The purpose of this study is to learn ways to improve treatments for women with military sexual trauma (MST). The researchers want to learn whether combining evidence-based emotion regulation skills training with a trauma-focused therapy improves treatment outcomes. An evidence-based trauma treatment known as Prolonged Exposure will be used. Emotion regulation skills will also be included in treatment. Veterans with a positive or sub threshold diagnosis of PTSD who experienced a military sexual trauma (MST) will be included. Participants will complete up to twelve 90 minute sessions of PE with Dialectical Behavior Therapy (DBT) Emotion Regulation Skills Training followed by a post-treatment assessment. All aspects of the project including consent, baseline, treatment and follow-up will be completed either in person or via videoconferencing. Fifteen participants will be enrolled.