Managed care was designed to bring stability and balance to healthcare delivery in the United States, but its experience in the legal system has involved only moderate stability and very little balance. There has been a trend toward broad deference to the industry, so that managed care organizations (MCOs) are largely immune from liability. At the same time, some courts have suggested that the entire managed care model rests on sketchy legal ground. Meanwhile, commentators have disagreed on such fundamental questions as whether legal disputes arising under managed care should be resolved according to contract law or tort law. Moreover, the extent to which the Employee Retirement Income Security Act of 1974 (ERISA) governs, or moots, patients’ claims against MCOs has never been entirely clear—and because ERISA controls a vast number of health insurance plans, this legal issue is extremely significant.