After you have received your green card you can apply to become a U.S. citizen. This is called Naturalization. You are eligible to file for Naturalization ninety days prior to the fifth or third anniversary of the day you received your permanent residency depending on how you obtained your permanent residence.

Criteria for Naturalization
In order to qualify for Naturalization, an applicant must meet the following criteria:

1. The applicant must be a Lawful Permanent Resident or a Conditional Permanent Resident with the requisite residence period.

2. The applicant must be a resident of the United States for:

Five (5) years if Permanent Residence was obtained through employment or priority family sponsorship; or

Three (3) years if Permanent Residence was obtained through marriage to a United States citizen. To qualify for this shortened timing requirement, the applicant must be living in marital union with their sponsoring spouse. If the marital relationship has been terminated, the five (5) year requirement applies.

3. The applicant must be at least eighteen (18) years of age.

4. The applicant must reside in the state in which the petition will be filed for at least three (3) months prior to filing.

5. The applicant must by physically present in the United States for at least one-half of the applicable five (5) or three (3) year waiting period prior to filing.

6. The applicant must remain physically present in the United States from the time of filing until the admission of citizenship.

7. The applicant must not be absent from the United States for a continuous period of more than one (1) year during the required continuous residence period. Exceptions to this rule include:

Military service abroad

Employees working abroad who file to preserve their residency via a re-entry permit

Spouses of U.S. Citizens working abroad who are eligible for expedited citizenship

Spouse, child, or parent of a United States citizen who died in combat

Spouse of a person who was granted citizenship posthumously

7. The applicant must be a person of good moral character for the required continuous residence period. The United States Citizenship and Immigration Service reserves the right to deny applicants with any of the following:

Admissions or Convictions (eg. Nonsupport of Dependents, Homosexuality, Adultery, Failure to Register with Selective Service, Drunk Driving)

Expunged Convictions

Criminal Records

The United States Citizenship and Immigration Service also reserves the right to deny applicants who have voted unlawfully or made false claims to United States citizenship.

9. The applicant must believe in the principles of the Constitution of the United States and reveal all organizations he/she has been a member of—even if they do not seem applicable to the application.

10. The applicant must be willing to bear arms on behalf of the United States.

11. The applicant must not be barred as:

Subversive

Communist Party Member

Deserter of War

An Alien in Removal Proceedings

11. The applicant must be able to demonstrate the following:

Elementary level reading and writing abilities, as well as an understanding of the English language.

Knowledge and comprehension of the United States history and government fundamentals. The U.S. Government publishes a study guide to assist Naturalization applicants in their preparation.

If the applicant fails either of the two tests, he/she will be allowed to take a second test within ninety (90) days of the first test.