| Country | Military service age and obligation |
| Kazakhstan | 18 years of age for compulsory military service; conscript service obligation - 2 years; minimum age for volunteers NA (2004) |
| Kenya | 18 years of age (est.) for voluntary service, with a 9-year obligation (2007) |
| Kiribati | void |
| Korea, North | 17 years of age (2004) |
| Korea, South | 20-30 years of age for compulsory military service, with middle school education required; conscript service obligation - 24-28 months, depending on the military branch involved (to be reduced to 18 months beginning 2016); 18-26 years of age for voluntary military service; women, in service since 1950, admitted to 7 service branches, including infantry, but excluded from artillery, armor, anti-air, and chaplaincy corps; some 4,000 women serve as commissioned and noncommissioned officers, approx. 2.3% of all officers (2008) |
| Kosovo | void |
| Kuwait |  18-30 years of age for compulsory and 18-25 years of age for voluntary military service; women age 18-30 may be subject to compulsory military service; conscription suspended in 2001 (2009) |
| Kyrgyzstan | 18 years of age for compulsory military service (2001) |
| Laos | 15 years of age for compulsory military service; minimum 18-month conscript service obligation (2006) |
| Latvia |  18 years of age for voluntary male and female military service; conscription abolished January 2007; under current law, every citizen is entitled to serve in the armed forces for life (2009) |
| Lebanon | 18-30 years of age for voluntary military service; no conscription (2007) |
| Lesotho |  18-24 years of age for voluntary military service; no conscription (2008) |
| Liberia | 16 years of age for voluntary military service; no conscription (2008) |
| Libya | 17 years of age (2004) |
| Liechtenstein | void |
| Lithuania |  19-26 years of age for compulsory military service; 18 years of age for volunteers; 12-month conscript service obligation; male registration required at age 16 (2009) |
| Luxembourg | 17-25 years of age for male and female voluntary military service; soldiers under 18 are not deployed into combat or with peacekeeping missions; no conscription; Luxembourg citizen or EU citizen with 3-year residence in Luxembourg (2008) |