Posttraumatic stress disorder (PTSD) clinics in the Department of Veterans Affairs (VA) often provide psychoeducational or skill-building groups to prepare veterans for trauma-focused PTSD treatments. However, there has been limited evaluation of the effectiveness of this phase-based approach for treatment engagement and symptom reduction. Participants included 575 veterans seeking treatment for PTSD whose treatment outcomes were assessed in a VA outpatient PTSD clinic staffed by mental health professionals and trainees. Participants completed self-report measures of baseline characteristics and psychiatric symptoms as part of routine PTSD clinic treatment. We tested the association of preparatory group treatment with engagement in and treatment response to subsequent trauma-focused psychotherapies, cognitive processing therapy (CPT) and prolonged exposure therapy (PE), which are designated by VA as evidence-based psychotherapies (EBP). Following participation in preparatory treatments, 94/391 (24%) of veterans engaged in a subsequent trauma-focused EBP (CPT or PE). Relative to patients who had previously completed a preparatory group, patients initiating a trauma-focused EBP without having first attended preparatory PTSD treatment had similar rates of trauma-focused EBP completion and better treatment response, as measured by decreases on the PTSD Checklist for Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5; PCL-5), F(1, 3009) = 10.89, p = .001, and Patient Health Questionnaire 9 measure of depressive symptoms F(1, 3688) = 6.74, p = .010. Overall, veterans reported greater symptom reduction when engaging in trauma-focused EBP directly, without having previously attended a preparatory group. These data support veteran engagement in trauma-focused EBPs for PTSD without first being encouraged to complete psychoeducational or skill-building groups. (PsycInfo Database Record (c) 2021 APA, all rights reserved).