The Congressional Budget Office (CBO) expects total federal borrowing from the public to reach $28.2 trillion in 2024 — the highest amount ever recorded. That figure represents the net amount that the United States Treasury has borrowed from creditors by issuing securities that raise cash to support government activities. Debt held by the public does not include intragovernmental debt, which, in simple terms, is debt that the government owes itself. As the United States continues to borrow a significant amount of money each year, let’s take a closer look at a few key characteristics of Treasury borrowing that can affect its budgetary cost, including the different types of Treasury securities issued to the public as well as trends in interest rates and maturity terms.

Types of Treasury Securities

The U.S. Treasury offers marketable and nonmarketable securities. Marketable securities are sold at auction in various maturities and traded on secondary markets. Such securities represented 98 percent of all debt held by the public as of June 2024. Nonmarketable securities are issued directly to buyers (rather than auctioned) and are not traded in secondary markets; that type of issuance made up just 2 percent of total debt held by the public at the end of June 2024.

Marketable Treasury securities are issued in various forms:

• Treasury Bills have a maturity of one year or less. Such short-term securities are issued at a discount and the face value is paid upon maturity. Bills represented about 21 percent of all outstanding marketable Treasury debt at the end of June 2024.
• Treasury Notes have maturities ranging from two to 10 years. Notes are coupon securities, which means that the semiannual interest payments are set at the time of issuance and purchasers collect the principal at maturity. Notes are the single largest category of Treasury securities, representing about 52 percent of all marketable debt at the close of June 2024.
• Treasury Bonds have maturities of more than 10 years. Bonds are also coupon securities and represented about 17 percent of all marketable debt at the end of June 2024.
• Treasury Inflation-Protected Securities, or TIPS, have maturities of 5, 10, and 30 years. The principal amount on TIPS are adjusted semiannually to account for inflation; interest is paid every six months on the adjusted principal. TIPS represented roughly 8 percent of all marketable debt at the end of June 2024.
• Floating-Rate Notes (FRNs) have a maturity of two years and a rate of interest that is adjusted each quarter; the rate is based on the prevailing interest rate for 13-week Treasury bills. Introduced in 2014, FRNs represented 2 percent of total marketable debt at the end of June 2024.

While Treasury notes account for the majority of outstanding securities, the share of marketable debt represented by such securities has declined over the years — from 66 percent in 2014 to 52 percent today. That share has declined due to the increased issuance of other securities such as bonds and bills in response to the federal government’s borrowing needs. For example, bills represented 12 percent of total marketable debt at the end of 2014, but borrowing to address the pandemic boosted that share to 24 percent in 2020, reflecting the comparative ease with which the Treasury can raise cash quickly by issuing bills. Today, bills represent 21 percent of marketable debt as pandemic-related borrowing has stopped.