Series I bond rate rises to 5.51% for six months

The U.S. Department of the Treasury said on Monday that newly purchased Series I savings bonds will earn a 5.51% annual return from Nov. 1, 2026 through Apr. 30, 2027. The composite rate combines a 4.08% inflation‑linked component with a 1.40% fixed portion, the highest fixed rate for an I‑bond since 2006. The announcement comes as consumer prices remain elevated and investors look for low‑risk ways to preserve purchasing power.

What the Treasury announced

According to a release cited by CNBC, the Treasury set the six‑month I‑bond rate at 5.51% effective Nov. 1. The rate replaces the 4.26% composite yield that applied to bonds bought through Oct. 31. The fixed rate rose from 0.90% to 1.40%, while the variable portion reflects the latest six‑month change in the Consumer Price Index (CPI).

How the 5.51% rate is built

I‑bonds always consist of two parts:

• Variable rate – tied to the CPI over the previous six months. For this period the Treasury calculated a 4.08% inflation component.
• Fixed rate – set by the Treasury and locked in for the life of the bond. This cycle’s fixed rate is 1.40%.

The two figures are added together and rounded to produce the composite rate of 5.51%. The variable portion stays the same for the first six months after purchase, even if the Treasury announces a new rate later. The fixed portion never changes for that bond.

Why the change matters to savers and investors

Series I bonds are marketed as a near‑risk‑free way to earn a return that keeps pace with inflation. At 5.51% they now outpace most traditional savings accounts and many short‑term certificates of deposit, while still offering federal tax advantages and a guaranteed principal.

For comparison:

• Average 12‑month CD rates are hovering around 4.2%.
• High‑yield savings accounts typically pay 4.0%‑4.5%.
• U.S. Treasury Inflation‑Protected Securities (TIPS) for a five‑year term are yielding roughly 3.9% after inflation adjustment.

Because the fixed component is now 1.40%, the bond’s return will remain attractive even if inflation eases later in the year. That could make I‑bonds a compelling alternative to other interest‑rate products, especially as credit‑card interest‑rate caps are being discussed in the policy arena.

What to watch as the rate evolves

The Treasury updates I‑bond rates every May and November. Investors should keep an eye on two drivers:

1. Inflation trends – The variable portion mirrors the CPI change over the prior six months. Any slowdown or acceleration in consumer prices will shift the next variable rate.
2. Fixed‑rate policy – While the Treasury does not explain its methodology, analysts suggest the fixed rate may be linked to real yields on five‑year TIPS. Shifts in the bond market could influence the next fixed‑rate announcement.

Current data show the CPI rose 3.7% year‑over‑year in September, up from 3.4% in August, partly due to higher energy costs linked to the Iran conflict and robust demand for travel and AI data centers. If those pressures persist, the variable component could stay near the 4% range, keeping the composite rate above 5%.

Existing I‑bond holders will see the variable portion adjust at the six‑month mark after their purchase, but their fixed rate will stay locked. New buyers, however, benefit from the higher fixed rate immediately.

Key takeaways

• Effective Nov. 1, 2026 – Apr. 30, 2027, the composite I‑bond rate is 5.51%.
• Variable component: 4.08% (inflation‑linked).
• Fixed component: 1.40% – highest since 2006.
• Rate replaces the 4.26% composite that applied through Oct. 31, 2026.
• I‑bonds cannot be redeemed for the first year; early redemption before five years forfeits the last three months of interest.

Sources

• Treasury Department announces new Series I bond rate of 5.51% for the next six months — cnbc.com