A government shutdown will have far-reaching consequences for some, but minimal impact on others.
Mail will still be delivered. Social Security and Medicare benefits will continue to flow.
But vacationers will be turned away from national parks and Smithsonian museums. Low-to-moderate income borrowers and first-time homebuyers seeking government-backed mortgages could face delays.
Here is a look at how services are and are not being affected since Congress failed to reach an agreement averting a government shutdown.
Federal air traffic controllers remain on the job and airport screeners will keep funneling passengers through security checkpoints. Federal inspectors will continue enforcing safety rules.
Social Security and Medicare benefits will keep coming, but there could be delays in processing new disability applications. Unemployment benefits will still go out.
Federal courts will continue operating normally for about 10 business days after the start of a shutdown, roughly until the middle of October. If the shutdown continues, the judiciary will have to begin furloughs of employees whose work is not considered essential. But cases will continue to be heard.
Deliveries will continue as usual because the U.S. Postal Service receives no tax dollars for day-to-day operations. It relies on income from stamps and other postal fees to keep running.
All national parks will be closed, as will the Smithsonian museums, including the National Zoo in Washington. Visitors using overnight campgrounds or other park facilities will be given 48 hours to make alternate arrangements and leave the park. Among the visitor centers that will be closed: the Statue of Liberty and Ellis Island in New York, Independence Hall in Philadelphia, Alcatraz Island near San Francisco and the Washington Monument.
Many low-to-moderate incomes borrowers and first-time homebuyers seeking government-backed mortgages could face delays during the shutdown. The Federal Housing Administration, which guarantees about 30 percent of home mortgages, won't underwrite or approve any new loans during the shutdown. Action on government-backed loans to small businesses will be suspended.
The majority of the Department of Homeland Security's employees are expected to stay on the job, including uniformed agents and officers at the country's borders and ports of entry, members of the Coast Guard, Transportation Security Administration officers, Secret Service personnel and other law enforcement agents and officers. U.S. Citizenship and Immigration Services employees will continue to process green card applications.
The military's 1.4 million active duty personnel will stay on duty and still be paid on time as a result of legislation passed by Congress and signed by President Obama. About half of the Defense Department's 800,000 civilian employees will be furloughed.
All 116 federal prisons will remain open, and criminal litigation will proceed.
Most services offered through the Department of Veterans Affairs will continue because lawmakers approve money one year in advance for the VA's health programs. Veterans will still be able to visit hospitals for inpatient care, get mental health counseling at vet centers or get prescriptions filled at VA health clinics. Operators will still staff the crisis hotline and claims workers will still process payments to cover disability and pension benefits. But those veterans appealing the denial of disability benefits to the Board of Veterans Appeals will have to wait longer for a decision because the board will not issue any decisions during a shutdown.