The authors review the evolution of the emergency medicine literature regarding emergency department (ED) use and access to care over the past 20 years. They discuss the impact of cost containment and the emergence of managed care on prevailing views of ED utilization. In the 1980s, the characterization of "nonurgent ED visits" as "inappropriate" and high ED charges led to the targeting of non-emergency ED care as a potential source of savings. During the 1990s the literature reveals multiple attempts to identify "inappropriate" ED visits and to develop strategies to triage these visits away from the ED. By the late 1990s, demonstration of the risks of denying emergency care and more sophisticated analyses of actual costs led to reconsideration of initiatives to limit access to ED care and renewed focus on the critical role of the ED as a safety net provider. In recent years, "de facto" denials of emergency care due to long ED waiting times and other adverse consequences of ED crowding have begun to dominate the emergency medicine health services literature.