This paper reviews information from surveys and focus group studies about how consumers define high-quality care and the types of information they want when making decisions about which health plan to join. The authors also interviewed consumer advocacy groups and persons responsible for disseminating health plan information to Medicare enrollees in various types of managed care plans to learn about the types of plan information that Medicare enrollees most often request. They describe the types of information that should be made available to consumers and the challenges involved in making this information understandable and useful.