As of October 2023, the fixed rate for I bonds is 0.90%. The composite rate for I bonds issued from May 2023 through October 2023 is 4.30%, which combines the fixed rate of 0.90% with the semiannual inflation rate of 3.38% as measured by the Consumer Price Index for all Urban Consumers (CPI-U). The composite rate applies for the first six months after the issue date. The Treasury sets new I bond interest rates in May and November. It is important to note that the fixed rate of an I bond never changes.