US Treasury Debt Maturing in the Next 12 Months

$2.95T of fixed-rate notes and bonds mature between October 2026 and September 2027, at an average coupon of 2.98%, plus $575.8B of TIPS and floating-rate notes. On top of that, the $7.12T of bills outstanding on 2026-09-30 all mature within a year. Bills are refinanced as they fall due, so the bills maturing over a year add up to more than that stock: $2.60T of bills matured in September 2026 alone.

Rolling over means paying a maturing security with the cash raised by selling a new one. Treasury pays maturing bills, notes and bonds out of its cash account and refills it at auction, so most maturing debt is replaced rather than paid off; only net new issuance adds to the debt. In September 2026, $2.60T of bills matured and $2.47T of new bills were issued; across all marketable securities, net new borrowing was +$7.3B (Daily Treasury Statement, face value).

Only when the new debt yields more than the maturing debt pays. The fixed-rate notes and bonds maturing over the next 12 months carry an average coupon of 2.98%; the bills outstanding carry 3.76%. Refinancing all $2.95T of those notes and bonds at the 2-year yield (4.84% on 2026-10-05) would change annual interest by +$54.7B. Rolling the $7.12T of bills at the 3-month yield (4.22% on 2026-10-05) would change annual interest by +$32.6B. These are estimates under one assumption: the whole amount is refinanced at a single reference yield. Treasury chooses the actual mix of maturities, and TIPS and floating-rate notes are left out, so they are not a forecast of the interest bill.

The monthly debt statement lists only the securities outstanding on its record date (2026-09-30). Every bill auctioned after that date is missing, so a month-by-month bill column would shrink toward zero further out and read as if maturities were falling. Bills are shown as one stock instead: $7.12T at an average yield of 3.76%, all due within a year.