US Citizenship Requirements for Green Card Holders

To qualify for U.S. citizenship, a green card holder generally must be at least 18, have held lawful permanent resident status for five years (three if married to a U.S. citizen), meet physical presence and continuous residence minimums, show good moral character, and pass tests in English and civics. Those are the core U.S. citizenship requirements for green card holders, and each one has its own thresholds and exceptions worth understanding before you file Form N-400.

How Long You Must Hold Your Green Card

You must be 18 or older to file for naturalization on your own behalf.¹ There is no upper age limit. The standard track requires five years of continuous lawful permanent residence immediately before filing, with your green card valid throughout.²

The clock shortens to three years if you are married to and living with a U.S. citizen. Your spouse must have been a citizen for the full three years, and you must have been in marital union with them throughout.³ Survivors of domestic violence by a citizen spouse or parent can also use the three-year track without the marital union requirement.

You do not have to wait for the anniversary itself. USCIS accepts N-400 applications filed up to 90 calendar days before you complete the required period of continuous residence.⁴

Continuous Residence and Physical Presence

These are two separate tests. Continuous residence is about whether you kept a primary home in the United States. Physical presence is a raw day count.

Keeping Your Residence Unbroken

Your residence must remain unbroken through the full five-year or three-year period. A trip abroad of more than six months but less than one year is presumed to break continuity, and you have to rebut that presumption with evidence you did not abandon your U.S. home — a maintained residence, ongoing employment here, and U.S. tax filings during the absence, for instance.² Any absence of one year or more automatically breaks continuity, and the residency clock generally restarts when you return.

If your job will require a long stay abroad, Form N-470 can preserve your continuous residence. It is available to people working for the U.S. government, certain U.S. employers, recognized research institutions, and some religious organizations, and you must have completed at least one uninterrupted year as a permanent resident in the United States before leaving.⁵

Days You Actually Spent in the U.S.

On the five-year track, you need at least 30 months (roughly 913 days) of physical presence in the United States during those five years.⁶ On the three-year spousal track, the minimum is 18 months.⁷ Short trips are fine as long as the cumulative days on U.S. soil clear the bar.

You also need to have lived at least three months in the USCIS district or state where you file.⁷ After a move across state lines, wait out those three months before filing.

Good Moral Character

USCIS evaluates your conduct across the entire statutory period (five years or three) and through the date you take the oath. Federal law sets out both permanent and conditional bars to establishing good moral character.⁸

Permanent bars close the door for good. An aggravated felony conviction on or after November 29, 1990, permanently blocks naturalization no matter how long ago it occurred.⁹ Participation in Nazi persecution, genocide, torture, or extrajudicial killings is also a permanent bar.

Conditional bars apply only during the statutory period. They include convictions for crimes such as theft, fraud, and drug offenses (with an exception for a single possession charge involving 30 grams or less of marijuana), spending 180 or more days in jail, earning income principally from illegal gambling, and giving false testimony to obtain immigration benefits.⁸ These bars fall away once the conduct is outside the statutory period, though USCIS can still weigh older conduct as a negative factor.

The list is not the whole story. USCIS has discretion to deny for other conduct as well. Unpaid court-ordered child support, unpaid federal taxes, and unfiled tax returns during the statutory period can all sink an otherwise clean case.

Selective Service Registration for Men

This one catches applicants off guard. Nearly all men living in the United States are required to register with the Selective Service System within 30 days of turning 18, regardless of immigration status, and registration is not accepted after age 26.

If you are a man between 18 and 26, you must register before filing your N-400 or the application will be denied. Between 26 and 31, the failure to register falls inside your statutory period, and USCIS will require you to show the failure was not knowing or willful. Once you are past 31, the failure typically sits outside the five-year window and stops being a barrier.¹⁰ If you missed the deadline and are now over 26, request a Status Information Letter from the Selective Service to document why you did not register.

