Q&A: US shutdown - all you need to know about the crisis in America

National parks, such as the Grand Canyon in Colorado, and refuse services, have been shut down (Alamy)

Not all government functions will simply evaporate — Social Security cheques will still get mailed, and hospitals will stay open. But many federal agencies will send their employees home, from the Environmental Protection Agency to hundreds of national parks. Here’s a look at how a shutdown will work.

Why is the US government shutting down?

There are wide swaths of the federal government that need to be funded each year in order to operate. If Congress can’t agree on how to fund them, they have to close down. And, right now, Congress can’t agree.

More specifically: each year, the House and Senate are supposed to agree on 12 appropriations bills to fund the federal agencies. Congress has become bad at passing these bills, so in recent years they’ve resorted to stopgap budgets to keep the government funded. The last stopgap passed on 28 March 2013, and ended on 30 September.

In theory, Congress could pass another stopgap. But the Democratic-controlled Senate and Republican-controlled House are at odds over what that stopgap should look like. The House passed a funding bill over the weekend that delayed Obamacare for one year and repealed a tax on medical devices. The Senate rejected that measure. They voted a few more times and still no agreement. So... there is a shutdown.

Does this mean that everyone who works for the federal government must go home?

Not exactly. The laws and regulations governing shutdowns separate federal workers into “essential” and “non-essential.” If a shutdown hits, the essential workers stick around, without pay. The non-essential workers go home after a half-day of preparing to close shop.

Which parts of government stay open?

There are a whole bunch of key government functions that carry on, including anything related to national security, public safety, or programmes written into permanent law (like Social Security).

Do these “essential” employees who keep working get paid?

The 1.3 million or so “essential” civilian employees could see their paycheques delayed. They should, however, receive retroactive pay if and when Congress decides to fund the government again.

The 1.4 million active-service military members will get paid no matter how long the shutdown lasts.

So which parts of government shut down?

Everything else, basically.

How many federal employees would be affected by a shutdown?

The government estimated that about 800,000 federal workers would get sent home. That leaves about 1.3 million “essential” federal workers, 1.4 million active-duty military members, 500,000 Postal Service workers, and other employees in independently funded agencies who are continuing to work.

Was the government even prepared for a shutdown?

Maybe. The Office of Management and Budget asked federal agencies to develop contingency plans for a shutdown. But chaos is always possible.

Which parts of the economy would be most affected?

The local economy around Washington, DC is expected to lose about $200m in economic activity for each day the government is shut down.

Economist Mark Zandi has estimated that a short shutdown, which would send more than 800,000 federal workers home, could shave about 0.3 percentage points off economic growth in the fourth quarter of 2013. A more extended shutdown could do even more damage.

Would a shutdown stop Obamacare from happening?

No. The key parts of Obamacare rely on mandatory spending that isn’t affected by a shutdown.

How do you end a government shutdown?

Congress needs to pass a bill (or bills) to fund the government, and the White House has to sign them.

How often has the government shut down before?

Since 1976, there have been 17 different government shutdowns. The longest came in 1995-96 and lasted 21 days.

© The Washington Post