In this multisite prospective study of 1,506 young adults (aged 18–24) presenting to emergency departments, the 4-item SaFETy screening tool stratified risk for interpersonal firearm violence over 12 months, with rates increasing from 1.8% (score 0) to 25% (score ≥6). The score demonstrated moderate discrimination (AUC 0.78) and retained predictive value beyond demographic, clinical, and behavioral risk factors, improving model performance when added to routine triage variables. Findings support the SaFETy score as a brief, nonintrusive tool to identify at-risk patients in ED settings and guide targeted prevention strategies.