I bond rates · May 2026 – October 2026
I Bond Rate for May 2026 – October 2026
Announced May 2026 1 by the Treasury: a fixed rate of 0.90%, a semiannual inflation rate of 1.67%, and the 4.26% composite those two produce.
A bond bought in this period earned 4.26% for its first six months and keeps its 0.90% fixed rate for life. This is the current period, so that is also what it earns now.
The May 2026 – October 2026 composite, worked
Treasury's formula: fixed rate + (2 × semiannual inflation rate) + (fixed rate × semiannual inflation rate), rounded to four decimals.
What this cohort has earned since
Its fixed rate never changes; each later period applies that period's inflation rate to it. Rates take effect on the bond's own six-month anniversaries, not on the announcement date.
| Period | Inflation rate | This cohort's fixed | Composite |
|---|---|---|---|
| May 2026 – October 2026 | 1.67% | 0.90% | 4.26% |
Source: TreasuryDirect — I bonds interest rates (fixed-rate and inflation-rate history). Composites are recomputed with Treasury's formula and checked against Treasury's published figures before publication. Bonds cashed before five years forfeit the last three months of interest.
Informational only, not financial or tax advice.
Last reviewed: May 2026 announcement · snapshot built 2026-10-26 from treasurydirect.gov.
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