Treasury yields surged to their highest levels in years before the Memorial Day weekend, with 30-year bonds touching 5.2% and the benchmark 10-year note reaching 4.7%. Those moves matter because Washington is already carrying $39 trillion in government debt and is set to borrow almost $10 trillion over the next 12 months.
The timing is what has caught budget watchers' attention. Federal interest expense is already running at nearly $1 trillion a year, more than Medicare spending and equal to two-thirds of Social Security outlays. When borrowing costs jump on that scale, the bill is no longer theoretical. It shows up in the Treasury's financing math almost immediately, and it does so while the government still has to roll over existing obligations and fund fresh deficits.
The Congressional Budget Office's Budget and Economic Outlook: 2026 to 2036, released in February, assumes those rates ease back from the recent spike. It projects 30-year yields averaging about 4.65% through fiscal 2036 and 10-year yields averaging about 4.15%. That is only modestly below the recent peaks, but over time even a small gap can mean a far larger interest tab for taxpayers than today's baseline suggests.
A report from the Committee for a Responsible Federal Budget took that point further. It said if recent peak yields persisted, interest expense would rise to $2.5 trillion by 2036, or 2.5 times today's cost. Under that path, interest would absorb 30% of all revenues, become the second-largest budget category and run one-third above Medicare. Per household, the burden would climb from $7,900 last year to $17,000 a decade from now.
The strain is amplified by what the government has to finance right now. About $7.5 trillion of the next 12 months' borrowing will go to replacing Treasuries coming due, while roughly $2 trillion will cover the gap between revenues and spending. Treasury bills that paid around 0.2% in 2021 and early 2022 now cost 3.7%, and notes maturing from five to 30 years make up more than half of all federal debt outstanding. The average rate on those Treasury notes stands at 3.23%, leaving little cushion if market rates stay elevated.
That is the real pressure point. Low borrowing costs during and after the COVID crisis helped Washington build up debt, but the current rate environment shows how quickly the interest burden can compound once the market demands more. The open question now is not whether higher yields can hurt the budget — they already are — but how long the Treasury can live with rates near these levels before the financing picture forces a harder response.
