Abstract: Thousands of service members separate from the military each year, and research has shown that they are especially vulnerable during this transition to civilian life. A 2018 executive order directed VA and DOD to develop a joint action plan to ensure access to mental health care and suicide prevention services for separating service members. The resulting plan called for mental health screenings of all service members prior to separation, among other initiatives. The House report accompanying the National Defense Authorization Act for Fiscal Year 2024 includes a provision for GAO to review VA and DOD’s implementation of mental health exams for service members transitioning out of the military. Among other topics, this report examines the extent to which VA and DOD based the joint separation health assessment’s mental health screening questions on validated screening tools and the outcomes of VA’s mental health screening using the joint assessment. To address these objectives, GAO reviewed selected scientific studies to determine the effectiveness and reliability of the joint assessment’s specific mental health screens. GAO also reviewed validated screening tool recommendations in relevant clinical practice guidelines issued by organizations including VA and DOD. GAO interviewed VA and DOD officials, as well as mental health subject matter experts identified by professional associations such as the American Psychiatric Association.