Abstract: Reintegration stress is commonly reported by returning Veterans with post-trauma distress and associated with mental health and functioning difficulties. Interventions are needed to reduce reintegration stress and provide a pathway to improve Veterans' connections with their families, friends, and communities. The present study compared the effectiveness of Trauma Informed Guilt Reduction Therapy (TrIGR) and Supportive Care Therapy (SCT) in reducing reintegration stress, assessed by the Military to Civilian Questionnaire (M2C-Q) at post-treatment and 3- and 6-month follow-up. Data were derived from a randomized controlled trial treating U.S. military Veterans endorsing trauma-related guilt stemming from an event that occurred during deployment to the recent conflicts in Iraq and Afghanistan (N = 145). Intent to treat analyses using mixed models indicated a significant treatment * time interaction (p = .004) whereby patients randomized to TrIGR reported significantly lower reintegration stress compared to those in SCT by the 6-month follow-up. Between-condition effect sizes were d = 0.11 at post-treatment and d = 0.37 and d = 0.57 at 3- and 6-month follow-up assessments, respectively. Targeting trauma-related guilt may be an effective pathway to help facilitate the process of reintegration to civilian life for some Veterans.