PROJECT SUMMARY This advanced-level short course will provide intensive training in innovative approaches for designing and conducting randomized clinical trials (RCTs) of behavioral interventions. Currently there is insufficient evidence from behavioral RCTs to inform public health campaigns, clinical guidelines, and insurance coverage for behavioral interventions. A stronger evidence base will emerge from more rigorous and definitive efficacy and effectiveness trials. In the field of behavioral medicine, the intervention development process is not standardized or accepted as it is for pharmacotherapy and devices. Investigators require didactic training not often included in medical and graduate programs, as well as mentorship, to implement best practices for RCT design and conduct. Greater reliance on interdisciplinary team science and translational research models, and wider adoption of advanced methodologies, will increase the impact of behavioral intervention research. This course is designed for early- to mid-career scientists who are already planning or conducting a behavioral RCT or who are conducting early-stage intervention development research that is expected to lead to an RCT. It is designed to provide a longitudinal learning experience during which learners (hereafter “fellows”) acquire foundational knowledge and apply it to a planned RCT. This hybrid course includes a four-day, in-person meeting at which foundational concepts will be discussed, and five learning communities comprising two faculty members and six fellows will be formed. Each learning community will engage in nine monthly, two-hour video conference calls. Prior to each call, fellows will watch videos or listen to podcasts about selected RCT topics. The program will employ a facilitated peer mentoring model in which two experienced faculty members will work with six fellows, who in turn serve as peer mentors. During the virtual meetings, they will discuss how to apply the didactic content to their planned RCTs. The core faculty members are leading experts in various behavioral intervention research methodologies and have real-world experience conducting behavioral RCTs. Adjunct faculty members and guest speakers will include rising stars who are developing cutting-edge RCT methodologies and staff from funding agencies and payers. Course content will be organized by the NIH Stage Model for Behavioral Interventions and focus on Stages II (efficacy) through V (dissemination and implementation) to complement existing R25 offerings. In short, this course will train the next generation of scientists to design and conduct programmatic, strategically-focused, interdisciplinary behavioral RCTs. In so doing, we will contribute the rigorous evidence needed to change clinical guidelines, practices, and policies.