Active duty
The length of compulsory military service varies based on service branches: Active duty enlisted personnel serve 18 months in the Army or Marine Corps, 20 months in the Navy, and 21 months in the Air Force (the length of military service will be reduced to 18 – 22 months by 2022.). Commissioned officers, warrant officers, and non-commissioned officers are volunteer-based, and serve longer terms than those of enlisted personnel, or as career. Non-active duty personnel such as social work personnel serve for various lengths. After conscripts finish their military service, they are automatically placed on the reserve roster.