What Is the Debt Ceiling and Why Does It Matter?

Debt ceiling battles are nothing new on Capitol Hill: Congress has raised the limit 78 times since 1960. But during the past two decades, what was once a routine vote has become one of the most politically contentious issues that Congress faces. But what is the debt ceiling, and why does it matter?

Ahead, we'll cover key topics including:

  • What is the debt ceiling?
  • Why do markets care?
  • Has this happened before?
  • What impact would a default have on U.S. stocks?
  • What impact would a default have on money market funds?
  • What does this mean for investors who hold U.S. Treasury securities?

What is the debt ceiling?

The debt ceiling is the total amount the U.S. government is authorized by Congress to borrow to meet its existing obligations, including interest payments on Treasury securities. The federal debt is currently $36.1 trillion. The government hit the debt ceiling in January 2025. Since then, the Department of the Treasury has been using accounting maneuvers (referred to as "extraordinary measures") to stay under the U.S. debt limit and continue to pay its obligations, including Social Security and Medicare.

It's not known exactly when the U.S. will reach the "X-date" when it runs out of cash and the extraordinary measures are exhausted. Treasury Secretary Scott Bessent wrote to Congress on May 9th that it was likely to occur in August and urged lawmakers to raise or suspend the debt limit in July, before Congress goes on break.