Short-term debt obligations issued by the U.S. Treasury that matures in 3 to 12 months. Common maturities for T-bills include 13-, 26-, and 52-weeks. Typically, they are sold weekly to institutions, but individuals also can buy T-bills through the Bureau of Public Debt. Because they are obligations of the U.S. government, T-bills are considered to be risk free. The minimum purchase amount is $1,000, with bids made in multiples of $1,000. Generally, noncompetitive bids from one person may not exceed $1 million for Treasury bills or $5 million for a Treasury note or bond offering.