This chapter discusses the evidence base for long-term treatment of the most common outcomes following disaster and the gaps in that knowledge base. In the past decade or two there has been a growing body of research on psychological interventions for the treatment of posttraumatic stress disorder (PTSD) following disaster. Randomized clinical trials have established the efficacy of cognitive-behavioral therapy (CBT) for the treatment of PTSD following many types of trauma. The chapter describes the dissemination of evidence-based treatments and the training and credentialing of mental health providers. Gaps in the treatment outcome literature are compounded by problems with the dissemination and acceptance of the clinical science literature by both patients and mental health practitioners in the community. The chapter illustrates the clinical presentation of symptoms and the development of treatment plans several years after a trauma.