SUMMARY This new proposal seeks continuing support for a proven and thriving T32 Molecular Biophysics Predoctoral Training Program at the University of Colorado, Boulder (CU), currently in its 19th year. The goal of the Biophysics Training Program is to provide exceptional training to a diverse cohort of promising trainees, thereby preparing them for leading-edge research careers at the interface of Biology, Chemistry, Engineering and Physics – or for a broad range of other careers. The 39 training faculty include internationally recognized established investigators and rising young stars from 5 PhD-granting departments: Biochemistry, Chemical & Biological Engineering, Chemistry, Molecular, Cellular & Developmental Biology, and Physics. These faculty and their students use state-of-the-art biophysical approaches to elucidate fundamental aspects of macromolecular structure, dynamics, mechanism, and regulation in systems ranging from single molecules to live cells, with direct relevance to human health. Biophysics is one of the core areas of research on the Boulder campus. Of the 39 training faculty, 22 were hired since the program began, including 10 in the last 5 years. The Biophysics Training Program has been a key driving force behind this growth. The training program, jointly supported by NIH and CU Boulder funds, has established a thriving biophysical community with extensive collaborations and large numbers of joint between biophysicists in different laboratories and departments. Moreover, the program provides highly robust, innovative training for predoctoral students of biophysics, ensuring they receive a broad, interdisciplinary foundation needed for current and future success. The newly enhanced training program combines successful features of the existing program with new elements designed to further increase program diversity and prepare students to effectively navigate the constantly evolving modern workforce. Trainees focus on their home PhD program in year 1, then are appointed as Biophysics trainees in years 2-3 of their graduate studies. Required program elements include core Biophysics courses and training in Responsible Conduct of Research (RCR) and Rigor and Reproducibility (R&R). An array of other program activities, many newly added, provide training in critical thinking, self-efficacy, technical expertise, social proficiency, ethical grounding, sound scientific method, professional skills, teamwork, and leadership skills. The Biophysics trainees, faculty, courses and other program elements are regularly assessed to enable timely, effective responses to excellence and challenges as they arise. Strong outcomes indicate that the program provides highly effective training and support to Biophysics trainees, as demonstrated by 1) recruitment of high quality students and faculty, 2) increased participation by underrepresented groups, 3) strong trainee publication, graduation, and career placement rates, 4) extensive collaborati...