Until recently, many Americans have been satisfied with their health care and the insurance system that pays for it. Since the early 1990s, however, concerns have arisen about the uneven distribution of medical care and its spiraling costs. Systems of managed care have evolved rapidly in the belief that they ensure that care is comprehensive, coordinated, and cost-effective. Reforms in health care legislated by individual states and at the federal level have spurred growth of managed care and profoundly impacted medical practice. Many hospitals have closed or merged with one another. Consumers have complained about premature discharge from institutions, inconvenience of medical services, changes in the physician- patient relationship, and insufficient access to specialists for treatment of complicated conditions. Managed care plans have competed primarily on the basis of price rather than quality. Most have objected to outcome measures that focus on whether patient health and function improve as a result of treatment. Extensive changes in the health care environment have confronted practitioners with practical and ethical dilemmas.