The average rate the Treasury actually pays on its outstanding debt, by instrument. It lags market yields by construction — bills reprice fully within a year, while notes and bonds only reset at refinancing — so the gap between this average and current market yields measures how much interest-cost repricing is still in the pipeline.
This graph shows the average interest rate of outstanding treasury securities. Many other securities of marginal amount are excluded.
Why it matters: This is the core variable of the interest-cost snowball: interest outlays ≈ debt stock × the average rate on this page. When hikes began in 2022, the bill rate jumped to the policy rate almost immediately, while the average coupon on notes and bonds stayed anchored at 2010s levels — since then, every maturity rolled has swapped a 1–2% legacy coupon for one above 4%, which is why the average keeps grinding higher even after the Fed stops hiking. The same logic runs in reverse: how quickly cuts relieve the fiscal bill depends on the debt's weighted average maturity — the shorter the WAM, the faster the pass-through. Cross-checking this page against interest outlays in the MTS verifies the whole chain.