WASHINGTON - If Congress doesn't pass a new spending bill in the next week, the federal government will shut down on Oct. 1.
That is, 41% of it will.
An estimated 59% of non-defense federal employees would be exempt from the shutdown and would go to work as usual, according to a USA TODAY analysis of 119 shutdown contingency plans filed with the Office of Management and Budget.
Among them: political appointees, law enforcement, most overseas foreign service officers and anyone else deemed necessary for health or safety of people or property.
That last category can account for a broad cross-section of federal employees, because positions that support a key function - such as information technology, security or even legal help - are also protected. Even a receptionist responsible for picking up sensitive mail deliveries could be considered essential and exempted from furlough.
Maintaining an agency website usually isn't a necessary function, although the Office of Management and Budget said this month that the IRS website may be necessary "to allow for tax filings and tax collection." That's one key difference from the last government shutdown in 1996, when agencies were less reliant on the Web.
"Where those lines are drawn can change from time to time," said Ray Natter, a former deputy chief counsel of the Office of the Comptroller of the Currency. And the two government agencies responsible for interpreting the law on who's essential and who's not - the Office of Legal Counsel and the Comptroller General - often give inconsistent advice, he said.
Agencies that don't operate on an annual appropriation from Congress also will continue to operate normally. That would include the Postal Service, the Patent and Trademark Office and the Federal Highway Administration. A Census Bureau statistician working on a project in Bangladesh is paid outside of the annual budget and could continue to work.
Meteorologists at the National Weather Service would continue to issue weather forecasts because they're necessary for aviation safety. But ocean and atmospheric scientists who don't produce daily forecasts would also continue to work in order to maintain "crucial long-term historical climate records," according to the Department of Commerce's plan.
At the Consumer Product Safety Commission, the commissioners would continue to work because they're appointed by the president. But the commission's contingency plan also calls for some of the agency's lawyers to go to work, so they can provide "timely and accurate legal advice" to the commissioners about what they can and can't do during a shutdown.
About 65% of Washington-based State Department employees - and 10% of overseas-based employees - would be furloughed. Passport offices would be closed, but any State Department official deemed necessary for the president to carry out his treaty-making responsibilities under the Constitution would come to work. And foreign nationals employed by the State Department may be subject to their country's labor laws, which may not allow an unpaid furlough.
For most federal agencies, almost all employees would work at least a half-day after a shutdown to lock their filing cabinets, update their voicemail and fill out time cards. When the shutdown is over, agencies might take a half-day to ramp back up before opening their doors to the public.
USA TODAY looked at the most recent contingency plans for 339 federal departments, agencies and offices, all filed in 2011 when the government last faced the possibility of a shutdown. The analysis does not include the District of Columbia and many smaller agencies that did not submit a report or those that did not provide personnel figures in their reports.
Also not included: the Department of Defense. "While military personnel would continue in a normal duty status, a large number of our civilian employees would be temporarily furloughed," Deputy Secretary of Defense Ashton Carter said in a memo to employees Monday. Just how many would be furloughed is unclear; Carter said the department is still updating its contingency plan.
At the White House, 365 staffers would report to work and 1,166 would be furloughed during a shutdown.
Natter noted that the Anti-Deficiency Act, the 129-year-old law that forces the government to shut down without an appropriation from Congress, also makes it illegal for furloughed workers to volunteer - even though many end up getting paid whether they work for not. "It really ought to be rewritten to be more relevant for the 21st century," he said.
Roy Meyers, a professor at the University of Maryland-Baltimore who teaches federal budgeting, said he's not surprised to see agencies use as much flexibility as they can get away with.
"To the extent that agencies are taking advantage of the vague guidance OMB has given them, it doesn't bother me a bit," he said. "What the agencies are being told to do (is) an asinine thing."
(Copyright 2013 USA Today. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)