Hospital-based Emergency Departments (EDs) are required to stabilise patients with emergent conditions regardless of the patients' ability to pay as a requirement of the Emergency Medical Treatment and Active Labor Act (EMTALA). Given this requirement, EDs play an important part in the health care safety net by serving the uninsured, the underserved, and those enrolled in Medicaid. This book describes EDs and the role they play in the health care delivery system. It also discusses the federal role and interest in supporting emergency care.