Background: PTSD is the most common mental health disorder among Veterans seeking treatment at Veterans Affairs (VA) hospitals, and more than half of Veterans with PTSD also meet criteria for a substance use disorder (SUD). To address the critical need for PTSD/SUD treatment, members of the investigative team developed Concurrent Treatment of PTSD and Substance Use Disorders Using Prolonged Exposure (COPE), an evidence-based, integrated, trauma-focused treatment identified by the VA as a gold standard of behavioral healthcare. Randomized controlled trials among Veterans demonstrate COPE's efficacy in significantly reducing PTSD and substance use. The majority of Veterans with PTSD/SUD prefer integrated treatment. Significance/Impact: At present, there is a critical shortage of clinicians trained to deliver COPE. Traditional in-person workshops are inefficient and costly. A poll of VA PTSD/SUD Specialists across the country found that 96.9% are interested in receiving COPE training and 99.1% would use a web-based training for COPE if available. A web-based resource for providers is ideal, as it can be rapidly disseminated, is easily accessible, and provides a significant amount of information in a standardized way. This project will directly address this critical gap in provider training to improve the care of Veterans with comorbid PTSD/SUD, enhance treatment delivery using innovative in-session provider assistance tools, and enhance knowledge of cost-benefit of technology-enhanced training. COPEWeb may be particularly useful for providers in rural clinic settings where mental health training is less accessible. This proposal has the potential for high military relevance and an immediate impact on dissemination and uptake of COPE, as well as a long-term impact on the overall health of the millions of Veterans suffering from co-occurring PTSD/SUD. Innovation: A new web-based provider training for COPE will be developed along with a highly innovative provider assistance toolkit to guide clinicians in real-time during sessions to enhance delivery and fidelity to the protocol and reduce provider burden. A panel of national VA experts and dissemination leaders will develop a best practice VA dissemination guideline on disseminating web-based provider trainings. The proposed project has the potential to significantly enhance provider training and increase patient access to evidence-based care. Furthermore, COPEWeb has the potential to serve a novel role in disaster planning to ensure mental health care providers are equipped to address the anticipated post-pandemic needs of Veterans given the rise in post-traumatic stress and alcohol/drug use during the pandemic. Specific Aims: This project aims to 1) develop a new web-based training protocol and innovative delivery aid system to strengthen providers' delivery of COPE to treat Veterans with PTSD/SUD with a high level of fidelity and competence, and 2) compare the COPEWeb training to in-person training on measures of knowledge, satisfaction, and behavior (i.e., fidelity). The cost effectiveness of web-based vs. in-person training will be examined. Methodology: The proposed methods and timeline for the development of COPEWeb are based on the team's prior success developing other widely-used provider training protocols (e.g., PEWeb, CBTIWeb). COPEWeb will be built and refined over the course of three strategic phases: content development, alpha-testing, and beta-testing. Following beta testing, the investigators will compare COPEWeb to in-person training among clinicians. Ongoing assessment will obtain qualitative and quantitative data on measures of provider satisfaction, knowledge, and behavior. Implementation/Next Steps: In collaboration with the investigators' operations partners, VA leadership, and EBP Coordinators, COPEWeb will be rapidly disseminated to mental health providers to increase adoption of evidence-based treatment for PTSD/SUD and improve the quality of mental health care for Veterans and the nation.