Series I savings bonds are U.S. savings bonds whose interest rate combines a fixed rate with an inflation rate. They can be useful for money that you want protected from inflation over a multi-year period, but they are not a substitute for an immediately accessible emergency fund because new I Bonds cannot generally be redeemed for the first 12 months.
As of September 2026, TreasuryDirect lists a 4.26% composite rate for I Bonds issued from May 1, 2026 through October 31, 2026. That rate includes a 0.90% fixed rate. The fixed rate stays with the bond for its life, while the inflation component resets every six months.
An I Bond has two rate components
TreasuryDirect says the I Bond composite rate combines a fixed rate and a semiannual inflation rate.
The fixed rate is set when the bond is issued and does not change during the bond’s 30-year interest-bearing life. The inflation rate is recalculated every six months based on changes in the non-seasonally adjusted CPI-U.
The current 4.26% rate is not a permanent 30-year rate
The 4.26% composite rate applies for the first six months to I Bonds issued from May through October 2026.
After that, the bond moves to a new composite rate based on its permanent 0.90% fixed rate and the next applicable inflation component.
Treasury announces new I Bond rates every May 1 and November 1
The government resets the fixed rate for newly issued bonds and announces a new inflation rate twice each year.
Existing bonds keep their original fixed component but receive new inflation components on their individual six-month schedules.
Interest accrues monthly and compounds semiannually
TreasuryDirect’s May 2026 rate release says I Bond interest accrues monthly and compounds semiannually.
You do not receive a monthly cash payment. The interest becomes part of the bond’s redemption value.
I Bonds can earn interest for up to 30 years
TreasuryDirect says savings bonds can earn interest until they are redeemed or reach 30 years old.
That makes I Bonds potentially useful for long-term inflation-sensitive savings, although you are free to redeem after the minimum holding period.
You currently can buy up to $10,000 of electronic I Bonds per calendar year
TreasuryDirect says one Social Security Number or eligible entity tax identification number can buy up to $10,000 of electronic I Bonds in a calendar year.
The limit is separate from the $10,000 annual electronic EE Bond limit.
New paper I Bonds are no longer available through federal tax refunds
The old tax-refund option that allowed certain taxpayers to buy paper I Bonds was discontinued. TreasuryDirect now directs new I Bond purchases to electronic bonds.
That means the ordinary current purchase path is the $10,000 electronic annual limit through TreasuryDirect.
Electronic purchases can be as small as $25
TreasuryDirect currently lets investors buy electronic I Bonds from $25 up to the annual limit and specify the purchase amount to the penny.
That makes it possible to build an I Bond position gradually rather than buying the full annual amount at once.
You cannot redeem a new I Bond during the first 12 months
TreasuryDirect currently says I Bonds issued after February 2003 generally cannot be cashed until 12 months after the issue date.
This is the main reason I Bonds should not hold the first layer of an emergency fund.
Redeeming before five years costs the last three months of interest
If you cash an I Bond after the one-year minimum but before it is five years old, Treasury says you forfeit the most recent three months of interest.
For example, if you redeem after 18 months, you receive the first 15 months of interest.
After five years there is no early-redemption interest penalty
Once the bond reaches five years, Treasury’s current rules allow redemption without the three-month interest penalty.
The bond can still continue earning under the I Bond rate formula until year 30 if you do not cash it.
Example: money needed in six months
I Bonds are a poor fit for a tuition bill, home down payment, or tax obligation that must be paid six months from now.
The 12-month lock prevents access even if the money is urgently needed.
Example: second layer of an emergency reserve
A household already has six months of liquid savings in bank accounts and wants additional inflation-sensitive reserves it is unlikely to need this year.
I Bonds can be more plausible in that second layer because the household is not depending on the bond during its first 12 months.
Example: planned purchase in three years
A saver wants $10,000 for a major purchase three years from now. An I Bond can protect part of the money from inflation, but redeeming at year three would still trigger the three-month interest penalty.
Compare that penalty and future-rate uncertainty with high-yield savings, CDs, and Treasury bills before deciding.
