Virtually all those we interviewed expressed a sense of the enormity of change in the marketplace and the span of effects from this change. There is widespread agreement that the serious gaps in “supply side” information on the health system that predated these changes have only grown worse as the system has evolved. These stakeholders recognize the prominent role of market-place strategies in driving change, spurred both by purchasers and by changes in medical practice and technology. They also see considerable instability and geographical diversity in markets. Despite change, fundamental problems, like care for the uninsured, continue, with new problems emerging, like those associated with changes in the physician-patient relationship in a managed care environment. Stakeholders also perceive that emerging provider organizations and managed care models are becoming increasingly complex, with overlapping ownership and contractual linkages among component parts of the health care system. Moreover, provider networks serve diverse managed care products.