CNN  — 

As the co-heads of the newly created Department of Government Efficiency, or DOGE, billionaires Elon Musk and Vivek Ramaswamy are promising to slash at least $2 trillion from the federal budget.

The duo, who are tasked with recommending cuts to the incoming Trump administration as outside advisers, have cited areas they’d like to target. They include the Internal Revenue Service, the Department of Education, the Federal Bureau of Investigation and the Nuclear Regulatory Commission. And they want to take a hard look at foreign aid, defense spending and the inaccurate payments the government sends to Social Security recipients and others.

But taking that big a chunk out of federal spending would be a tall order, experts say. Much of the money supports mandatory programs, which must be funded in accordance with existing laws. These include Social Security and Medicare benefits and interest on the federal debt.

Less than one-third of the federal budget in fiscal year 2024 consisted of discretionary spending, which Congress approves annually. Nearly half of discretionary spending goes toward defense programs, which are a sacred cow for many lawmakers.

“$2 trillion a year is such an absurdly large number, it’s impossible,” said Bobby Kogan, senior director of federal budget policy at the left-leaning Center for American Progress.

Here’s where your taxpayer dollars go:

Three key facts about federal workers

Musk and Ramaswamy have also repeatedly said they could downsize the federal workforce by forcing employees to return to the office, which they hope would prompt many of them to quit.

Fewer than half of federal civilian workers are eligible to telecommute, and those that can still spend a majority of their working hours in their offices.

Both Musk and Ramaswamy have assailed federal workers as bureaucrats who oversee an ever-growing web of regulations.

“The power of the unelected Federal bureaucracy has grown to become an unconstitutional ‘FOURTH BRANCH’ of government!” Musk posted on X earlier this week. “Especially with the creation of their own internal court system, it has become the most powerful branch of government. We must fix this!”

But the federal workforce is about the same as it was 50 years ago, even though the federal government oversees more programs and provides more benefits.

Under former President Bill Clinton, the headcount dropped by more than 400,000 as he sought to “reinvent” the government, according to Elaine Kamarck, founding director of the Brookings Institution’s Center for Effective Public Management. Also, he was able to take advantage of the crumbling of the Soviet Union to trim the Department of Defense. But the September 11 attacks put a halt to the downsizing in 2001, and the government has beefed up its intelligence and homeland security workforces since then.

While many people may think the federal workforce is concentrated in Washington, DC, and the surrounding metro areas, that’s not the case.

“Federal employees are providing services to the public everywhere,” said Max Stier, founding president and CEO of the nonprofit Partnership for Public Service, which advocates for an effective federal government.

This article has been updated with additional information.