The annual interest rate on a United States treasury bond fluctuates and depends on the time length of the bond. As of October 2015, treasury bonds lasting less than one year have rates of zero or slightly above zero, whereas 30-year bonds have rates fluctuating between 2.80 and 3.00 percent.
The U.S. Department of Treasury website provides a listing of interest rates on treasury bonds for various bond lengths, as well as the daily historical rates for each bond. Rates are available for bonds lasting one, three, and six months and one, two, three, five, seven, 10, 20 and 30-year bonds. The annual interest rate increases as the bond length increases. For example, a one-year bond has an interest rate of under 0.30 percent, whereas a five-year bond has annual rates around 1.30 to 1.40 percent.