WASHINGTON -- If Congress doesn't reach a deal on funding the federal government by midnight Monday, agencies will begin to suspend many services and programs that Americans have come to want and need.
The new fiscal year begins Tuesday, but without an annual appropriation the 18 cabinet-level agencies will begin closing programs, offices and services while informing hundreds of thousands of employees to stay home from work.
Some key parts of the government won't actually shut down -- national security, law enforcement, public safety and medical care will continue.
The biggest streams of federal funds to Long Island will continue flowing -- Social Security payments, Medicare and Medicaid reimbursements to doctors and hospitals, and most social safety net programs.
And already obligated FEMA disaster funds and Community Development Block Grant money will continue to be available for superstorm Sandy recovery projects, although it's not clear whether administrative staff would still be on the job.
Many of the nation's 2.1 million federal employees would be furloughed without pay, their work left undone or delayed, affecting many Americans and businesses who need permits and other official services.
Those furloughs would hit many of the 8,100 civilian federal employees on Long Island.
With House Republicans and Senate Democrats at loggerheads this weekend, a short shutdown appeared increasingly likely.
The longer a government shutdown goes on, the worse it will get. As money from previous appropriations and other sources runs out, agencies will begin curtailing an increasing number of services and furloughing more staff.
Veterans benefits could begin to run out. Funding for poor families, the elderly and the disabled could dry up. Payments to federal contractors for their work could be delayed.
Since the 1970s, congressional failure to fund the government has caused shutdowns 17 times. The most recent and longest came in 1995-96, when congressional Republicans and President Bill Clinton deadlocked on funding, shutting the government down for 21 days. That led to a political backlash against the GOP.
The expectations of what a shutdown would mean are largely drawn from that experience and agency contingency plans released Friday.
Here's how a government shutdown would affect federal programs that serve Long Island:
Hard-won federal money for superstorm Sandy recovery, including Federal Emergency Management Agency disaster funds and Community Development Block Grants, still would be available if previously approved, contingency plans show. But no new block grants would be made, officials said.
Sen. Kirsten Gillibrand (D-N.Y.) also said she's concerned that too many staff members would be furloughed. On Friday, she wrote federal agencies urging them to ensure enough personnel would still be on the job to help New Yorkers struggling to get back into their homes.
The military would continue to operate, including in Afghanistan and other outposts. Other essential services would also continue: border patrols; protection of federal lands and property; law enforcement, and guarding federal prisons.
But military personnel would serve without pay. And 400,000 civilian employees at the Defense Department would be furloughed.
Air-traffic controllers, Transportation Security Administration workers who screen passengers and other transportation safety work would continue. So would activities to preserve health and safety such as food inspections and oversight of hazardous materials. Background checks for gun purchases would continue.
But many of the functions of these agencies would be suspended: processing of permits for alcohol, tobacco and explosives, and recruiting and hiring of federal law enforcement officials, such as border guards.
Social Security checks, which provide the biggest stream of direct federal funding to Long Islanders, would continue to be sent out.
But local offices, including those in Freeport, Mineola and Melville, are expected to be closed. Many agency staffers -- about 200 on Long Island in 2011 -- would be furloughed. That means no staff to field questions, make changes in status or hear appeals.
MEDICARE AND MEDICAID
Payments to doctors and hospitals under the health care programs for senior citizens and lower-income residents -- the second-largest stream of federal money to Long Island -- would continue.
But with some of the roughly 140 employees on Long Island in 2011 furloughed, people newly eligible for the programs are expected to see delays in enrolling. As a result, Janine Logan, a spokeswoman for the Nassau-Suffolk Hospital Council, said local hospitals might have to develop contingency plans.
AFFORDABLE CARE ACT
Enrollment in the new health care marketplaces, or exchanges, is scheduled to start Tuesday, the day the federal government might shut down. Much of the act, however, is already funded and would go forward.
"Many of the core parts of the health care law are funded through mandatory appropriations and wouldn't be affected," said Gary Cohen, the Health and Human Services Department official overseeing the health care rollout.
OTHER HEALTH CARE
Already funded research would continue, and Veterans Affairs hospitals, such as the Northport VA Medical Center, would continue to operate.
But the Centers for Disease Control and Prevention would stop disease surveillance, and would be unable to share information about the spread of the flu, AIDS and other diseases.
SOCIAL SAFETY NET
Many social welfare programs are expected to continue, including food stamps, aid to families and children, most Head Start grants, assistance for the elderly and disabled, and subsidies for housing.
First-quarter funding for welfare block grants would be delayed because the shutdown starts on the first day of the new fiscal year. Most states, however, have funds to continue the programs.
VISAS AND PASSPORTS
The State Department would continue to process applications for visas and passports, either for U.S. citizens or foreigners, because the services are paid for by fees, not tax dollars.
Federal courts are expected to continue operation, based on funds the judicial system has collected from previous years and fees it charges. But some court employees would be furloughed, and the work of bankruptcy courts would be suspended during the shutdown. The Justice Department also would curtail civil cases.
Sagamore Hill National Historic Site, Fire Island National Seashore and Gateway National Recreation Area would close.
Amy Verone, Sagamore Hill's chief of cultural resources, said the Oyster Bay home of President Teddy Roosevelt closed in the government shutdown of 1995. The impact on the public would be less for Sagamore Hill this time because the Roosevelt home is closed for renovation, although visitors still come to the grounds. But it would mean unpaid time off for the 17 staff members.