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How do i bonds work

What Are I Bonds?

Series I savings bonds are U.S. government-backed savings bonds sold through TreasuryDirect, the official platform for electronically buying and redeeming U.S. savings bonds.

I bonds are designed to help protect savings from inflation. They earn a composite interest rate made up of a fixed component and an inflation-adjusted component.

How I Bond Interest Rates Work

The interest rate on an I bond is made up of two components: a fixed rate and an inflation-adjusted rate. For I bonds issued between May 1, 2026 and October 31, 2026, the composite rate is 4.26%, which includes a fixed rate of 0.90%.

Because part of the rate adjusts with inflation, the total rate can change over time, meaning the earnings on an I bond are not static across its full life.

How I Bonds Compare to EE Bonds

Series EE savings bonds are also a low-risk savings option that earn interest regularly for 30 years (or until you cash them if you do that before 30 years). Unlike I bonds, EE bonds carry a fixed rate — currently 2.40% for bonds issued between May 1, 2026 and October 31, 2026.

A key feature of EE bonds is a government guarantee that the bond will double in value in 20 years, even if the accumulated interest alone would not reach that amount. I bonds do not carry this same doubling guarantee.

Estimating Your Bond's Value

Because savings bond values depend on issue date, bond series, and changing interest rates, it can be difficult to calculate earnings manually. TreasuryDirect offers a Savings Bond Value Calculator, and you can also use our free savings bond calculator at / to quickly estimate what your bond is worth today.

Whether you hold I bonds or EE bonds, knowing the current value helps you make informed decisions about when to hold or redeem your bonds.

Key takeaways

  • I bonds earn a composite interest rate made up of a fixed component and an inflation-adjusted component, currently totaling 4.26% for bonds issued May 1–October 31, 2026.
  • EE bonds guarantee the bond will double in value in 20 years, while I bonds are structured to help savings keep pace with inflation.
  • Both I bonds and EE bonds can only be purchased and redeemed electronically through TreasuryDirect, the official U.S. government platform.
  • Interest rates on both bond series are updated periodically, so the rate applied to your bond depends on when it was issued.

Related tools

Estimate materials with our free savings bond calculator on Savings Bond Calculator.

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