Treasury bonds, notes, and bills are all fixed-income securities issued by the U.S. Treasury. The primary difference between them is their maturity dates and the frequency of interest payments. Treasury bills have the shortest maturities, ranging from four weeks to one year, and they only pay interest when they mature. Treasury notes are issued with maturities ranging from two to 10 years, and pay interest every six months. And Treasury bonds mature in either 20 or 30 years, also paying interest every six months.