Given the crisis of mass incarceration in the United States and the high prevalence of trauma histories among those incarcerated, it is imperative to improve service delivery to inmates in correctional facilities and to those undergoing reentry in community-based treatment settings. This article provides trauma definitions and categories, describes the sequelae of trauma, reviews research on the high prevalence of incarceration in this Nation, and reviews research on the high prevalence of trauma among the incarcerated. This article also provides a menu of evidence-based and promising treatment approaches to address the overlap among trauma, mental illness, substance abuse, and behavioral problems. A synthesis of research via seven points is meant to guide practitioner and policy responses to the national challenge of meeting the needs of those undergoing reentry. (Published Abstract)