A Series I savings bond bought today pays a composite rate of 4.26%. That number is the one in every headline, and it is the least durable thing about the bond.
The 4.26% is two rates welded together: a fixed rate of 0.90% and an inflation-adjusted rate of 3.34% annualized. Per TreasuryDirect, the inflation component resets every six months for the life of the bond — so does everyone else's, whenever they bought. The fixed rate never changes. It is the only part of the deal your purchase date decides permanently, and it rides along for up to 30 years.
Right now that distinction has a price tag on it.
What the November 1 Reset Is Likely to Do
Treasury resets both components on November 1, 2026. The fixed rate tracks trailing real yields on 5-year Treasury Inflation-Protected Securities, and those yields have moved sharply: the 5-year TIPS real yield reached 2.13% in early August, up 102 basis points since late February. Tipswatch, which tracks the reset closely, projects the new fixed rate will land at 1.30%, up from 0.90%.
The variable side is heading the same direction but matters far less. With five of the six qualifying months reported, inflation had accrued 1.44%, and the November variable rate is projected at roughly 3.4% to 3.5% — a hair above the current 3.34%. August CPI came in at 3.4% annually, with core at 2.4%. The September CPI report on October 14 finalizes that component.
So the projected November bond is better on both counts. But only one of those advantages is permanent. A bond bought in October carries 0.90% above inflation until you sell it. The projected November bond carries 1.30% above inflation until you sell it. That gap is about $40 per year per $10,000, in inflation-adjusted terms, for as long as you hold.
The Case for Not Rushing
The usual reason to buy before a reset is that you lose the year's allocation by waiting. That does not apply here. The $10,000 per person per calendar year limit runs on the calendar, and November and December are still 2026 — waiting preserves the full-year purchase for a likely better fixed rate.
Two honest caveats. First, 1.30% is a projection, not an announcement. Treasury does not publish the formula it uses; the 0.65-of-real-yields relationship is an observed pattern, and Treasury retains discretion. Second, buying later starts the clock later: I bonds cannot be redeemed at all for 12 months, and redeeming before 5 years forfeits the last three months of interest.
The wider signal is worth noting too. A 30-year TIPS auction recently cleared at a 2.973% real yield — the highest in nearly 25 years. Above the $10,000 I bond cap, TIPS are where retirees can actually buy that inflation-adjusted yield at scale.
Practical Takeaways
- Read the two components, not the composite. A 4.26% headline tells you almost nothing about what you are locking in. Ask what the fixed rate is.
- Check the reset calendar before buying. Rates change May 1 and November 1. Buying in the last weeks of a rate period, into a rising-real-yield environment, is the worst timing available.
- Waiting until November costs you nothing in 2026 allocation. The annual limit is per calendar year, per Social Security number.
- Do not commit money you may need within 12 months. There is no early redemption at all in year one, and a three-month interest penalty before year five.
- Treat 1.30% as likely, not certain. If the fixed rate comes in lower, you have still given up only a few weeks of interest, not a 30-year rate.
Sources: TreasuryDirect – Series I Savings Bonds; Tipswatch.com, "The I Bond's fixed rate is going higher. But how much?" (August 9, 2026); Tipswatch.com, "U.S. inflation holds at 3.4% for August" (September 11, 2026); Bureau of Labor Statistics, Consumer Price Index, August 2026.