What a shutdown means
Past government shutdowns paused nonessential activities in various government departments—for example, national parks and museums have closed. Critical federal functions such as the Postal Service, payment of Social Security benefits, and air traffic control staffing generally were not affected. The scope of these pauses can vary across shutdowns, and each government agency within the affected departments and agencies will publish guidance clearly defining the scope of its activities during a shutdown. Federal shutdowns don’t affect state and local government functions that are not dependent on federal funding.
Shutdowns have occurred more than 20 times since 1976. Unlike a U.S. debt default, a shutdown does not affect the government’s ability to pay its obligations, and, as noted, many critical services continue.