Treasury Bond vs Treasury Bill: What It Is and Why It Matters

Definition

Treasury bonds (T-bonds) and Treasury bills (T-bills) are both debt securities issued by the U.S. Department of the Treasury to finance government spending. The fundamental difference between them lies in their maturity periods and how they pay interest: T-bills are short-term securities (one year or less) that are sold at a discount and mature at face value, while T-bonds are long-term investments (20 or 30 years) that pay interest semi-annually.

How It Works

When you purchase a U.S. Treasury security, you are essentially lending money to the federal government. In return for this loan, the government promises to pay you back, with interest. Because they are backed by the full faith and credit of the U.S. government, they are considered one of the safest investments in the world.

Treasury Bills (T-Bills)

T-bills are short-term debt instruments with maturities of one year or less. Common maturity terms are four, eight, 13, 17, 26, and 52 weeks. Instead of paying periodic interest, T-bills are sold at a discount to their face (par) value. Your return is the difference between the purchase price and the face value you receive when the T-bill matures. For example, you might buy a $1,000 T-bill for $980. At the end of its term, you would receive the full $1,000, with the $20 difference being your interest earned.

Treasury Bonds (T-Bonds)

T-bonds are the longest-term Treasury securities, with maturities of 20 or 30 years. Unlike T-bills, T-bonds pay interest every six months at a fixed rate. This provides a steady and predictable stream of income for investors. At the end of the bond's term, you receive the full face value of the bond. T-bonds can be bought and sold on the secondary market before they mature, but their market price can fluctuate with changes in interest rates.

Key Rules and Limits

Here are some of the key rules and limits for Treasury bonds and bills in 2026:

Minimum Purchase: The minimum purchase amount for both Treasury bills and bonds is $100.
Maximum Purchase (Non-Competitive Bid): In a non-competitive bid through TreasuryDirect, the maximum purchase amount is $10 million per auction.
Maximum Purchase (Competitive Bid): For competitive bids, an investor can purchase up to 35% of the total offering amount.
Taxation: The interest income from both T-bills and T-bonds is subject to federal income tax but is exempt from state and local income taxes. This can be a significant advantage for investors in high-tax states.
2026 Federal Income Tax Brackets: The interest you earn will be taxed at your ordinary income tax rate. For 2026, the federal income tax brackets are:
- 10% for incomes up to $12,400 for single filers ($24,800 for married couples filing jointly)
- 12% for incomes over $12,400 ($24,800 for married couples filing jointly)
- 22% for incomes over $50,400 ($100,800 for married couples filing jointly)
- 24% for incomes over $105,700 ($211,400 for married couples filing jointly)
- 32% for incomes over $201,775 ($403,550 for married couples filing jointly)
- 35% for incomes over $256,225 ($512,450 for married couples filing jointly)
- 37% for incomes over $640,600 ($768,700 for married couples filing jointly)

Example

Let's consider two investors, Sarah and Tom, who both have $10,000 to invest in 2026.

Sarah chooses a 52-week Treasury Bill:

She purchases a $10,000 face value T-bill at a discount. Based on a forecasted 2026 yield of around 3.12% for short-term Treasuries, she might pay approximately $9,697.
At the end of 52 weeks, the T-bill matures, and she receives the full $10,000 face value.
Her interest income is $303 ($10,000 - $9,697).
This $303 is subject to federal income tax. If Sarah is in the 22% tax bracket, her federal tax would be $66.66. She would pay no state or local income tax on this earning.

Tom invests in a 20-year Treasury Bond:

He purchases a $10,000 face value T-bond with a forecasted 2026 interest rate of approximately 4.83%.
He will receive semi-annual interest payments. The annual interest is $483 ($10,000 * 4.83%), so he receives $241.50 every six months.
Each year, the $483 in interest income is subject to federal income tax. If Tom is in the 24% tax bracket, his annual federal tax on this interest would be $115.92. He would not owe any state or local taxes on this income.
After 20 years, Tom will receive his original $10,000 principal back.

Pros and Cons

Treasury Bills

Pros:

Extremely Safe: Backed by the full faith and credit of the U.S. government, T-bills have virtually no default risk.
Highly Liquid: Their short-term nature and active secondary market make them easy to convert to cash.
Tax Advantages: Interest is exempt from state and local taxes.
Protection in Volatile Markets: T-bills can be a safe haven for capital during times of economic uncertainty.

Cons:

Lower Returns: T-bills typically offer lower yields compared to longer-term bonds and other investments.
Reinvestment Risk: When a T-bill matures, you face the risk that interest rates on new T-bills may be lower.
Inflation Risk: The return on T-bills may not keep pace with inflation, potentially leading to a loss of purchasing power.

Treasury Bonds

Pros:

High Safety: Like T-bills, T-bonds are considered one of the safest investments available.
Predictable Income: The fixed semi-annual interest payments provide a reliable income stream.
Higher Yields than T-bills: Generally, T-bonds offer higher interest rates than T-bills to compensate for the longer maturity.
Tax Advantages: Interest income is exempt from state and local taxes.

Cons:

Interest Rate Risk: If interest rates rise, the market value of existing, lower-yielding T-bonds will fall. If you need to sell your bond before maturity, you could lose principal.
Inflation Risk: Over a long 20 or 30-year term, the fixed interest payments may not keep up with the rising cost of living.
Less Liquidity: While they can be sold on the secondary market, the long maturity makes them less liquid than short-term T-bills.

Common Mistakes to Avoid

Ignoring Interest Rate Risk with T-Bonds: Many investors don't fully appreciate that the market value of their T-bonds can decrease if interest rates go up. If you might need your principal back before the bond matures, this is a significant risk.
Overlooking Reinvestment Risk with T-Bills: It's easy to focus on the current attractive yield of a T-bill, but forget that you'll have to reinvest the proceeds at potentially lower rates when it matures.
Not Considering Inflation: While Treasury securities are safe from default, they are not immune to the eroding effects of inflation. It's crucial to consider the real, after-inflation return on your investment.
Forgetting About Federal Taxes: The state and local tax exemption is a great benefit, but remember that you will still owe federal income tax on the interest you earn.
Buying Through a Broker Without Checking Fees: While convenient, some brokers may charge commissions for buying Treasury securities. You can purchase them for free directly from the government through the TreasuryDirect website.

Frequently Asked Questions

Q: How do I buy Treasury bonds and bills?

A: You can buy Treasury securities in a few ways: directly from the U.S. Treasury through their website, TreasuryDirect, which is commission-free; through a bank or broker; or through a mutual fund or exchange-traded fund (ETF) that invests in Treasury securities.

Q: Can I sell a Treasury bond or bill before it matures?

A: Yes, both T-bonds and T-bills can be sold on the secondary market before their maturity date. However, the price you receive will depend on current interest rates. If interest rates have risen since you purchased your security, you may have to sell it at a loss.

Q: Are Treasury bonds and bills a good investment for retirement?

A: They can be, depending on your financial goals and risk tolerance. Their safety and predictable income can be attractive for retirees. However, the lower returns may not be sufficient for everyone's retirement needs, and inflation risk is a key consideration for long-term T-bonds.

This article reflects 2026 rules and limits. Tax laws and financial regulations change — consult a qualified financial advisor or visit IRS.gov for the latest information.