Evidence-based psychotherapies (EBP) are the most effective treatments for posttraumatic stress disorder (PTSD; APA, 2017; VA/DoD, 2017) and yet remain significantly underutilized (Hundt et al., 2017; Kehle-Forbes et al., 2016). Patient level barriers to EBP use including patient knowledge about EBPs, stigma, and concerns about treatment effectiveness or treatment demands (e.g., Hundt et al., 2015). Interventions that increase the rate of EBP initiation in Veterans with PTSD can substantially improve symptom burden, functioning, and quality of life (APA, 2017). Direct to consumer (DTC) marketing strategies, in which a service or product is advertised directly to the end user rather than a health care provider, are frequently used and highly effective at driving demand for psychotropic medications (e.g., Avery et al., 2012; Woloshin et al., 2001). DTC marketing may be particularly effective for EBPs because advertisements can directly target some of the primary barriers to EBP use. However, the limited existing studies on DTC marketing for mental health have focused on patient- reported intentions to engage in treatment, rather than actual therapy-seeking behaviors (e.g., Brecht et al., 2017; Gallo et al., 2013). Second, no studies have systematically compared different DTC marketing messages. This is an important omission because not all message types work for all products and for all consumers (Belch & Belch, 2017; Ogivy, 1985). Third, most prior studies of DTC advertising for psychotherapy have presented their messaging to the general population, rather than selecting for participants who need psychotherapy, which limits the applicability of their conclusions to target populations, and no studies have specifically focused on Veterans or those with PTSD. Guided by the Theory of Planned Behavior (TPB; Ajzen, 1991) and Veteran and provider stakeholder feedback, the current study proposes to develop and test different versions of DTC advertising messages aimed at increasing engagement in EBPs for PTSD. Although VA has invested considerable resources in advertising campaigns for mental health, PTSD education and outreach materials, no research has examined which strategies would be most effective at increasing Veteran initiation of psychotherapy. Having this information would help VA focus its limited financial resources on the most effective DTC advertising strategies and messages, which has the potential to engage more Veterans in the most effective treatments and reduce the burden of untreated PTSD (e.g., Zatzick et al., 1997; 2008; Kessler, 2000). This proposal aligns with the 2019 VA priorities emphasizing research on high priority mental health conditions, such as PTSD, and increasing return on investment in EBP training and increasing efficiency by facilitating uptake of the most effective treatments for PTSD. In pilot work, Veterans, family members, providers, and Veterans’ Service Organization members provided feedback on which DTC adver...