Abstract: INTRODUCTION: Discrimination, bullying, and hazing are often not reported through existing, formal military channels. Self-reported assessments may better capture occurrences and aid in developing military policies, trainings, and interventions responsive to these adverse behaviors. METHODS: Using 2019-2021 Millennium Cohort Study survey data, self-reported experiences of discrimination, bullying, and hazing, overall and within a military context, were examined by sociodemographic and military characteristics. Adjusted modified Poisson regression models with robust error variance examined the association between military characteristics and experiences of military-specific discrimination, bullying, and hazing. RESULTS: Among 73,293 participants, 22,818 (31 %) reported discrimination, 14,844 (20 %) bullying, and 9535 (13 %) hazing. Most personnel (74-80 %) reported that one or more of these experiences occurred in a military context. Personnel who were active-duty, in the Navy or Army, and lower ranked were more likely to report military-specific discrimination, bullying, and hazing experiences. DISCUSSION: Over 40 % of all service members in the current study reported experiences of discrimination, bullying, and/or hazing, with most reporting at least one of these experiences within a military context. Findings further highlight that these adverse experiences continue to persist within certain components, pay grades, and branches of the US military. More actions, such as targeted interventions, are needed to ensure unit cohesion within military settings and to promote well-being and readiness for all personnel.