States for the entire statutory period. Trips are allowed, but longer absences create problems. A trip of more than six months but less than a year triggers a legal presumption that you broke continuous residence.⁵ You can rebut it with evidence, such as showing your family stayed behind, you kept your job, or you maintained a lease or mortgage. An absence of a year or more automatically breaks the clock, and it restarts from zero.²

Physical presence is counted separately. You need at least 30 months in the country if you’re on the five-year path, or 18 months if you’re on the three-year path.² Every day outside the country counts against this, including short vacations. Keep a travel log; USCIS will compare your reported trips against your passport stamps.

Good Moral Character

USCIS reviews your conduct during the statutory period. A murder conviction at any time permanently bars you, and an aggravated felony conviction on or after November 29, 1990 does the same.⁶ A conviction for a crime involving moral turpitude during the statutory period also blocks a finding of good moral character.

Taxes matter. USCIS considers whether you have filed returns and paid what you owe.⁷ Unfiled returns or unpaid balances don’t automatically disqualify you, but they will draw scrutiny. Resolve tax issues before filing.

Male applicants who lived in the United States between ages 18 and 26 were required to register with the Selective Service. Knowingly failing to register, if that failure falls within the statutory period, will result in denial.⁸ Applicants between 26 and 31 must show the failure wasn’t knowing or willful. After 31, the failure falls outside the statutory period and generally won’t prevent approval. If you’re under 26 and haven’t registered, do so before filing.

The English and Civics Test

Federal law requires you to show basic English literacy and knowledge of U.S. history and government.⁹ The English portion covers reading, writing, and speaking: you’ll read one sentence aloud and write one sentence during the interview, both using everyday vocabulary. The civics portion is oral. The officer asks up to 10 questions from a list of 100, and you need at least 6 correct.¹⁰

If you fail either portion, USCIS reschedules you between 60 and 90 days later. The re-test covers only what you failed, on different forms. Failing a second time results in denial.¹¹

Age and Disability Exceptions

The English requirement is waived if you meet one of two combinations of age and residency at the time you file:⁹

At least 50 years old with at least 20 years as a permanent resident (the “50/20” rule).
At least 55 years old with at least 15 years as a permanent resident (the “55/15” rule).

Both groups still take the civics test, but they can take it in their native language through an interpreter. Applicants who are at least 65 with 20 or more years of permanent residence take a simplified civics test drawn from a shorter list of questions.

If a physical, developmental, or mental impairment prevents you from learning either subject, you can request an exception to both requirements. A licensed doctor, osteopath, or clinical psychologist must certify the condition on Form N-648, showing it is medically determinable, has lasted or will last at least 12 months, and directly prevents you from meeting the testing requirement.¹² The certification must be completed no more than 180 days before you file. Advanced age or illiteracy alone do not qualify.

Filing Form N-400

The Application for Naturalization, Form N-400, is available online or on paper through the USCIS website.¹³ The form asks for a detailed picture of your statutory period: every address, every employer with dates, and every trip outside the country since you became a permanent resident. Those trip dates feed the physical presence calculation, so accuracy pays off.

All applicants send a copy of both sides of their Permanent Resident Card. Applicants filing on the marriage basis add the marriage certificate and proof of the spouse’s citizenship. Any earlier marriages that ended in divorce or death need documentation showing they were legally ended before the current one. IRS tax transcripts help on two fronts, showing filing compliance and confirming U.S. residence. Make sure the addresses on your N-400 match what the IRS has, because inconsistencies commonly trigger requests for more evidence.

Filing on paper costs $760. Filing online costs $710. Both include the biometrics fee, which is no longer charged separately.¹⁴ Active-duty service members pay nothing. If you can’t afford the fee, file Form I-912 with your application to request a full waiver. Household income at or below 150 percent of the federal poverty guidelines is the primary basis for approval.¹⁵ Receipt of a means-tested benefit or documented financial hardship also supports a waiver.

What Happens After You File

Biometrics

Once USCIS accepts your application, you’ll get a notice for a biometrics appointment at a local Application Support Center, where officials collect your fingerprints, photograph, and digital signature. These feed an FBI fingerprint check and a search of the FBI’s National Name Check Program, along with additional inter-agency security checks.¹⁶ Your case doesn’t move forward until these clear.

