The Emergency Medical Treatment and Active Labor Act (EMTALA) was passed by the US Congress in 1986 as part of the Consolidated Omnibus Reconciliation Act (COBRA), much of which dealt with Medicare issues. The law's initial intent was to ensure patient access to emergency medical care and to prevent the practice of patient dumping, in which uninsured patients were transferred, solely for financial reasons, from private to public hospitals without consideration of their medical condition or stability for the transfer. Although only 4 pages in length and barely noticed at the time, EMTALA has created a storm of controversy over the ensuing 15 years, and it is now considered one of the most comprehensive laws guaranteeing nondiscriminatory access to emergency medical care and thus to the health care system. Even though its initial language covered the care of emergency medical conditions, through interpretations by the Health Care Financing Administration (HCFA) (now known as the Centers for Medicare and Medicaid Services), the body that oversees EMTALA enforcement, as well as various court decisions, the statute now potentially applies to virtually all aspects of patient care in the hospital setting. Thus, all physicians on the hospital staff, not just emergency physicians, need to be familiar with its general requirements. This article summarizes the historical context of EMTALA and discusses the requirements of the statute both in the law's original language and in the subsequent interpretations by HCFA and the courts. It includes discussions of on-call physician responsibilities under the statute, penalties, and enforcement procedures. The emphasis is on the impact of the statute--not just on the emergency care of patients but on the hospital and its medical staff.