Conscription in South Korea
By law, when a Korean man turns 18 years old, he is enlisted for "first citizen service," meaning he is liable for military duty, but is not yet required to serve. When he turns 19 years old (or, in some instances, 20 years old), he is required to undergo a physical exam to determine whether he is suitable for military service. The table below shows the physical exam's possible grades and their outcomes, according to the Military Service Act. Men must enlist by the time they turn 28 (Korean age).
The length of compulsory military service in South Korea varies based on military branch. Active duty soldiers serve 21 months in the Army or Marine Corps, 23 months in the Navy, and 24 months in the Air Force. After conscripts finish their military service, they are automatically placed on the reserve roster and are obligated to attend a few days of annual military training for 6 years.
Singapore Armed Forces
Under the Enlistment Act 1970, conscription is mandatory for all "persons subject to [the] act", defined as those who are not less than 16 years and 6 months of age and not more than 40 years of age, with some exemptions and with no specific bias to gender (not limited to males). In practice however, it is only compulsory for all fit and able-bodied Singaporean men who have reached 18 years of age, and are not deferred for certain reasons, to be conscripted in military service, or Full-time National Service (NSF).