When federal agencies and programs lack funding after the expiration of full-year or interim appropriations, the agencies and programs experience a funding gap. If funding does not resume in time to continue government operations, then, under the Antideficiency Act, an agency must cease operations, except in certain situations when law authorises continued activity. The criteria that flow from the Antideficiency Act for determining which activities are affected are complex. 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 causes of shutdowns, including the legal framework under which they may occur; processes related to how agencies may plan for the contingency of a shutdown; effects of shutdowns, focusing especially on federal personnel and government operations; and issues related to shutdowns that may be of interest to Congress.