What are Treasury bills in plain terms?
Treasury bills, or T-bills, are short-term debt securities issued by the U.S. Department of the Treasury. The government borrows money for a fixed term of 4 to 52 weeks and repays the full face value at maturity.
T-bills don’t pay a stated interest rate. Instead, they sell at a discount to face value, and the difference between the purchase price and the face value is the return.
For example, a $10,000 T-bill might sell for $9,980. Four weeks later, the holder receives $10,000, a $20 gain on a $9,980 investment.
So what: the discount structure means the “interest” is built into the purchase price, not paid out separately.
Why do Treasury bills exist?
The federal government collects tax revenue unevenly through the year but spends money continuously. T-bills let the Treasury borrow short-term cash to cover that timing gap without locking in long-term interest rates.
Auctions happen on a set schedule: 4-week and 8-week bills weekly, longer terms roughly monthly. Bidders submit orders through TreasuryDirect, banks, or brokers, and the Treasury accepts bids until it raises the amount it needs.
So what: T-bill issuance is a cash-management tool for the government, not a product designed around investor demand.
How Treasury bills work in practice
An auction is announced, bids are accepted, results are posted, and funds settle a few days later, typically within the same week. Buyers can purchase directly through TreasuryDirect.gov with no fee and a $100 minimum, through a brokerage account (which may charge $1 to $5 per transaction and require a higher minimum), or indirectly through a money market fund that holds a portfolio of T-bills.
A money market fund charges an ongoing management fee, commonly in the range of 0.05% to 0.30% annually, in exchange for daily liquidity and diversification across many bills.
Because auctions run on a schedule, a buyer cannot purchase a new T-bill on demand between auction dates. A bill already issued can still be bought or sold on the secondary market before it matures.
So what: the purchase method determines the fee, the minimum amount, and how quickly the money can be accessed again.
What it is not (boundaries and confusions)
A T-bill is not a savings account. A bank deposit is insured by the FDIC up to $250,000 per depositor, per bank, while a T-bill carries no dollar cap because it is backed by the federal government directly.
A T-bill is also not the same as a Treasury note or Treasury bond. Notes mature in 2 to 10 years and bonds in 20 to 30 years, and both pay interest twice a year instead of selling at a discount.
A T-bill differs from a certificate of deposit too. A CD is a bank product with an early-withdrawal penalty, while a T-bill held to maturity has no penalty, and one sold early goes through the secondary market at whatever price it commands that day.
So what: T-bills sit in a specific slot between checking-account cash and multi-year bonds, distinct from bank products with similar-sounding names.
What it changes for users and institutions
Interest earned on T-bills is subject to federal income tax but exempt from state and local income tax. A bank savings account’s interest, by comparison, is taxed at both the federal and state level in states that tax income.
Institutions use T-bills as a benchmark for short-term interest rates and as high-quality collateral in lending markets. Banks also hold them to satisfy liquidity requirements under banking regulations such as Basel III’s high-quality liquid asset rules.
Individual buyers sometimes stagger purchases across different maturities, known as laddering, so a portion of the money becomes available every few weeks instead of all at once.
So what: the state tax exemption and the staggered-maturity structure are the two features that distinguish T-bills from an ordinary deposit account.
Tradeoffs, risks, or limitations
Money placed in a T-bill is unavailable until maturity unless it is sold on the secondary market, and a sale before maturity can produce a gain or a loss depending on where rates have moved since purchase.
T-bill yields are fixed at purchase and don’t adjust afterward. If inflation runs higher than the yield during the holding period, the real return can turn negative.
Auctions follow a fixed calendar, so a buyer who needs a bill outside that window has to either wait for the next auction or buy an already-issued bill on the secondary market, often at a less predictable price.
When a bill matures, reinvesting the proceeds in a new bill happens at whatever rate the market offers at that time, which may be lower or higher than the rate that just matured.
So what: T-bills carry very low credit risk but real liquidity, inflation, and reinvestment tradeoffs that a checking or savings account structure avoids.
Common questions
Can I lose money on a Treasury bill?
Holding a T-bill to maturity returns the full face value, so there is no loss from the issuer. A loss is only possible if the bill is sold on the secondary market before maturity at a price below what was paid.
Do Treasury bills pay interest like a savings account?
No. A T-bill is sold at a discount to face value and matures at full face value, so the return comes from that price difference rather than a periodic interest payment.
How is Treasury bill income taxed?
Interest is subject to federal income tax as ordinary income but is exempt from state and local income tax, unlike interest on a typical bank account.
What is the difference between a T-bill and a Treasury note?
T-bills mature in 4 to 52 weeks and are sold at a discount. Treasury notes mature in 2 to 10 years and pay interest twice a year instead.
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