When federal agencies and programs lack appropriated funding, they experience a funding gap. Under the Antideficiency Act, they must cease operations, except in certain emergency situations or when law authorises continued activity. Failure of the President and Congress to reach agreement on interim or full-year funding measures occasionally has caused government shutdowns. Government shutdowns have necessitated furloughs of several hundred thousand federal employees, required cessation or reduction of many government activities, and affected numerous sectors of the economy. This book discusses the causes, processes, and effects of federal government shutdowns; economic activity during the government shutdown and debt limit brinkmanship; impacts and costs of the October 2013 federal government shutdown; a brief overview of federal funding gaps; and operations of the Department of Defense during a lapse in appropriations.