Abstract: STUDY OBJECTIVES: Nightmare Disorder (NDO) is an underdiagnosed sleep disorder causing significant impairment, particularly in active duty U.S. military personnel who experience unique stressors. Despite 59.28% of referred service members reporting nightmares and 19.76% screening positive for probable NDO, baseline diagnosis rate was only 0.60%. Our quality improvement project aimed to improve identification and diagnosis of NDO among active duty service members at our sleep disorders center by increasing the confirmed diagnosis rate from 0.60% to at least 5% within 12 months. METHODS: A quality improvement initiative utilizing tiered Plan-Do-Study-Act cycles was implemented over seven months. Interventions included standardizing documentation of Nightmare Disorder Index results on polysomnography reports, targeted provider education, and chart flagging for patients screening positive for probable NDO. Diagnostic and process data were collected at baseline and following each intervention cycle. RESULTS: The diagnosis rate of NDO increased from 0.60% at baseline to 9.12% after three Plan-Do-Study-Act cycles. The percentage of patients with probable NDO who were ultimately diagnosed (recognition rate) rose from 3.03% to 55.32%. Interventions were implemented without delaying care or increasing staff burden, surpassing the goal diagnosis rate of at least 5% within the target timeframe. CONCLUSIONS: Our interventions led to meaningful increases in NDO diagnoses that exceeded project goals. Given the significant effect of sleep disturbances and heightened mental health risks in the military, identification of this underdiagnosed disorder is clinically important and serves as the essential first step toward ensuring affected individuals receive appropriate treatment.