A Series I Bond is a low-risk investment offered by the United States government, designed to provide investors with protection from inflation and a fixed return on the original investment. These bonds are not marketable, meaning they cannot be bought or sold in the secondary markets, instead, investors must apply for the bond directly from the government, and the bond will last for 30 years, 20 years from the date of purchase and a 10-year extended period.

Series I Bonds earn a fixed rate of interest, determined by the U.S. Treasury and paid out every six months. This fixed rate is determined at the time of purchase and will never change. What is unique about Series I Bonds is that in addition to earning this fixed rate of interest, the bond will also earn a variable inflation rate, adjusted each May and November. This rate is determined by looking at the Consumer Price Index (CPI) which calculates the current inflation rate. The rate is determined by how much the CPI has changed over a six-month period. Therefore, the inflation rate earned by a Series I Bond can potentially increase or decrease over time.

Series I Bonds offer investors an excellent way to save for the future with a low-risk investment that gives protection from inflation, as well as a fixed return on the original investment. With a maximum certification amount of $10,000 per calendar year and a minimum denomination of $50, investors of all sizes can take advantage of the security and stability of a Series I Bond.