Background: Posttraumatic Stress Disorder (PTSD) affects approximately 23% of returning Veterans and produces significant psychological, physical, and economic burdens. Although most Veterans with PTSD are treated on an outpatient basis, the VA has 39 Specialized Intensive/Inpatient PTSD programs (SIPPs) designed to treat high-needs Veterans who require more intensive and closely monitored care. The treatment of patients enrolled in SIPPs is extremely costly; only 1% of VA patients with a PTSD diagnosis enroll in SIPPs but they account for 33% of VA's budget for specialized PTSD care. Furthermore, despite these costs, many patients undergoing treatment in SIPPs may experience only modest improvements in PTSD symptoms. Thus, the Institute of Medicine has recently called for strategies to improve treatment outcomes of VA PTSD treatment in general and residential programs specifically, making it clear the VA needs to carefully assess and address poor treatment response among Veterans receiving residential and other PTSD treatment. Objectives: The goal of this CDA is to optimize PTSD care by identifying individual- and program-level factors associated with poor treatment response in residential programs, which will greatly enhance the VA's ability to target and improve treatment approaches for these high-need, high-cost individuals. Aim 1 will identify individual- and program-level predictors of treatment response in residential programs nationwide. Aim 2 will further elucidate factors associated with poor PTSD treatment response, using a qualitative approach with patient, provider, and administrator interviews at a VISN 10 program and nationally at 3 high-performing and 3 low-performing programs (based on average symptom change and percent of patients readmitted within 14 days of discharge). Aim 3 will pilot an adaptation of an existing treatment or health services intervention based on findings from the initial study aims, data on treatment practices at high-performing sites, and assessment of feasibility from an expert panel consisting of the mentorship team, operational partners, and frontline staff. Methods: This research will be guided by the theory of Resources, Life Events and Changes in Psychological States. Aim 1 will assess predictors of poor response using multilevel modeling of nationwide clinical information collected by the Northeast Program Evaluation Center. Variables of interest will include individual- level resources and factors such as comorbidities, social contextual resources (e.g. low social support), and program resources such the availability of evidence-based treatments. Aim 2 will utilize qualitative analytic methods to assess individual and program-level predictors of response by interviewing patients and providers. Aim 3 will consist of a feasibility pilot conducted with 60 patients at a VISN 10 residential program for PTSD. Candidate: The PI's long-term goal is to become an independent VA health services investigator wh...