Treasury will announce new I bond rates on November 1, so bonds bought through October 31 are the last to carry the current fixed rate of 0.90%. That fixed rate stays with a bond for as long as it is held. The 4.26% composite rate printed beside it does not, and the difference decides what an October buyer is really getting.
What an October I bond purchase locks in
Treasury’s rate page lists a fixed rate of 0.90% for I bonds issued from May 1, 2026 through October 31, 2026. Treasury says each I bond keeps one fixed rate for its life. A bond issued on October 31 holds 0.90% for as long as it is owned, whatever number is announced the next day.
The window closes on a schedule, not on a whim. Treasury says it announces the fixed rate every May 1 and November 1, which puts the next announcement on November 1, 2026. Bonds issued from that date carry the new fixed rate, and it could land above or below 0.90%.
For a saver weighing whether to buy before the end of the month or wait, the choice comes down to one number. Buying by October 31 locks 0.90% in. Waiting means accepting a fixed rate that nobody outside Treasury can name yet, and the cost of waiting is the risk that it comes in lower, which sits right beside the chance that it comes in higher.
Retirement deadlines, in your inbox: Miss an enrollment or claim deadline and the money can be gone. Join the Retirement Money Brief and we’ll send you our 2026 Government Check Reality Tracker as a welcome gift.
Get the Brief + the check tracker →
We may earn a commission from links on this page.
Treasury’s page showed no November rates as of October 28, so there is nothing to set against the 0.90% figure today. The announcement comes only twice a year, which is why the October purchase window has a hard edge and does not slide gradually from one rate to the next.
Why the 4.26% composite rate does not lock
Treasury lists a composite rate of 4.26% for the six-month earning period running May 2026 through October 2026. The page says the overall rate is calculated from a fixed rate and an inflation rate, and the 4.26% already includes the fixed 0.90%. The rest of the composite comes from the inflation side.
Only the fixed piece is permanent. Treasury sets the inflation rate on the same May 1 and November 1 schedule, and each bond’s own rate changes every six months from its issue date. The overall rate can rise or fall at each reset, so a buyer who reads 4.26% as a number that will last is misreading how the bond works.
The split explains why the rate quoted for I bonds can change from one half-year to the next while the fixed rate on a given bond never does. The fixed 0.90% is the steady part of the arrangement. The inflation part is rebuilt twice a year, and it follows whatever Treasury announces on those two dates.
Prices supply the backdrop. The Bureau of Labor Statistics reported on October 14 that the Consumer Price Index rose 3.7 percent over the 12 months ending September, with a 0.6 percent gain in September alone and 2.6 percent excluding food and energy. Those are consumer-price figures in general. Treasury sets the I bond’s inflation rate on its own timetable.
What waiting for November’s fixed rate puts at risk
The rate backdrop is unsettled. On October 28, the Federal Reserve’s policy committee kept its target range at 3-3/4 to 4 percent on a 10-2 vote. Lisa D. Cook and Beth M. Hammack voted against, preferring a quarter-point increase, so two members wanted rates higher, not lower.
Treasury’s I bond page does not say how it will set the November fixed rate or whether the Fed’s decision enters into it. That leaves the 0.90% as the only fixed number a buyer can see before the month ends. Anyone treating the Fed vote as a forecast for the new I bond fixed rate is guessing.
Holding rules apply to every issue, whichever rate is announced. Treasury says an I bond can be redeemed once it is 12 months old, and cashing out before five years forfeits the last three months of interest. Money that may be needed within a year cannot go into an I bond at all, and money needed inside five years takes a three-month interest cut.
That is why the October deadline matters most to savers with cash they will leave alone. The 0.90% is the only piece that stays put, so it counts for more the longer a bond is held. A saver who expects to cash out the day the 12 months end is mostly buying the composite rate, which resets every six months anyway.
Bonds are bought through TreasuryDirect, the Treasury’s own savings bond site, and the October issue date is what counts for the 0.90% fixed rate. A purchase made on or before October 31 gets it. A purchase made on November 1 or later gets whatever fixed rate Treasury sets that day.
What stays open until November 1 is the number itself. Treasury has said when it will announce the next fixed rate, but not what it will be, so buyers cannot compare 0.90% against a figure that does not yet exist. Anyone who buys by October 31 accepts 0.90% without knowing whether November’s fixed rate will be better.
Anyone who skips October takes the other side of the same bet. The fixed rate on a November bond will be whatever Treasury announces that day, and it cannot be changed afterward. On either side of the calendar, the composite rate is a six-month starting point and never a promise.
Buy the I bond before October 31, or wait for the November rate?
A saver who picks a rate in a hurry can end up with money tied up for 12 months at a fixed rate that November would have beaten, or with cash sitting in an account that pays almost nothing while the decision drags on.
Make Your Savings Pay You lays out the safe places side by side, including I bonds whose rate adjusts with inflation every six months, and keeps every dollar insured, even above $250,000 at one bank. It comes with a ladder to copy, so money comes due on a schedule instead of all at once.
Get the safe-savings guide with the I bond and Treasury bill ladder →
This article was produced with AI assistance and edited for accuracy against the sources linked above.