I Bond rates respond to inflation rather than ordinary bank competition
A high-yield savings APY can rise or fall based on market rates and bank pricing. I Bond inflation rates change according to CPI-U movements under the Treasury formula.
Neither product is guaranteed to have the higher yield over every future period.
The fixed rate matters more for long holding periods
A bond purchased with a 0.90% fixed component keeps that fixed component for life. Future new I Bonds might have a higher or lower fixed rate.
For long-term holders, the fixed rate can meaningfully affect returns across many inflation resets.
I Bonds are backed by the U.S. government
Treasury savings bonds are obligations of the United States and are backed by the full faith and credit of the U.S. government.
They are not FDIC-insured bank deposits because the issuer is the Treasury rather than a bank.
Taxes are different from bank savings interest
I Bond interest is subject to federal income tax but is generally exempt from state and local income tax under current federal rules.
Tax can usually be deferred until redemption or final maturity unless the owner elects to report interest annually. Qualified education use can have special federal tax treatment when requirements are met.
TreasuryDirect account access is part of the product
Electronic I Bonds are held in TreasuryDirect. The website is the official federal platform for buying and redeeming U.S. savings bonds.
Keep login and bank information current. TreasuryDirect currently warns that some account-unlock and banking-information changes can take significant processing time.
Do not put the whole emergency fund in I Bonds at once
A saver can build an I Bond ladder gradually. Buy one portion this year while keeping enough bank savings liquid, then add more after the first batch has passed the one-year lock.
Over time, older I Bonds become redeemable while newer purchases remain locked.
For the liquid side of the reserve, How Much Emergency Savings Do You Need? explains how to size emergency cash before adding less-liquid layers.
Compare I Bonds with high-yield savings
A high-yield savings account offers much better immediate liquidity and a simple variable APY. I Bonds offer inflation-linked interest and a fixed component but impose the 12-month lock and potential early-redemption penalty.
Use the product whose liquidity matches the goal.
A practical I Bond checklist
- Keep near-term emergency cash outside the one-year lock.
- Check the current fixed and composite rates before buying.
- Stay within the $10,000 electronic annual purchase limit for the applicable owner.
- Remember that the first 12 months are not liquid.
- Include the three-month interest penalty when planning redemption before five years.
- Keep TreasuryDirect account and bank information current.
- Review federal and state tax treatment for your situation.
Bottom line
I Bonds currently combine a permanent fixed rate with an inflation component that resets every six months. Bonds issued from May through October 2026 earn a 4.26% composite rate for their first six months, including a 0.90% fixed rate. You can buy up to $10,000 electronically per calendar year, cannot redeem for the first 12 months, and lose the latest three months of interest if you redeem before five years. Those rules make I Bonds better suited to medium- and long-term inflation-sensitive savings than to immediate emergency cash.
This article was prepared using current U.S. Treasury I Bond guidance, interest-rate information, and the May 1, 2026 savings-bond rate announcement. Rates and TreasuryDirect procedures can change.
I Bonds can become more liquid over time
The one-year lock applies from each bond’s issue date. If you buy bonds in different years or months, older purchases become redeemable while newer ones remain locked.
That staggered structure can create a ladder in which some inflation-linked savings is always past the minimum holding period.
I Bonds can become more liquid over time
The one-year lock applies from each bond’s issue date. If you buy bonds in different years or months, older purchases become redeemable while newer ones remain locked.
That staggered structure can create a ladder in which some inflation-linked savings is always past the minimum holding period.
I Bonds can become more liquid over time
The one-year lock applies from each bond’s issue date. If you buy bonds in different years or months, older purchases become redeemable while newer ones remain locked.
That staggered structure can create a ladder in which some inflation-linked savings is always past the minimum holding period.
I Bonds can become more liquid over time
The one-year lock applies from each bond’s issue date. If you buy bonds in different years or months, older purchases become redeemable while newer ones remain locked.
That staggered structure can create a ladder in which some inflation-linked savings is always past the minimum holding period.