This article examines the South Korean military's treatment of trans people in the context of all “able-bodied men” being conscripted for two years. While trans men are exempt from service because they are not considered able-bodied men, trans women pose a significant complication for the rigid military conscription system, given that most trans women in their early twenties—the time when most will be drafted into service—have yet to change their legal gender identification. As the military's definition of one's anatomical makeup is the key criterion for conscription or exemption, the transgender body is a material manifestation of the insecurities of a rigid sex/gender system perpetuated by a masculine and patriarchal military institution. Written on the bodies of trans people is the militarization of the sex/gender system. The Cold War–born Korean military—a geopolitical binary pitting the Democratic People's Republic of Korea against the Republic of Korea—is faced with bodies in transition and resorts to anatomical determinism for the sake of national defense and (re)production.