Insomnia is one of the most common reasons for referral to mental health services in active duty personnel. Chronic insomnia often persists post-deployment, contributes to poor mental and physical health outcomes, and requires targeted interventions. Effective behavioral treatments of insomnia have not been adapted and tested for the treatment of chronic insomnia comorbid to combat-related mental disorders and stress reactions. In addition, effective behavioral insomnia treatments are typically delivered over an 8-week period. This format may not be easily exportable to primary and community care settings where military returnees and veterans seek help. The goal of this R34 Exploratory Clinical Research Grant is to adapt and test the effects of a 4-week behavioral treatment that targets chronic insomnia (lasting >1 month) in service members returning from Operation Iraqi Freedom (OIF) and Operation Enduring Freedom (OEF), and who present with the typical psychiatric comorbidities associated of combat-related anxiety and mood disorders and stress reactions. We call this intervention the Brief Behavioral Treatment of Insomnia for Military Veterans (BBTI-MV). The proposed study includes two phases. Phase I aims at iteratively adapting and refining a treatment manual for insomnia in OIF/OEF military returnees. Outcomes of interest include self-report, diary, and actigraphic sleep measures, as well as measures of PTSD, anxiety, and depression, and perceived physical health.