PROJECT SUMMARY / ABSTRACT Attrition of underrepresented minority (URM) scientists between the PhD and faculty stages presents a major stumbling block to diversify the biomedical workforce. While multiple factors contribute to this attrition, the postdoc stands as a critical step that can define academic career outcomes. Even more than their PhD lab, where a trainee does their postdoc determines their academic productivity and odds of securing a tenure-track position. Unfortunately, preparation for the PhD to postdoc transition is informal, unstructured and variable, and presents a unique set of planning, mentoring, and communication challenges. For URM students, these challenges are compounded, making their attrition much more likely. We propose to adapt and apply the validated professional development strategies of the Yale Ciencia Academy (YCA) to an unattended transition that is impacting faculty diversity: the PhD to postdoc transition. Through training interventions that include practice and modeling, vicarious learning experiences, and peer mentoring interactions, we will make evident the planning, mentoring, and effective communication complexities required for this transition. Specifically, students will (a) craft an individual development plan (IDP) that is specific to the PhD to postdoc transition; (b) master the career planning, mentoring-up and communication skills they need to successfully execute their plan; (c) produce communication materials for use during postdoctoral interviews and grant submissions; and (d) cultivate a network of peer mentors, role models, and advisors that can support them through the transition and beyond. By providing tangible outcomes and skills in career planning, mentoring-up, and communication, we expect the program will enhance participants’ academic and science communication self-efficacy, scientific identity and positive outcome expectations, and result in a postdoctoral placement that aligns with their career goals. A minimum of 16 biomedical URM PhD students will be recruited per year throughout the US for a total of 64 students over four cohorts. To extend the impact of our program, we will turn most of our trainings into free video-based modules with accompanying implementation guides, estimated to impact thousands of additional students. The skills and the know-how developed during this program will allow students to model supportive mentoring environments and effective career development practices as postdocs and ultimately as faculty, contributing to more inclusive academic research environments. In the long term, we expect YCA to increase persistence and the number of URMs in academic research positions.