Traditional focus areas of medical education are insufficient for preparing future clinicians to function well in the rapidly evolving US health care system. In response, many medical schools and residency programs are integrating into their curricula health systems science (HSS), which includes health care policy, public and population health, interprofessional collaboration, value-based care, health system improvement, and systems thinking. To illustrate the value of HSS, the authors draw upon their experiences as a medical student immersed in HSS and as an educator facilitating students' cultivation of HSS skills. The Need for Health Systems Science US health care delivery systems are rapidly and extensively changing. A significant component of this change concerns organizational structures and processes, such as shifting reimbursement models towards value-based care, increasing the use of care coordinators, and implementing patient-centered medical homes. 1-3 Yet there has also been a concomitant transformation in the outlook of physicians, who are becoming increasingly aware, for instance, that what occurs outside of the clinic or hospital and in a patient's community has a significant impact on health. As these changes require physicians to view their role and contribution to patient care in a new and different way, medical schools and residencies are faced with the corresponding challenge of changing the way students and residents are educated. For nearly a century, medical education has focused on the basic and clinical sciences, 4 but this paradigm has been changing with the emergence of health systems science (HSS). This change started in the 1990s, when increasing evidence of the high incidence of medical errors catalyzed a movement to improve care delivery models. 5-7 In 1999, the Accreditation Council for Graduate Medical Education and the American Board of Medical Specialties adopted systems-based practice as one of the 6 core competencies in both undergraduate and graduate medical education. 8 Medical schools slowly began to integrate quality improvement, 9,10 interprofessional education and collaboration, and social determinants of health into curricula, while residency programs increased their focus on quality improvement and patient safety. 11,12 However, by 2012, these systems