$31.83T of marketable Treasury debt is outstanding (MSPD Table 3, 2026-09-30, 463 securities); 33.4% of it ($10.64T) matures within 12 months of the book's date (2026-09-30 to 2027-09-30). That block carries a weighted coupon of 3.44%; refinancing it at today's curve (2026-10-16) means 4.20%, which adds +$80.8B a year of interest on the coupon run-rate basis, from $366.2B to $447B. Scenario, not a forecast. Total public debt is $40.39T (Debt to the Penny, 2026-10-15).
For scale, the Treasury's reported interest expense on all debt was $1,360B over the trailing twelve months (October 2025 to September 2026), the same figure the fiscal page uses. That is Treasury's reported interest expense, an accrual measure (interest as it is earned, including amortized discount and TIPS inflation compensation) across marketable and non-marketable debt; the run rates on this page are coupon × outstanding on the marketable book. The two are never mixed.
| Fiscal year | Maturing | Bills | Notes | Bonds | TIPS | FRNs |
|---|---|---|---|---|---|---|
| FY2026 | $0B | $0B | $0B | $0B | $0B | $0B |
| FY2027 | $10,640B | $7,118B | $2,917B | $30B | $223B | $353B |
| FY2028 | $4,002B | $0B | $3,364B | $34B | $249B | $355B |
| FY2029 | $2,824B | $0B | $2,537B | $34B | $253B | $0B |
| FY2030 | $1,984B | $0B | $1,756B | $17B | $211B | $0B |
| FY2031 | $2,254B | $0B | $2,011B | $16B | $226B | $0B |
| FY2032 | $1,225B | $0B | $1,101B | $0B | $124B | $0B |
| FY2033 | $1,151B | $0B | $1,045B | $0B | $107B | $0B |
| FY2034 | $610B | $0B | $497B | $0B | $113B | $0B |
| FY2035 | $677B | $0B | $553B | $0B | $124B | $0B |
| FY2036+ | $6,465B | $0B | $502B | $5,421B | $542B | $0B |
| Bucket | Securities | Outstanding | Share | Weighted coupon | Refi yield (curve) | Current run rate | Refi run rate | Added annual interest |
|---|---|---|---|---|---|---|---|---|
| 0-12m | 112 | $10,640B | 33.4% | 3.44% | 4.20% | $366.2B | $447B | +$80.8B |
| 12-24m | 60 | $3,804B | 12.0% | 3.10% | 4.46% | $117.8B | $169.8B | +$52B |
| 24-36m | 50 | $2,914B | 9.2% | 3.24% | 4.58% | $94.3B | $133.5B | +$39.2B |
| 36-48m | 32 | $1,981B | 6.2% | 3.01% | 4.59% | $59.6B | $90.9B | +$31.3B |
| 48-60m | 35 | $2,364B | 7.4% | 3.06% | 4.65% | $72.4B | $109.9B | +$37.4B |
| 60m+ | 174 | $10,128B | 31.8% | 3.33% | 4.98% | $337.7B | $504B | +$166.3B |
| All marketable | 463 | $31,831B | 100.0% | 3.29% | 4.57% | $1,048B | $1,455.1B | +$407.1B |
coupon × outstanding, an accrual run rate on the marketable book; refinancing yields read off the par curve (real curve for TIPS) at each security's remaining term; the whole book at today's curve is a stress case, not a forecast. TIPS rows carry real coupons and real refinancing yields; inflation compensation is excluded, so they are not directly comparable to the nominal rows. FRN coupons = 3-month bill yield (4.26%, Treasury par curve) plus each note's auction spread.
| Horizon | Outstanding | Share | Weighted coupon | Refi yield | Added annual interest at today's curve |
|---|---|---|---|---|---|
| within 12 months | $10.64T | 33.4% | 3.44% | 4.20% | +$80.8B |
| within 24 months | $14.44T | 45.4% | 3.35% | 4.27% | +$132.8B |
| within 36 months | $17.36T | 54.5% | 3.33% | 4.32% | +$172B |
| within 48 months | $19.34T | 60.8% | 3.30% | 4.35% | +$203.3B |
| within 60 months | $21.7T | 68.2% | 3.27% | 4.38% | +$240.7B |
| all marketable debt | $31.83T | 100.0% | 3.29% | 4.57% | +$407.1B |
The page's slider re-prices the wall live: a parallel shift of the curve applied to every security's refinancing yield, with coupons, amounts and maturities unchanged. At today's curve the added annual interest is +$80.8B for the debt maturing within 12 months, +$132.8B within 24 months and +$240.7B within 60 months.
Gross issuance announced $601B across 8 auctions; maturing in the window $1,123B; net −$522B. Announced auctions from the Treasury auctions dataset (offering amounts as announced), against the securities maturing in the same window. The quarterly refunding statement is a press release, not a dataset; this table is the keyless equivalent for the weeks Treasury has announced.
| Tenor | Auctions | Gross issuance | Reopenings |
|---|---|---|---|
| Bill · 4-Week | 1 | $110B | 1 |
| Bill · 8-Week | 1 | $105B | 1 |
| Bill · 13-Week | 1 | $95B | 1 |
| Bill · 6-Week | 1 | $95B | 1 |
| Bill · 26-Week | 1 | $82B | 0 |
| Bill · 17-Week | 1 | $75B | 0 |
| Note · 5-Year | 1 | $26B | 0 |
| Bond · 19-Year 10-Month | 1 | $13B | 1 |
$31.83T at a weighted coupon of 3.29% costs $1,048B a year on the coupon run-rate basis; at today's curve (weighted refinancing yield 4.57%) it would cost $1,455B, +$407.1B more. The book rolls over years, so this is the rate sensitivity in the stock, not a forecast. For comparison, the Treasury's own average rate on total marketable debt was 3.518% (2026-09-30).
Method: every marketable CUSIP is assigned to a bucket by months to maturity from the MSPD record date, 2026-09-30, so the ladder and the book describe the same day. Coupon = the security's interest rate (bills: the discount yield at issue; FRNs: the 3-month bill yield plus the auction spread; TIPS: the real coupon). Refinancing yield = the par curve (real curve for TIPS) interpolated at the security's remaining term. Run rates = coupon × outstanding, summed; added = refinanced run rate minus current. Refreshed daily at 07:50 ET; the MSPD table changes monthly. Downloads: the ladder (CSV) · every CUSIP with its bucket (CSV).