As the longest war in American history draws to a close, an unprecedented number of service members and veterans are seeking care for health challenges related to transitioning home and to civilian life. Congressionally mandated screening for mental health concerns in the Department of Defense (DoD), as well as screening efforts Veterans Affairs (VA) facilities, has been established with the goal of decreasing stigma and ensuring service members and veterans with depression and posttraumatic stress disorder (PTSD) receive needed treatment. Both the DoD and VA have also developed integrated behavioral health in primary-care based initiatives, which emphasize PTSD screening, treatment, and care coordination. This article discusses the rationale for population-level deployment-related mental health screening, recent changes to screening frequency, commonly used screening instruments such as the primary care PTSD screen (PC-PTSD), PTSD checklist (PCL), and Davidson Trauma Scale (DTS); as well as the strengths/limitations of each, and recommended cut-off scores based on expected PTSD prevalence.