The health care industry has undergone radical change in Florida and elsewhere in recent years, and further change seems inevitable. Health maintenance organizations (HMOs) have emerged as major providers of health care services, and outright mergers as well as other affiliations among health care providers have become commonplace in Florida and elsewhere.  These changes give rise to many important research issues. For instance, it is important to assess which mergers and alliances best serve the needs of Florida's residents, particularly the State's elderly population.  In addition, the compensation structures within HMOs that best foster cost reduction without sacrificing unduly the quality of delivered care should be identified. It is also important to predict the likely long-run structure of the health care industry in Florida and elsewhere, and to determine which, if any, forms of government intervention in the industry should be considered to supplement the enforcement of state and federal antitrust laws.