The US federal government has shut down after Republican and Democratic lawmakers failed to resolve a budget standoff.
The impasse affects the funding of government operations through October and beyond and is poised to cause widespread disruption for Americans in areas ranging from air travel to zoo visits.
The political gridlock is also expected to put 40% of the federal workforce – about 800,000 people – on unpaid leave.
Here's how its impact will be felt across the country.
Your next flight
A federal shutdown will hit flyers in a variety of ways, potentially leading to long security queues, and delays caused by unpaid air traffic controllers choosing to stay home rather than work for free.
Air traffic control and Transportation Safety Administration (TSA) workers are considered essential, so they will continue to go to work in the event of a shutdown. However, they will not be paid until the shutdown ends. During the last shutdown in 2018-2019, these workers increasingly began to call in sick, leading to airport delays.
Impact will also be felt by Americans planning to travel abroad, with US passport agencies warning that it could take longer than usual to process travel documents.
No work - or pay - for federal workers
Federal employees will be among the hardest hit, as they will not receive any pay while the shutdown continues.
Some workers may choose to take second jobs, as they have during previous shutdowns. Employees that are not deemed to be essential will be forced to stay home. In the past, these workers have then been paid retrospectively.
Several agencies, such as the Centers for Disease Control and Prevention and the National Institutes of Health, are likely to furlough many workers, affecting ongoing research and experiments already in progress.
President Trump, who has slashed government spending and cut federal jobs since taking office, warned that a shutdown could accelerate further layoffs and allow him to cut services and programs he says are important to Democrats.
Contractors, who work for federal agencies but are not directly employed by the government, will miss out on work, too.
National Parks with no staff
Federal lands, including National Parks and National Forests, have been closed off to visitors during past shutdowns due to ranger staff being absent.
During the last shutdown, the Trump administration left the parks open but with few to no federal workers there. According to park advocates, this led to vandalism, as visitors disrespected protected landscapes and historical sites.
A group of more than 40 former park superintendents has urged the White House to completely close parks in the event of a shutdown.
Visit to the zoo
Washington DC's Smithsonian Institution museums will stay open until at least October 6, thanks to funds from previous years. However, popular animal streaming webcams will be shut down as deemed non-essential by zoo staff.
Health care for the elderly and poor
While Medicare and Medicaid will continue, staffing shortages could lead to interruptions. Emergency disaster relief efforts are also expected to be affected, alongside potential funding shortages for food assistance programs.
