ABSTRACT This application from the University of California, San Francisco (UCSF) seeks continuation of funding for the Learning for Early Careers in Addiction and Diversity (LEAD) for clinical researchers. Historically underrepresented racial and ethnic minoritized groups (URGs) experience personal and institutional-level barriers that may hinder the progression of their academic career, including obtaining independent NIH research funding. Although all new investigators face difficulty securing NIH funding, and efforts are being made at the NIH to address the challenges experienced by URGs, disparities persist. The overarching goal of LEAD is to support the career advancement of URG scholars to increase diversity in NIH funding. The program continues its mission to provide training to postdoctoral fellows and assistant professors from URGs with the primary goal of increasing the number of NIH-funded URGs who conduct NIH-supported substance use and substance use disorder (SUD) research. LEAD builds on the platform of the National Institute on Drug Abuse (NIDA) Clinical Trials Network (CTN), a network of scientists and healthcare organizations that offers a broad infrastructure for multisite testing of science-based SUD therapies. During the next five years, LEAD will bring innovation by enhancing mentor training for both scholars and mentors to increase effective mentoring of URG trainees. Specific aims are to: 1) Match trainee scholars with senior scientists in the CTN who provide scientific mentoring, sponsorship, and professional guidance; 2) fund pilot studies to provide Scholars with preliminary data to support subsequent NIH applications; 3) assist Scholars in developing grant-writing skills and submitting competitive NIH applications during the LEAD training period; 4) offer training in cultural tailoring of evidence-based treatments and implementation research methods; 5) enhance skills for successful mentoring; and 6) foster a networking structure to build relationships with leading experts in SUD clinical trials research. Scholars participate in 3 years of training, including an annual 4-week summer intensive program of courses and workshops at UCSF, mentoring and training during the academic year, and participation in CTN national research and training meetings. Scholars are matched with CTN senior investigators who mentor them through the 3-year training period as well as with a Diversity Advisor and a separate UCSF Mentor. A successful NIH award for research or career development is the key measurable outcome for participating Scholars. The program addresses the need for URG investigators who have expertise in conducting SUD treatment research that impacts healthcare policy and practice. The long-term goals address disparities in NIH funding for URGs and diversity of the scientific workforce in the addictions field.