Between 2000 and 2015 the proportion of US hospitals with more than fifty beds that had palliative care programs tripled, from 25 percent to 75 percent. The rapid adoption of this high-value program, which is voluntary and runs counter to the dominant culture in US hospitals, was catalyzed by tens of millions of dollars in philanthropic support for innovation, dissemination, and professionalization in the palliative care field. We describe the dissemination strategies of the Center to Advance Palliative Care in the context of the principles of social entrepreneurship, and we provide an in-depth look at its hallmark training initiative, Palliative Care Leadership Centers. Over 1,240 hospital palliative care teams have trained at the Leadership Centers to date, with 80 percent of them instituting palliative care services within two years. We conclude with lessons learned about the role of purposeful technical assistance in promoting the rapid diffusion of high-value health care innovation.