One in three dollars of the Treasury's $31.45 trillion in marketable debt comes due within a year — we read all 462 securities, and the share is rising while the average maturity shortens

The number that governs the government's exposure to interest rates is not the rate it pays. It is how fast the debt comes back to be refinanced — because as maturing debt is replaced by new borrowing, the government's cost migrates toward whatever the market charges then, not the rate the retiring debt carried when it was sold. So we read the whole stock. Every one of the 462 dated marketable Treasury securities outstanding on July 31, 2026 — every bill, note, bond, inflation-protected security and floating-rate note in the Monthly Statement of the Public Debt that carries a maturity date — sorted by the day it comes due. (Treasury reports one more marketable line, an undated $3.591 billion Federal Financing Bank balance with no maturity date to sort by; it is noted but not placed on the ladder.) The per-security amounts sum to $31.45 trillion and reconcile to the Treasury's own published subtotals (Total Unmatured Treasury Notes $16.17T, Bills $6.99T, Bonds $5.49T, TIPS $2.15T, FRNs $0.65T). One dollar in three matures within the year. $10.48 trillion — 33.3% of the marketable total — comes due on or before July 31, 2027. Push the window to two years and it is 45.7%; to three years, 54.7% — a majority of all tradable federal debt turns over inside three years. The weighted-average maturity of the stock is 5.84 years. The near-term wall is not just Treasury bills. Bills — which by definition mature in a year or less — account for $6.99 trillion of it. The other $3.49 trillion is notes, bonds, TIPS and floating-rate notes that were issued years ago and now reach maturity within twelve months.

Read the same population a year earlier and the direction is clear. On July 31, 2025 the marketable stock was $28.97 trillion across 457 securities, with $9.25 trillion — 31.9% — maturing within a year and a weighted-average maturity of 5.99 years. Over the twelve months the total grew $2.49 trillion (+8.6%), the amount due within a year grew faster, up $1.23 trillion (+13.3%), the one-year share rose 1.4 points to 33.3%, and the average maturity shortened by about eight weeks. The debt got bigger and, at the margin, shorter. That is what raises the stakes of the rate the Treasury pays. As of the same July 31 statement, the average rate across all marketable debt was 3.443%, and the total interest-bearing average was 3.447%. The faster a third of the stock rolls over, the faster the whole book's average cost migrates toward current market rates — to the extent maturing debt is replaced by new issuance — rather than the sub-1% coupons of 2020–21. And the curve inside the wall is inverted: bills carry an average rate of 3.758%, above the longer-dated notes (3.309%) and bonds (3.442%) — and the floating-rate notes that reset off the short end cost more still, 3.948%. The short end of the government's book is, per dollar, its most expensive today. None of this is a judgment about whether the borrowing is prudent — only about what the full record shows: a large, growing share of the debt reprices to the rates prevailing when it is refinanced, on a short clock, and the clock is running slightly faster than it was a year ago.

A short maturity profile is not a crisis, and this is not one. Rolling over a third of the marketable stock a year is routine; the Treasury auctions it continuously, and a heavy bill share reflects a deliberate debt-management choice weighed against rollover risk, not an accident. Near-term maturities measure refinancing and repricing exposure, not default risk. Two measurement caveats bound the figure. Bills are reported at maturity (face) value, which modestly overstates the one-year bucket against their discounted issue price; and this is the marketable stock only — it excludes roughly $7.7 trillion of nonmarketable Government Account Series — the intragovernmental holdings of federal trust funds — which do not trade or reprice in the market. Repricing also cuts both ways: some of the coupon debt maturing this year was issued in 2023–24 at rates near or above today's, so rolling it is closer to neutral than the headline "low-rate debt repricing up" suggests — the aggregate says the stock tracks market rates faster, not that every rollover costs more ^sspeculative.