PROJECT SUMMARY/ABSTRACT This application seeks renewal of support for the University of Pennsylvania’s (Penn’s) postdoctoral training program in health services research (HSR). The program’s overall goal is to train investigators to conduct independent, rigorous, and high-impact HSR and thereby improve the quality, safety, efficiency, and equity of health care organization, financing, and delivery. Our program leverages Penn’s well-established institutions and resources dedicated to producing high-quality and high-impact HSR, including top-tier educational programs, outstanding faculty and mentorship, a robust research infrastructure, and a strong institutional commitment to HSR. Addressing the complex challenges facing the nation’s healthcare system requires diverse perspectives and partnerships across multiple academic disciplines. In recognition of this, we have designed our post-doctoral training program for both clinicians seeking to become clinician-researchers by acquiring HSR skills, as well as PhD-trained economists seeking to apply their methodological expertise to the field of HSR. Our program not only develops these competencies for both trainee groups, but also, by linking clinician- researchers with PhD-trained postdocs in Penn’s collaborative and interdisciplinary HSR training environment, we aim to develop leaders who can build diverse and inclusive investigator teams that combine disciplinary and institutional expertise. Our T32 program will continue to be administered by Penn’s Perelman School of Medicine, which houses one of our training program’s key educational curricula—the Master of Science in Health Policy Research—and will closely collaborate with Penn’s Leonard Davis Institute for Health Economics (LDI), which runs the second key training program component—LDI’s postdoctoral program for health economists. The Perelman School and LDI have a long and robust history of successful collaborations. This program will also continue to draw on additional faculty expertise and mentoring from Penn’s Wharton School, Penn’s School of Nursing, and the Children’s Hospital of Philadelphia. Together these entities are well suited to provide the highest quality training environment to both clinician-researchers and PhD-trained economists seeking to become independent and influential health services researchers. Thus, our HSR training program capitalizes on Penn’s unique strengths and long history in fostering cutting-edge research across its schools and disciplines. Our program’s graduates will have the necessary skills to address the health care delivery system’s most pressing problems and make health care organization and delivery higher quality, safer, more efficient, and equitable.