$31.82T of marketable Treasury debt is outstanding (MSPD Table 3, 2026-08-31, 463 securities); 34.0% of it ($10.83T) matures within 12 months of 2026-09-15. That block carries a weighted coupon of 3.40%; refinancing it at today's curve (2026-09-10) means 3.96%, which adds +$60.8B a year of interest on the coupon run-rate basis, from $368.1B to $428.9B. Scenario, not a forecast. Total public debt is $40.05T (Debt to the Penny, 2026-09-11).
For scale, the Treasury's reported interest expense on all debt was $1,359B over the trailing twelve months (September 2025 to August 2026), the same figure the fiscal page uses. That is a reported cash measure 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 | $2,708B | $2,491B | $217B | $0B | $0B | $0B |
| FY2027 | $8,292B | $4,757B | $2,930B | $30B | $223B | $353B |
| FY2028 | $3,906B | $0B | $3,296B | $34B | $249B | $327B |
| FY2029 | $2,766B | $0B | $2,479B | $34B | $253B | $0B |
| FY2030 | $1,984B | $0B | $1,756B | $17B | $211B | $0B |
| FY2031 | $2,173B | $0B | $1,930B | $16B | $226B | $0B |
| FY2032 | $1,225B | $0B | $1,101B | $0B | $125B | $0B |
| FY2033 | $1,101B | $0B | $994B | $0B | $107B | $0B |
| FY2034 | $612B | $0B | $499B | $0B | $113B | $0B |
| FY2035 | $677B | $0B | $553B | $0B | $125B | $0B |
| FY2036+ | $6,379B | $0B | $463B | $5,395B | $521B | $0B |
| Bucket | Securities | Outstanding | Share | Weighted coupon | Refi yield (curve) | Current run rate | Refi run rate | Added annual interest |
|---|---|---|---|---|---|---|---|---|
| 0-12m | 113 | $10,827B | 34.0% | 3.40% | 3.96% | $368.1B | $428.9B | +$60.8B |
| 12-24m | 62 | $3,903B | 12.3% | 3.04% | 4.29% | $118.8B | $167.5B | +$48.8B |
| 24-36m | 49 | $2,835B | 8.9% | 3.17% | 4.40% | $90B | $124.7B | +$34.7B |
| 36-48m | 32 | $1,981B | 6.2% | 3.01% | 4.42% | $59.6B | $87.5B | +$28B |
| 48-60m | 33 | $2,238B | 7.0% | 2.98% | 4.48% | $66.8B | $100.4B | +$33.6B |
| 60m+ | 174 | $10,040B | 31.5% | 3.32% | 4.87% | $333B | $488.7B | +$155.8B |
| All marketable | 463 | $31,824B | 100.0% | 3.26% | 4.39% | $1,036.2B | $1,397.7B | +$361.5B |
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%, DGS3MO) plus each note's auction spread.
| Horizon | Outstanding | Share | Weighted coupon | Refi yield | Added annual interest at today's curve |
|---|---|---|---|---|---|
| within 12 months | $10.77T | 33.8% | 3.40% | 3.96% | +$60.2B |
| within 24 months | $14.73T | 46.3% | 3.31% | 4.05% | +$109.5B |
| within 36 months | $17.57T | 55.2% | 3.28% | 4.11% | +$144.2B |
| within 48 months | $19.55T | 61.4% | 3.26% | 4.14% | +$172.2B |
| within 60 months | $21.78T | 68.5% | 3.23% | 4.17% | +$205.8B |
| all marketable debt | $31.82T | 100.0% | 3.26% | 4.39% | +$361.5B |
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 +$60.2B for the debt maturing within 12 months, +$109.5B within 24 months and +$205.8B within 60 months.
Gross issuance announced $644B across 11 auctions; maturing in the window $1,544B; net −$899.7B. 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 · 13-Week | 1 | $92B | 1 |
| Bill · 4-Week | 1 | $90B | 1 |
| Bill · 8-Week | 1 | $85B | 1 |
| Bill · 26-Week | 1 | $79B | 1 |
| Bill · 6-Week | 1 | $75B | 1 |
| Bill · 17-Week | 1 | $72B | 0 |
| Note · 3-Year | 1 | $58B | 0 |
| Note · 9-Year 11-Month | 1 | $39B | 1 |
| Bond · 29-Year 11-Month | 1 | $22B | 1 |
| Note · 9-Year 10-Month | 1 | $19B | 1 |
| Bond · 19-Year 11-Month | 1 | $13B | 1 |
$31.82T at a weighted coupon of 3.26% costs $1,036B a year on the coupon run-rate basis; at today's curve (weighted refinancing yield 4.39%) it would cost $1,398B, +$361.5B 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 3.475% (2026-08-31).
Method: every marketable CUSIP is assigned to a bucket by months to maturity from 2026-09-15. 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).