Debt ceiling FAQs: What you need to know

Ultimately, if lawmakers fail to raise the ceiling this year, they will have two choices, both awful.

They could either cut spending or raise taxes by several hundred billion dollars just to get through Sept. 30, which is the end of the fiscal year. Or they could acknowledge that the country would be unable to pay what it owes in full and the United States could effectively default on some of its obligations.

The first option would be impossible to execute without serious economic repercussions.

And the second option could cripple the economy and send world markets into a tailspin.

"Not only the default but efforts to resolve it would arguably have negative repercussions on both domestic and international financial markets and economies," according to the CRS.