Treasury bills (T-bills), which are guaranteed by the full faith and credit of the U.S. Government, are issued at a discount; they pay no interest, but receive full face value if held until maturity. Exempt from state and local taxes, T-bills are issued in minimum denominations of $10,000, and in multiples of $1,000 thereafter. With the shortest maturities -- three and six months, and one year at issue -- T-bills are considered the least volatile of all Treasuries.