This pilot trial will compare trauma-informed Cognitive Behavioral Therapy for Insomnia (CBT-I) to a psychoeducational intervention in women Veterans with comorbid insomnia and posttraumatic stress disorder (PTSD). The CBT-I intervention includes trauma-informed adaptations to an insomnia treatment and the psychoeducational intervention is modeled after usual care in a VA Women's Mental Health Clinic. The study objectives are to: 1) Iteratively refine the structure and materials of trauma-informed CBT-I in preparation for a pilot trial, 2) Pilot test the effects of trauma-informed CBT-I on PTSD treatment readiness and engagement in a sample of women Veterans, and 3) Examine potential mechanisms underlying variations in PTSD treatment readiness and engagement over time among women Veterans. Women Veterans with insomnia and comorbid PTSD who receive care at Sepulveda and West Los Angeles facilities will be recruited for the study. Those who pass an initial eligibility screen will be enrolled and written informed consent will be obtained. A baseline assessment will be completed that includes measures of PTSD treatment readiness, perceived barriers to PTSD treatment, and sleep and mental health symptoms. Then Veterans who meet all eligibility criteria will be randomly assigned to trauma-informed CBT-I (n=25) or the psychoeducational intervention (n=25). Both treatments will be provided in 5 one-on-one sessions by a trained instructor who is supervised by a behavioral sleep medicine specialist. All randomized participants (n=50) will have 2 follow-up assessments (post-treatment and 3-months). The follow-up assessments will collect information on PTSD treatment readiness, perceived barriers to PTSD treatment, and sleep and mental health symptoms. Chart reviews will be conducted 6-months post-treatment to assess number of PTSD treatment appointments attended (treatment engagement measure). Qualitative interviews will be conducted to identify mechanisms underlying PTSD treatment engagement.