The meaning and definition of Treasury Security -
Debt obligations of the U.S. government. Treasury securities are considered to be among the safest investments because they are backed by the full faith and credit of the U.S. government. The interest on Treasury securities 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.