This paper compares the Medicare prospective payment system (PPS) to four all-payer rate-setting systems that operated under HCFA waiver authority. The study examines the experience of Medicare, Medicaid, and commercial insurers under the two approaches. Data from several American Hospital Association surveys and from Medicaid 2082 report forms are analyzed. The paper concludes that the all-payer waiver programs have been as successful as PPS in controlling the rate of growth in Medicare costs. In addition, Medicaid programs are more successful in controlling their outlays in all-payer rate-setting environments than when they “go alone.” Finally, there is no evidence to suggest that hospitals can increase charges in response to greater financial need under either PPS or the state waivers. Nevertheless, it appears that commercial insurers are better able to compete with Blue Cross plans in all-payer rate-setting states than elsewhere.