Debt ceiling.

In plain English

The debt ceiling is a statutory limit on total federal borrowing, so raising it does not approve new spending, it lets the Treasury finance spending Congress already voted for. When the limit binds, the Treasury uses accounting steps often called extraordinary measures to keep paying obligations for a while. Once those run out, the government can only spend the cash it takes in, which forces choices among payments that are all legally owed. The limit is set in dollars by statute, so the current figure comes from Congress and the Treasury rather than from any market. Most countries control borrowing through the budget itself and have no separate ceiling.

01Why it matters

A standoff over the ceiling can delay federal payments and rattle the market for Treasury securities, which is the benchmark for mortgage and consumer loan pricing, so the effects reach far beyond federal employees.

02The math, step by step

Say the ceiling is $40 trillion and outstanding debt reaches $39.9 trillion. The Treasury has $100 billion of borrowing room. If the government runs a $150 billion gap that month between cash in and cash out, that room is gone in roughly three weeks and payments must be prioritized.

Illustrative example. The amounts here are hypothetical, chosen to show how the math works, not real quoted rates or figures.

03What this is NOT

04Receipts

Every figure on this page is sourced to a primary document. Tap to open the original.