Despite affecting nearly 3% of active-duty service members, little is known about how LGBT-related stress experiences may relate to health outcomes. Thus, the present study sought to create a Military Minority Stress Scale and assess its initial reliability and construct validity in a cross-sectional study of active-duty LGBT service members (N= 248). Associations between 47 candidate items and health outcomes of interest were analyzed to retain those with substantial betas. Item response theory analyzes, reliability testing, invariance testing, and exploratory factor analysis were performed. Construct validity of the final measure was assessed through associations between the sum score of the final measure and the health outcomes. The final 13-item measure demonstrated an excellent reliability (ω= 0.95). Bivariate linear regressions showed significant associations between the sum score of the measure and overall health (β = −0.26,p< 0.001), overall mental health (β = −0.34,p< 0.001), physical health (β = 0.45,p< 0.001), life satisfaction (β = −0.24,p< 0.001), anxiety (β = 0.34,p< 0.001), depressive symptoms (β = 0.37,p< 0.001), suicidality (β = 0.26,p< 0.001), and PTSD (β = 0.42,p< 0.001), respectively. This study provides the first evidence that minority stressors in the military setting can be operationalized and measured. They appear to have a role in the health of LGBT service members and may explain the continued health disparities experienced by this population. Little is known regarding the experiences of LGBT active-duty service members, including experiences of discrimination. Understanding these experiences and their associated health outcomes during military service may therefore help and guide further etiological studies and intervention development.