Posttraumatic Stress Disorder (PTSD) is a significant driver of suicide risk among Veterans, but there is a critical knowledge gap about how to treat PTSD among people at elevated risk for suicide. Although evidence-based treatments for PTSD reduce suicide risk, Veterans at high risk for suicidal behavior rarely receive these potentially life-saving treatments. Prior research suggests that a treatment that combines Dialectical Behavior Therapy (DBT) with the DBT Prolonged Exposure protocol (DBT PE) for PTSD improves both PTSD and suicide-related outcomes. This study will evaluate whether DBT + DBT PE improves these outcomes more than Prolonged Exposure plus suicide risk management, the gold standard VA care for this population. The proposed study will also examine factors that make it easier and harder to implement these treatments in VA settings. The results will help to inform treatment guidelines for this high-priority Veteran population.