The news of a government shutdown doesn’t always tell Americans what it means when the “shutdown” takes place.

A shutdown is based on the Constitution’s mandate that the Congress pass laws to spend money. If the Congress can’t pass a bill or the President vetoes the bill, the government cannot spend money. Congress used to pass a budget and then 12 different appropriations bills but that process has been breaking down for decades. The last fiscal year without a “continuing resolution” to keep the government running at previous budget levels was 1997.

The government’s fiscal year runs from October 1st to September 30th. Shutdowns can happen at other parts of the year if a continuing resolution did not fund a particular part of the government for a full year.

If Congress does not pass a continuing resolution in time for the President to sign it before midnight, most federal employees who are not considered “essential” would show up at work Tuesday to basically shut their departments down and then be basically laid off.

The U.S. Postal Service will still operate and some services such as passports would continue until their funding runs out. However, national parks and other items like museums would be immediately closed. Also, the District of Columbia could face serious shortfalls because they receive money from Congress.

Senior citizens would continue to receive their social security benefits. Unemployment benefits and food stamps would also continue. Even Obamacare itself would continue because it is considered a “permanent entitlement” like Social Security or Medicaid.

The Food and Drug Administration will have less activity than normal but will continue to watch recalls and investigate unsafe medications. Also the Food Safety and Inspection Service would continue their work related only to food safety.

Federal law prohibits any federal employee from volunteering to work to keep an office or entity open because of the risk they could sue for back wages.