Describes the UCLA PTSD Reaction Index for DSM-5. The UCLA PTSD RI is a self-report questionnaire to screen for exposure to traumatic events and assess PTSD symptoms in school-age children and adolescents. The scale assesses the frequency of occurrence of PTSD symptoms during the past month (rated from 0 = none of the time to 4 = most of the time). The items map directly onto DSM-5 intrusion, avoidance, and arousal criteria, while two additional items assess associated features (fear of recurrence and trauma-related guilt). Scoring algorithms permit tabulation of UCLA PTSD-RI total score, and B, C, and D subscale scores.