Hospital emergency departments are a major part of the nation's health care safety net. Of the estimated 119 million visits to U.S. emergency departments in 2006, over 40 percent were paid for by federally-supported programs. These programs, Medicare, Medicaid, and the State Children's Health Insurance Program, are administered by the Department of Health and Human Services (HHS). There have been reports of crowded conditions in emergency departments, often associated with adverse effects on patient quality of care. This book explores the issues in providing emergency medical care, including crowding in emergency hospital departments; emergency response and volunteer health professionals; ambulance providers; and public health and medical preparedness response.