Debt obligations of the U.S. government. Treasuries are among the safest investments. since the full faith and credit of the government secure them. The interest of Treasuries is exempt from state and local taxes but is subject to federal income tax. There are three types of treasuries: Treasury Bills. with maturities of one year or less; Treasury Notes. with maturities ranging from one to 10 years; and Treasury Bonds. long-term instruments with maturities of 10 years or more.