Screening for posttraumatic stress disorder (PTSD) is highly relevant for youth involved in the juvenile justice system, given their high rates of trauma exposure and posttraumatic stress symptoms; however, to date, no studies have investigated the implications of the recent revisions to the Diagnostic and Statistical Manual for Mental Disorders (5th ed., DSM-5; American Psychiatric Association [APA], 2013) diagnostic criteria for PTSD for screening in this population. Participants included 209 youth (60 girls) aged 13-19 (M = 15.97, SD = 1.24). Youth completed measures of lifetime trauma exposure and past-month posttraumatic stress symptoms. In the current study, just over 95 percent of youth in the sample reported exposure to at least one type of traumatic event. Approximately 19.60 percent of the sample screened positive for PTSD according to the DSM-5, compared to 17.70 percent according to the DSM-IV-TR. Girls were more likely than boys to screen positive for PTSD according to the DSM-IV-TR compared to the DSM-5. The main factors that account for the differences in screening rates across the versions of PTSD criteria involved the removal of Criterion A2 from the DSM-5, the separation of avoidance symptoms (Criterion C) into their own cluster, the addition of a cluster involving negative alterations in cognitions and mood (Criterion D), and revisions to the cluster of arousal symptoms (Criterion E). Future research should continue to investigate gender differences in PTSD symptoms in youth and consider the implications of these diagnostic changes for the accurate diagnosis and referral to treatment of adolescents who demonstrate posttraumatic stress reactions. (Publisher abstract modified)