The Interview

Every applicant appears in person before a USCIS officer for an examination that covers every eligibility factor.¹⁷ Under oath, the officer walks through your N-400 answers, asks about anything that needs clarification, and administers the English and civics tests in the same session. You can bring an attorney or accredited representative. Bring your green card, valid passport, and originals of any documents you filed as copies.

The Oath

Passing the interview leaves one step: a public ceremony where you take the Oath of Allegiance. The oath renounces allegiance to any foreign state, pledges support and defense of the Constitution, and includes a promise to bear arms or perform civilian service if required by law.¹⁸ Some offices hold same-day ceremonies right after a successful interview; others schedule the ceremony days or weeks later.¹⁹ The moment you take the oath, you are a citizen, and you receive your Certificate of Naturalization at the ceremony.

If Your Application Is Denied

You have 30 calendar days after receiving a denial (33 days if it was mailed) to file Form N-336, which requests a hearing before a different officer.²⁰ Missing that deadline generally means USCIS will reject the request without refunding the fee. If the hearing also results in denial, you can seek judicial review in federal district court.

Common reasons for denial include criminal history that undermines good moral character, trips abroad that broke continuous residence, and unresolved tax issues. Many of these are fixable with time. Once you resolve the underlying problem and enough time has passed for it to fall outside the statutory period, you can file a new N-400.

The Military Path

Service members have their own routes. Under the peacetime provision, a permanent resident who has served honorably for at least one year total can naturalize without meeting the five-year continuous residence or physical presence requirements, provided the application is filed while still in service or within six months of an honorable discharge.²¹

During a designated period of hostility, anyone who has served honorably on active duty or in the Selected Reserve of the Ready Reserve for any length of time can apply, regardless of age or whether they are a permanent resident, as long as they were in the United States at enlistment or later lawfully admitted.²² The United States has been in a designated period of hostility since September 11, 2001, and that designation stays until terminated by executive order. No filing fee applies in either military pathway.

After You Take the Oath

Register to vote. Federal, state, and local elections are now open to you.²³ Many ceremonies hand out registration materials; vote.gov and your state election office work too.

Update your citizenship status with the Social Security Administration by applying for a replacement Social Security card. Schedule an appointment and bring proof of your identity and your new citizenship status. The updated card arrives by mail within 5 to 10 business days.²⁴ Some employers and government systems verify citizenship through SSA records, so this step matters.

You’re also eligible to apply for a U.S. passport, which you can do immediately using your Certificate of Naturalization as proof of citizenship. Citizenship provides permanent protection against deportation and opens federal jobs that require U.S. citizenship.

1
Office of the Law Revision Counsel. 8 USC 1445 – 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 – Jurisdiction, Place of Residence, and Early Filing
5
U.S. Citizenship and Immigration Services. USCIS Policy Manual – Continuous Residence
6
eCFR. 8 CFR 316.10 – Good Moral Character
7
U.S. Citizenship and Immigration Services. USCIS Policy Manual – Adjudicative Factors
8
U.S. Citizenship and Immigration Services. USCIS Policy Manual – Attachment to the Constitution
9
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
10
U.S. Citizenship and Immigration Services. The Naturalization Interview and Test
11
U.S. Citizenship and Immigration Services. USCIS Policy Manual – English and Civics Testing
12
U.S. Citizenship and Immigration Services. USCIS Policy Manual – Medical Certification for Disability Exceptions
13
U.S. Citizenship and Immigration Services. N-400, Application for Naturalization
14
U.S. Citizenship and Immigration Services. Fact Sheet – Form N-400 Application for Naturalization Filing Fees
15
U.S. Citizenship and Immigration Services. Poverty Guidelines
16
U.S. Citizenship and Immigration Services. USCIS Policy Manual – Background and Security Checks
17
eCFR. 8 CFR 335.2 – Examination of Applicant
18
eCFR. 8 CFR 337.1 – Oath of Allegiance
19
U.S. Citizenship and Immigration Services. USCIS Policy Manual – General Considerations for All Oath Ceremonies
20
U.S. Citizenship and Immigration Services. N-336, Request for a Hearing on a Decision in Naturalization Proceedings
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
Vote.gov. Voting as a New U.S. Citizen
24
Social Security Administration. Update Citizenship or Immigration Status