We are witnessing an unprecedented transformation of the health care industry. There has been a rapid growth in jobs and an explosion in the number of start-ups. There are new types of insurance companies such as Oscar; novel provider organizations such as OneMedical, IoraHealth, and ChenMed; and new health information technology companies such as Castlight, Vital, and WellFrame that aim to use technology to improve care and value. Physicians and nurses are being called upon to lead these new health care enterprises — and are assuming a higher level of influence in the business of health care than ever before.