Part of the interest from I bonds is tied to the Consumer Price Index.NoDerog from Getty Images Signature; CanvaI bonds, or series I bonds, are savings bonds from the United States Treasury. This is a relatively new Treasury security that was introduced in 1998 by the U.S. government to ‘encourage Americans to save for the future while protecting their savings from inflation.’These bonds can be bought for as little as $50. Artwork on the bonds honors distinguished Americans like Dr. Martin Luther King, Jr.