Learn How I Bonds Work

Exterior of the United States Treasury Department
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For bond investors, the loss of purchasing power due to inflation is a major fear. For example, let's say you earn the same amount of interest income each year, but the cost of food, shelter, and transportation continues to climb. That means your standard of living will shrink with each passing day until you find yourself unable to afford the things you need. And that's not to mention being able to afford the things you want.

That's why the Series I bonds were introduced as the newest member of the U.S. savings bonds family. Each Series I bond pays interest based on two components: a fixed rate of return plus a semi-annual variable rate that changes with fluctuations in inflation as measured by the consumer price index, or CPI. That may sound complicated, but it can be quite simple.

Learn how you can take advantage of it as a new bond investor.

Key Takeaways

  • Series I bonds are inflation-beating savings bonds issued by the U.S. government.
  • You pay the face value of the bond and receive interest and an inflation adjustment.
  • Savings bonds are not transferrable, so they must be purchased from the U.S. Treasury or certain banks and payroll programs.

How Series I Savings Bonds Work

When you purchase a Series I savings bond, you pay the full face value of the bond itself. In other words, if you acquire a $5,000 face-value I bond, you will pay $5,000. This is true regardless of whether you purchase paper I bond certificates or electronically registered I bonds through the U.S. Treasury Department website, TreasuryDirect.

Paper bonds are sold in multiples of $50, $100, $200, $500, or $1,000. Electronic bonds can be purchased in any amount from $25 to $10,000, down to the penny.


Series I bonds earn interest starting on the first day of each month. That interest is compounded semi-annually based upon the issue date of the specific I bond.

The I bond issue date is the month and year in which the financial institution through which you purchased your I bond receives the full issue price of the bond. This is important because it means that your I bond is really a type of zero-coupon bond. Unlike a traditional corporate bond or municipal bond, you won't receive checks in the mail for the interest you earned. Instead, the value of your I bond will increase regularly. That interest will be added to the principal value.

Only when you cash the bond in (known as "redeeming" the bond) will you get your money back—plus all of the interest you've made over the years. Interest will accrue on your bond until you redeem it or 30 years have passed since the date of issue, whichever comes first.


Not everyone is eligible to own I bonds. You must be a U.S. citizen, a U.S. resident, or a civilian employee of the U.S.

The Risks of Investing Money in I Bonds

Remarkably, I bonds are one of the only investments in the world that the U.S. government guarantees. If inflation picks up, you will earn more interest through the inflation adjustment. If the economy enters deflation, the I bonds have a guarantee that they will never go below 0% interest per year. This means your purchasing power would continue to increase, even if you weren't earning any interest on your money.

How Long You Have to Hold I Bonds

Series I savings bonds are not intended to be traded, but rather held as long-term investments. You cannot cash them in for at least 12 months after buying each I bond. If you redeem the bonds before the five-year anniversary of the purchase date, you will pay a penalty of the last three months' interest.

How I Bonds Are Taxed

I bonds are exempt from state and local taxes. They are, however, subject to federal taxes, but you as an investor have the option to pay taxes on a cash basis or an accrual basis.

Under the cash method, you wouldn't pay taxes until you redeem your bond—because even though you had earned the interest income, you hadn't actually seen any of that money. Under the accrual method, you would pay taxes each year on the income you earned that was added back to the value of your I bond.


Many investors prefer the cash method of taxation so they don't have to pay taxes out of their own pocket each year. Instead, they use the bond proceeds when they sell the bond to cover any obligations to the government.

What Happens if You Lose I Bonds

Like all savings bonds, I bonds are known as "registered" securities. This means that even if you lose your I bond certificate (assuming you bought paper certificates instead of using the online program), there is no need to panic. That's because you are registered as the owner. Simply contact the Treasury Department, fill out the paperwork they require, and you will be issued a replacement I bond.

This also means you need to be careful: These bonds are non-transferable. You can never purchase an I bond from another investor because the Treasury will still recognize the original owner as the rightful one—not you. You can only buy I Bonds from the U.S. Treasury, some banks, and certain payroll purchase plans.

If you purchase I bonds from another investor, they still legally own the right to those bonds, and you will have lost your money.

Alternatives to the I Bond

A lot of professional investors, private investors, and wealthy business owners prefer to own TIPs, or Treasury Inflation-Protected Securities, instead of I bonds. That's because TIPs have much higher annual purchase limits each year. While you can buy millions in TIPs, the most you can buy in I bonds is $10,000 per year.

Often, I bonds aren't right for wealthy individuals or people who manage a large amount of money. That's because the purchase limits are too low to be of much use.

Frequently Asked Questions (FAQs)

How can I purchase I bonds?

You can purchase I bonds in electronic form online or in paper form when you file your federal income tax form.

Can I buy I bonds for other people?

Yes. If you're buying them online, you can buy them for anyone with a Treasury Direct account, including minors. If you buy paper bonds, you can order them in the name of the recipient and give that person the paper bond.

What's the minimum purchase for an I bond?

You can buy an electronic bond for $25 or a paper bond for $50.

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The Balance uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. U.S. Department of the Treasury. "Series I Savings Bonds."

  2. U.S. Department of the Treasury. "Buying I Bonds."

  3. TreasuryDirect.gov. "Tax Considerations for I Bonds."

  4. U.S. Department of the Treasury. "Series I Savings Bonds FAQs."

  5. U.S. Department of the Treasury. "Treasury Inflation-Protected Securities (TIPS)."

  6. Treasury Direct. "Buying Series I Savings Bonds."

  7. Treasury Direct. "Buying Series I Bonds."

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