An applicant who has served for three years in the U.S. military and who is a lawful permanent resident is excused from any specific period of required residence, period of residence in any specific place, or physical presence within the United States if an application for naturalization is filed while the applicant is still serving or within six months of an honorable discharge.

To be eligible for these exemptions, an applicant must:

• have served honorably or separated under honorable conditions;
  
• have completed three years or more of military service;
  
• be a legal permanent resident at the time of his or her examination on the application; or
  
• establish good moral character if service was discontinuous or not honorable.

Naturalization Applicants Who Have Served Honorably in Any Specified Period of Armed Conflict with Hostile Foreign Forces 

This is the only section of the Immigration and Naturalization Act that allows persons who have not been lawfully admitted for permanent residence to file their own application for naturalization. Any person who has served honorably during a qualifying time may file an application at any time in his or her life if, at the time of enlistment, reenlistment, extension of enlistment or induction, such person shall have been in the United States, the Canal Zone, American Samoa, or Swains Island, or on board a public vessel owned or operated by the United States for noncommercial service, whether or not he has been lawfully admitted to the United States for permanent residence.

An applicant who has served honorably during any of the following periods of conflict is entitled to certain considerations:

• World War I - 4/16/17 to 11/11/18;
  
• World War II - 9/1/39 to 12/31/46;
  
• Korean Conflict - 6/25/50 to 7/1/55;
  
• Vietnam Conflict - 2/28/61 to 10/15/78;
  
• Operation Desert Shield/ Desert Storm - 8/29/90 to 4/11/91
  
• Operation Enduring Freedom - 9/11/01 to (open); or
  
• any other period which the President, by Executive Order, has designated as a period in which the Armed Forces of the United States are or were engaged in military operations involving armed conflict with hostile foreign forces.

Applicants who have served honorably during any of the aforementioned conflicts may apply for naturalization based on military service and no period of residence or specified period of physical presence within the United States or any State shall be required.