BACKGROUND: Posttraumatic stress disorder (PTSD) is common after traumatic injury, negatively impacting recovery. Black Americans face elevated PTSD risk following traumatic injury, yet diagnostic accuracy of assessments in trauma center settings serving this population is unknown. The Posttraumatic Stress Disorder Checklist for DSM-5 (PCL-5) exhibits strong psychometric properties but optimal cut-scores by race require examination. METHODS: Data were combined from three ongoing projects of injured Black American adults (N = 270). Participants completed the PCL-5 and Clinician-Administered PTSD Scale for DSM-5 (CAPS-5) six months post-injury. Receiver operating characteristic analysis determined the PCL-5's diagnostic utility against the CAPS-5. Sensitivity, specificity, predictive values, and diagnostic efficiency were calculated across cut scores. RESULTS: Prevalence of CAPS-5 PTSD at 6-months post-injury was 34.4 %. The PCL-5 demonstrated good accuracy in detecting PTSD (AUC=.931). A PCL-5 cut-score of >
33 maximized diagnostic efficiency (89.1 %), with sensitivity of 89.1 % and specificity of 87.6 %. CONCLUSIONS: The PCL-5 is an accurate PTSD screening tool for injured Black Americans using an appropriate threshold. Findings have implications for improving mental health care access in trauma settings serving marginalized groups.