Naturalization is the process for legal permanent residents of the United States to become U.S. citizens. An applicant for naturalization is eligible if he or she fulfils the following criteria:

• Over 18 years old.
  
• Has been a legal permanent resident of the U.S. for the past five years (or three years if married to a U.S. citizen).
  
• Has resided in the state where he or she is filing a naturalization petition for three months prior to the application.
  
• Does not advocate or support the overthrow of the U.S. government.
  
• Can speak, read and write English.
  
• Is of good moral character.

Derivative citizenship can be obtained when a petition is filed on behalf of a child under 18 years of age whose parent is a U.S. citizen. Expedited procedures are available to naturalizing Philippine nationals who served with the U.S. armed forces during World War II, and for spouses of U.S. citizens stationed overseas.

The basic procedure for naturalization requires an applicant to do the following:

• File form N-400 and supporting documents.
  
• File fingerprint chart.
  
• Provide two photos.
  
• Pay a $225.00 fee with the INS office that has jurisdiction over the applicant's residence.
  
• Attend a formal examination at INS with or without an attorney where the alien will be interviewed, under oath, regarding information conveyed on the N-400, and examined on English literacy and American history.
  
• Attend a court or INS ceremony (if INS approves petition) for the official swearing-in and issuance of a certificate of naturalization.

Detailed requirements and exceptions

English language and American history requirement

An applicant must demonstrate literacy in English. The INS takes into consideration the applicant's education and background. An applicant over 50 years of age who was a legal permanent resident in the U.S. for 20 years ("50/20 rule"), as well as those applicants who are 55 years old and who have been legal permanent residents for at least 15 years ("55/15 rule") are not subject to the literacy requirement. They are still required to pass the U.S. government and history examination (they may be questioned through an interpreter, however).