Enterprise liability means holding hospitals or health plans responsible for patient injuries from physician care. This reform seeks better prevention of injury and more efficient insurance. Systems can do more than individuals to improve patient safety, but first practitioners and institutions must combine into functioning systems, which is not happening in today's medical markets, contrary to mid-1990s expectations. Liability change needs to follow rather than lead market changes. For now, public policy should promote injury prevention in other ways--as a demanding purchaser, a promulgator of performance standards, a funder of research and development, and a communicator of information to patients and health plan enrollees. (Medical Malpractice and the U.S. Health Care System, edited by William M. Sage and Rogan Kersh, Cambridge University Press, pp219-244 (2006).)