One of the basic responsibilities of Congress is to pass annual appropriations legislation to keep government agencies and programs funded.

Under the Origination Clause of the U.S. Constitution, all bills raising revenue (or spending the government’s money) must begin in the House of Representatives. This clause gives the power of originating spending bills to the body of Congress that the Founding Fathers viewed as the most closely linked to the people: the House of Representatives.

Annual federal spending totaled $4 trillion in fiscal year 2015 — 64.63% of that for mandatory spending programs (Social Security, Medicare, etc.); 29.34% for domestic discretionary spending programs (defense, transportation, environment, education, etc.); and 6.03% for interest on the national debt.

In House and Senate appropriations committees, the funding responsibilities are divided up among 12 subcommittees that cover all the executive branch departments and agencies within the federal government.

Each subcommittee is responsible for an annual appropriations bill, which provides the year’s funding for those agencies and departments. For example, funding for the Federal Motor Carrier Safety Administration (FMCSA) is found in the Transportation, Housing and Urban Development, and Related Agencies bill.

Appropriations bills are often the most politically charged bills of the year, and — more importantly — they are “must pass” bills in order to avoid government shutdowns, so they become very attractive vehicles for other legislative priorities.

While appropriations bills are only permitted by congressional rules to designate funding levels for agencies and programs, policy provisions are often addressed through provisions known as “limitations” or “riders.” These can be actions to stop agency regulations from going forward, such as was included last year to prevent FMCSA from moving forward with a regulation to significantly increase minimum insurance limits.

Congress is supposed to approve a budget by April, and appropriations bills, written to that budget, are supposed to be enacted by the start of the government fiscal year, which is Oct. 1. Unfortunately, in the 21st century Congress, this rarely happens.

What Congress usually does in these situations is pass what are called “continuing resolutions” to keep the government running past the start of the fiscal year until the bills can pass. Sometimes different strategies are needed, and a series of bills can be combined into a “minibus,” or all outstanding appropriations can be combined into an “omnibus” bill.

Currently operating under a continuing resolution and following the Nov. 8 elections, Congress will return for a lame duck session and hopefully finish this important work in November and December.

A few times in the past 20 years, Congress has not passed a continuing resolution or appropriations bills in time, and the government has shut down for a few days or even up to several weeks.

When this happens, nonessential government employees of an agency or department without an appropriation are furloughed, and there is no guarantee that workers will be paid for their time out of work. (However, in past shutdowns, Congress has enacted legislation to ensure that federal employees received their full pay.)

In addition, government-controlled buildings and services of the affected agencies and departments are closed. Government shutdowns have been utilized as an effort to exert leverage to get agreement on controversial issues, but history shows that because shutdowns are so unpopular with the public, the method usually does not produce the desired result.