As Musk and his critics toss around statistics, here are some points to know about how the government spends $6.8 trillion taxpayer money. The largest chunks of the federal budget go toward mandatory spending. These programs do not need annual outlays approved by Congress. They include: Social Security (about 20%).

Multiple U.S. federal agencies told employees not to respond immediately to a demand by President Donald Trump's adviser Elon Musk to list their accomplishments in the last week or be fired, as a chaotic campaign to cull the bureaucracy pushes forward.

Leaders at defense and intelligence offices were particularly wary of Musk’s demand over the weekend asking workers to outline what they did last week.