First responders are regularly confronted with exposure to traumatic events, including potentially life-threatening situations as well as the grave injuries and deaths of colleagues and civilians. Evidence indicates that the prevalence of posttraumatic stress disorder (PTSD) is substantially higher among first responders than the general population. This article provides information about the outpatient trauma services at McLean Hospital's LEADER (Law Enforcement, Active Duty, Emergency Responder) program to assist clinicians who encounter these first responders in their practices or who are specifically interested in working with this patient population. We begin by synthesizing the literature on the prevalence of PTSD in first responders following work-related exposure to traumatic stress, and by addressing the occupation-specific risk factors and the third-variable risk factors that may contribute to potentiated risk. We then discuss assessment strategies and treatment options used in our program, which is tailored for individuals who are dealing with mental health issues stemming from occupation-specific traumatic-stress exposure. We also address the unique challenges of treating traumatized first responders with more complex issues such as traumatic stress exposure across the lifespan and safety issues, including acute suicidality. We conclude by discussing notable gaps in the literature, including the need to investigate why and how women present with different PTSD symptoms than men and how these differences need to be taken into account in determining appropriate treatment for women.