Treasury Raises Series I Bond Rate to 5.51% Through April 2027

The U.S. Department of the Treasury has increased the annual interest rate on newly purchased Series I savings bonds to 5.51% for the six-month period beginning Nov. 1 and ending April 30, 2027. The new rate replaces the previous 4.26% yield available through Oct. 31, reflecting updated inflation data and a higher fixed-rate component.

The new composite rate consists of a 4.08% variable rate and a 1.40% fixed rate, according to the Treasury. The fixed component represents an increase from the 0.90% announced in April and marks its highest level since 2006.

The latest adjustment comes after I bond rates reached a record 9.62% in May 2022, when inflation surged following the pandemic. Demand subsequently weakened as inflation cooled and interest rates on the government-backed savings product declined.

However, rising consumer prices have renewed interest in inflation-protected savings instruments. David Enna, founder of Tipswatch.com, which monitors Treasury inflation-protected securities and I bond rates, said the latest terms have improved the product's appeal.

"I bonds are a lot more attractive at this point," said David Enna, founder of Tipswatch.com.

Inflation data provide important context for the Treasury's decision. The Consumer Price Index increased 3.7% in September 2026 compared with the same month a year earlier, accelerating from 3.4% in August, according to the Bureau of Labor Statistics.

Economists attributed some of September's price increases to higher gasoline and energy costs associated with the Iran war. President Donald Trump's tariffs, investment in artificial intelligence data centers and travel demand have also contributed to upward price pressures.

A New York Federal Reserve survey released in early October found that consumers expected inflation to reach 3.9% over the following year. That represented the highest one-year inflation expectation in more than three years.

Series I bonds combine a variable interest component tied to inflation with a fixed component established by the Treasury. The agency updates both components every six months, in May and November.

The variable portion uses the percentage change in the Consumer Price Index over a six-month period. Once an investor purchases a bond, that variable rate remains in effect for six months, even when the Treasury announces a new rate.

By contrast, the fixed rate remains unchanged throughout the bond's ownership period. The Treasury does not publicly disclose its precise methodology for determining adjustments to this component.

Ken Tumin, founder of DepositQuest.com, which tracks I bond rates and other deposit accounts, discussed one possible factor behind the fixed-rate calculation.

"There's some uncertainty there," said Ken Tumin, founder of DepositQuest.com.

Some experts believe inflation-adjusted yields on five-year Treasury Inflation-Protected Securities could influence the fixed component, according to Tumin.

Existing bondholders will not automatically receive the newly announced 5.51% rate. Their returns adjust according to the six-month schedule determined by their original purchase dates.

For example, someone who purchased I bonds in March with a 3.12% variable rate and a 0.90% fixed rate would see the variable portion change to 3.34% after six months, based on the rate announced in April 2026. The original 0.90% fixed component would remain unchanged.

Investors can earn interest on I bonds for up to 30 years, although they may redeem them earlier. The Treasury requires owners to hold the bonds for at least one year before cashing them in. Investors who redeem before completing five years forfeit their final three months of interest.