In the United States, government shutdowns occur when there is a failure to enact funding legislation to finance the government for its next fiscal year or a temporary funding measure. Ever since a 1980 interpretation of the 1884 Antideficiency Act, a "lapse of appropriation" due to a political impasse on proposed appropriation bills requires that the US federal government curtail agency activities and services, close down non-essential operations, furlough non-essential workers, and only retain essential employees in departments covering the safety of human life or protection of property. Voluntary services may only be accepted when required for the safety of life or property. Shutdowns can also occur within and disrupt state, territorial, and local levels of government.