The requirements for becoming a U.S. citizen largely apply to military service members and veterans as they do to civilians, but there are some useful exceptions. You might be able to complete the process sooner than ordinary applicants, even without getting a green card in some cases. A military service member or veteran is defined under federal regulations as someone who has served on active or reserve duty with the Army, the Navy, the Marines, the Air Force, the Coast Guard, or a National Guard unit that was recognized by the federal government as a reserve unit of the U.S. Armed Forces.
Honorable service in the U.S. military for at least one year, which does not need to be continuous, can make you eligible to apply for citizenship as soon as you get your green card. (This means that you have legal permanent resident status in the U.S.) This rule applies regardless of whether you actually fought in a war for the U.S. You can apply for citizenship free of charge, although you will need to meet the same eligibility requirements as civilians. Also, you must file a Request for Certification of Military or Naval Service (Form N-426) with the USCIS. An official in the military must sign this form. If you have received your discharge already, you will need to file your application within six months of the discharge to avoid returning to the rules that apply to civilians, unless you served during a war.
If you served on active duty in the military during one of the World Wars, the Korean War, the Vietnam War, the Persian Gulf War, or Operation Enduring Freedom, you may be able to apply directly for citizenship without first receiving a green card. You do not even need to have any other form of legal status. (If you do have a green card, you can apply for citizenship immediately without waiting for the five-year period.) To qualify for this exception, you will need to have served honorably and have enlisted in the military while you were on U.S. territory. This includes the 50 states as well as the Panama Canal Zone, American Samoa, Swains Island, and a non-commercial U.S. ship.
There is no minimum period of military service required. In theory, you can apply for citizenship if you served just one day on active duty during any of the wars listed above. However, you cannot realistically serve for just a day and then get your citizenship. You will need to go through basic training before the citizenship process is finalized, and you must honorably complete your term of service. If you receive your citizenship before the end of your term of service, and then you do not honorably complete your service, you will lose your citizenship. There is no fee for the N-400 application, but you will need to file Form N-426.
A spouse, parent, or child of a U.S. citizen service member who died during active duty can apply for immediate citizenship if they have a green card. If they do not have a green card, they can apply for a green card on this basis. They would need to file their Petition for Amerasian, Widow(er), or Special Immigrant (Form I-360) within two years of the service member’s death and check Box P (Other) in Part 2 (Classification Requested) of the form and write "Public Law 108-136."
Immediate family members of a foreign national service member who died during active duty in one of the wars listed above can apply for posthumous citizenship for the service member. They would need to submit Form I-644 to USCIS within two years of the death. Once the service member receives posthumous citizenship, their immediate relatives can apply for green cards through their relationship to the service member. Immediate relatives include a spouse, a parent, or an unmarried child who is under 21.
If you are a spouse of a U.S. citizen who is a military service member stationed in a foreign country, and you are a lawful permanent resident, you may be able to count your time living abroad with your spouse toward the residency requirement for becoming a citizen. You can apply for citizenship from the foreign country rather than returning to the U.S.
