Book excerpt: Police, firefighters, and paramedics are highly exposed to traumatic events and experience markedly higher rates of PTSD than others in the community, also facing distinct organizational challenges that complicate their stress reactions. Often, this results in needs not addressed in manuals developed for people who have survived single traumatic events. This book provides an overview of theoretical and empirical frameworks for understanding PTSD in first responders and outlines practical, evidence-based approaches to assess and treat PTSD in these populations.