Collection: US Treasury Bills (T-Bills)

Treasury bills (T-bills) are zero-coupon bonds that mature in one year or less. They are bought at a discount of the par value and, instead of paying a coupon interest, are eventually redeemed at that par value to create a positive yield to maturity.

Regular T-bills are commonly issued with maturity dates of 4, 8, 13, 17, 26 and 52 weeks, each of these approximating a different number of months. Treasury bills are sold by single-price auctions held weekly. Offering amounts for 13-week and 26-week bills are announced each Thursday for auction on the following Monday and settlement, or issuance, on Thursday. Offering amounts for 4-week and 8-week bills are announced on Monday for auction the next day, Tuesday, and issuance on Thursday. Offering amounts for 52-week bills are announced every fourth Thursday for auction the next Tuesday, and issuance on the following Thursday. The minimum purchase is $100; it had been $1,000 prior to April 2008. Mature T-bills are also redeemed on each Thursday. Banks and financial institutions, especially primary dealers, are the largest purchasers of T-bills.

Like other securities, individual issues of T-bills are identified with a unique CUSIP number. The 13-week bill issued three months after a 26-week bill is considered a re-opening of the 26-week bill and is given the same CUSIP number. The 4-week bill issued two months after that and maturing on the same day is also considered a re-opening of the 26-week bill and shares the same CUSIP number. For example, the 26-week bill issued on March 22, 2007, and maturing on September 20, 2007, has the same CUSIP number (912795A27) as the 13-week bill issued on June 21, 2007, and maturing on September 20, 2007, and as the 4-week bill issued on August 23, 2007, that matures on September 20, 2007.

During periods when Treasury cash balances are particularly low, the Treasury may sell cash management bills (CMBs). These are sold through a discount auction process like regular bills, but are irregular in the amount offered, the timing, and the maturity term. CMBs are referred to as "on-cycle" when they mature on the same day as a regular bill issue, and "off-cycle" otherwise. Before the introduction of the four-week bill in 2001, the Treasury sold CMBs routinely to ensure short-term cash availability. Since then CMB auctions have been infrequent except when the Treasury has extraordinary cash needs.

Treasury bills are quoted for purchase and sale in the secondary market on an annualized discount percentage, or basis.