English and Civics Tests

At your interview, an officer tests both your English and your knowledge of U.S. government and history.

English

The English portion measures basic functional ability, not fluency. Your speaking is assessed as the officer walks you through your application. You also read one sentence aloud and write one sentence in English.

Two age-and-residence combinations exempt you from the English requirement:

50 or older at filing with at least 20 years as a permanent resident (the 50/20 rule).
55 or older at filing with at least 15 years as a permanent resident (the 55/15 rule).

If you qualify, you skip English but still take the civics test, which you may take in your native language with an interpreter you bring yourself.¹¹

Civics

The civics test is oral. The officer asks up to 20 questions from a bank of 128, and you need 12 correct to pass. The officer stops once you reach 12 correct or 9 wrong.¹² Applicants 65 or older with at least 20 years of permanent residence take a simplified version drawn from a shorter list.¹¹

Medical Waivers

If a physical or developmental disability or mental impairment prevents you from learning English or civics, Form N-648 can waive the requirement. The condition must have lasted, or be expected to last, at least 12 months, and a licensed medical doctor, osteopath, or clinical psychologist must complete the form and explain in plain language how the condition prevents you from meeting the requirement.¹³ Even with a waiver, you still need to show you understand the Oath of Allegiance.

Documents and Fees

The primary form is the N-400, available on the USCIS website, and you can file online or by mail.⁴ Before you start, pull together:

A clear photocopy of both sides of your Permanent Resident Card.
A complete travel history since you became a permanent resident, including short trips, with departure and return dates.
Every address and every employer, with dates, covering the statutory period.¹⁴
For spousal applicants: marriage certificate, proof of your spouse’s citizenship, and evidence you live together (joint bank statements, shared lease, utility bills).
Federal tax returns for the statutory period.

The filing fee is $710 online or $760 by paper.⁴ Two forms of financial help exist. Form I-912 requests a full fee waiver if you receive a means-tested benefit such as Medicaid, SNAP, or SSI, or if household income is at or below 150 percent of the Federal Poverty Guidelines.¹⁵ Form I-942 provides a reduced fee for household income above 150 percent but not more than 200 percent of the guidelines.¹⁶ The income thresholds update annually.

A Note on the Military Path

The requirements above describe the standard civilian route. If you have served honorably in the U.S. Armed Forces for at least one year total, a separate statute lets you apply without meeting the usual residence or physical presence requirements, as long as you file while still serving or within six months of an honorable discharge. Good moral character, English, and civics still apply. And citizenship acquired this way can be revoked if you are separated under other-than-honorable conditions before completing five years of total honorable service.¹⁷

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. N-400, Application for Naturalization
5
U.S. Citizenship and Immigration Services. Instructions for Application to Preserve Residence for Naturalization Purposes
6
U.S. Citizenship and Immigration Services. USCIS Policy Manual – Chapter 4 – Physical Presence
7
U.S. Citizenship and Immigration Services. Continuous Residence and Physical Presence Requirements for Naturalization
8
Office of the Law Revision Counsel. 8 USC 1101 – Definitions
9
U.S. Citizenship and Immigration Services. USCIS Policy Manual – Chapter 4 – Permanent Bars to Good Moral Character
10
U.S. Citizenship and Immigration Services. USCIS Policy Manual – Chapter 7 – Attachment to the Constitution
11
U.S. Citizenship and Immigration Services. Exceptions and Accommodations
12
U.S. Citizenship and Immigration Services. Study for the Test
13
U.S. Citizenship and Immigration Services. Medical Certification for Disability Exceptions
14
U.S. Citizenship and Immigration Services. Form N-400 – Application for Naturalization
15
U.S. Citizenship and Immigration Services. Request for Fee Waiver
16
U.S. Citizenship and Immigration Services. Instructions for Request for Reduced Fee
17
Office of the Law Revision Counsel. 8 USC 1439 – Naturalization Through Service in the Armed Forces