One of the quieter findings in the GAO’s March 2026 federal debt management report (GAO-26-107529) is the degree to which the U.S. government has increased its reliance on short-term borrowing — and what that implies for fiscal exposure to interest rate movements.

In fiscal year 2014, Treasury bills accounted for 13 percent of marketable debt held by the public. By fiscal year 2025 that share had risen to 22 percent, against a long-term historical average of 20 percent. Notes declined as a share but still constitute over half of all outstanding debt. Bonds increased from 12 to 17 percent, partly due to the reintroduction of the 20-year bond in 2020.