September 13, 2023

Comparing I Bonds to Inflation

If you hold I bonds for five years or longer you will get the full interest when you redeem them. As of September 1, 2023, there are 240 I bonds that are older than five years. These are the I bonds purchased from September 1998 through August 2018, the five year mark as of September 2023. Of these 240 I bonds, 164 will provide a real return if you redeem them in August. In other words, 164 of these I bonds have grown in their values to exceed their inflation-adjusted purchase prices and the remaining 76 are lagging behind inflation.

For I bonds purchased each month starting from September 1998 through August 2018, the chart below shows how much the bonds had grown in values compared to the growth in inflation for the same period. The variance shown in the graph is the difference between the bond value and the inflation-adjusted purchase price on 9/1/2023 as a percentage of the inflation-adjusted purchase price. So it is the cumulative real growth from the purchase date through 9/1/2023 (not annual growth). As an example, as on 9/1/2023, a $10,000 I bond purchased in September 1998 had grown 130.15% over its inflation-adjusted purchase price.

Use the Next and Previous buttons to move around the purchase dates of bonds.

The chart below shows the number of I bonds older than five years above and below their inflation-adjusted purchase prices for each month from January 2020 through September 2023. For example, in January 2020, there were 196 I bonds older than 5 years. Out of them, 193 had grown in their values to exceed their respective purchase prices adjusted for inflation, and only three were below those levels. On the other hand, in September 2023, 164 out of a total of 240 I bonds (68%) older than five years were above and 76 were below their inflation-adjusted purchase prices.