The interest rate on a Series I savings bond changes every 6 months, based on inflation. The rate can go up. The rate can go down.
I bonds earn interest until the first of these events: You cash in the bond or the bond reaches 30 years old.
I bonds earn a combined rate of interest
the interest on I bonds is a combination of
- a fixed rate
- a inflation rate
Current Interest Rate
Series I Savings Bonds
4.28%
This includes a fixed rate of 1.30%
For I bonds issued May 1, 2024 to October 31, 2024.
Fixed rate
You know the fixed rate of interest that you will get for your bond when you buy the bond. The fixed rate never changes.
We announce the fixed rate every May 1 and November 1. That fixed rate then applies, for the life of the bond, to all I bonds that we issue during the next 6 months.
The fixed rate is an annual rate.
Inflation rate
The inflation rate changes every 6 months.
We set the inflation rate every May 1 and November 1. We base the inflation rate on changes in the non-seasonally adjusted Consumer Price Index for all Urban Consumers (CPI-U) for all items, including food and energy.
Combined rate
The actual rate of interest for an I bond is calculated from the fixed rate and the inflation rate. The combined rate changes every 6 months. It can go up or down.
I bonds protect you from inflation because when inflation increases, the combined rate increases.
Because inflation can go up or down, we can have deflation (the opposite of inflation). Deflation can bring the combined rate down below the fixed rate (as long as the fixed rate itself is not zero). However, if the inflation rate is so negative that it would pull the combined rate below zero, we don't let that happen. We stop at zero.
The combined rate is sometimes called the "composite rate" or the "earnings rate."
Look at the example below to see how we combine the fixed rate and the inflation rate to get the combined rate.
An example
The composite rate for I bonds issued from May 2024 through October 2024 is 4.28%.
Here's how we got that rate:
| Fixed rate | 1.30% |
|---|---|
| Semiannual (1/2 year) inflation rate | 1.48% |
| Composite rate formula: [Fixed rate + (2 x semiannual inflation rate) + (fixed rate x semiannual inflation rate)] | [0.0130 + (2 x 0.0148) + (0.0130 x 0.0148)] |
| Gives a composite rate of | [0.0130 + 0.0296 + 0.0001924] |
| Adding the parts gives | 0.0427924 |
| Rounding gives | 0.0428 |
| Turning the decimal number to a percentage gives a composite rate of | 4.28% |
Interest rate changes depend on when we issued the bond
Although we announce the new rates in May and November, the date when the rate changes for your bond is every 6 months from the issue date of your bond. Use this table to understand when each new rate begins to apply to your I bond.
| If we issued your bond in | Your interest rate changes every |
|---|---|
| January | July 1 and January 1 |
| February | August 1 and February 1 |
| March | September 1 and March 1 |
| April | October 1 and April 1 |
| May | November 1 and May 1 |
| June | December 1 and June 1 |
| July | January 1 and July 1 |
| August | February 1 and August 1 |
| September | March 1 and September 1 |
| October | April 1 and October 1 |
| November | May 1 and November 1 |
| December | June 1 and December 1 |
The interest gets added to the bond's value
I bonds earn interest from the first day of the month you buy them.
Twice a year, we add all the interest the bond earned in the previous 6 months to the main (principal) value of the bond.
That gives the bond a new value (old value + interest earned).
Over the next 6 months, we apply the new interest rate to that entire new value.
This is called semiannually compounding (adding value 2 times a year). That way, your money grows not just from the interest percentage but from the fact that the interest is calculated on a growing balance.
How do you find the current value of an I bond? If the bond is in TreasuryDirect, look in your account there. If the bond is paper, use the Savings Bond Calculator.
Note: For bonds less than 5 years old, values shown in TreasuryDirect and the Calculator don’t include the last 3 months of interest. That’s because if you cash a bond before 5 years, we don’t pay you the final 3 months of interest.
What have interest rates been for I bonds?
We've put all the rates together in one chart – fixed rate, inflation rate, and combined rate. You can look up a specific bond there and see its entire history. You will probably have to enlarge the chart to view a particular row. We also have a Series I Bond rate history chart.
Below, we show you historical rates in separate tables.
Fixed rates
The fixed rate that we set each May and November applies to all bonds we issue in the 6 months following the date when we set the rate. The fixed rate applies for the life of the bond.
| Date the fixed rate was set | Fixed rate for bonds issued in the six months after that date |
|---|---|
| May 1, 2024 | 1.30% |
| November 1, 2023 | 1.30% |
| May 1, 2023 | 0.90% |
| November 1, 2022 | 0.40% |
| May 1, 2022 | 0.00% |
| November 1, 2021 | 0.00% |
| May 1, 2021 | 0.00% |
| November 1, 2020 | 0.00% |
| May 1, 2020 | 0.00% |
| November 1, 2019 | 0.20% |
| May 1, 2019 | 0.50% |
| November 1, 2018 | 0.50% |
| May 1, 2018 | 0.30% |
| November 1, 2017 | 0.10% |
| May 1, 2017 | 0.00% |
| November 1, 2016 | 0.00% |
| May 1, 2016 | 0.10% |
| November 1, 2015 | 0.10% |
| May 1, 2015 | 0.00% |
| November 1, 2014 | 0.00% |
| May 1, 2014 | 0.10% |
| November 1, 2013 | 0.20% |
| May 1, 2013 | 0.00% |
| November 1, 2012 | 0.00% |
| May 1, 2012 | 0.00% |
| November 1, 2011 | 0.00% |
| May 1, 2011 | 0.00% |
| November 1, 2010 | 0.00% |
| May 1, 2010 | 0.20% |
| November 1, 2009 | 0.30% |
| May 1, 2009 | 0.10% |
| November 1, 2008 | 0.70% |
| May 1, 2008 | 0.00% |
| November 1, 2007 | 1.20% |
| May 1, 2007 | 1.30% |
| November 1, 2006 | 1.40% |
| May 1, 2006 | 1.40% |
| November 1, 2005 | 1.00% |
| May 1, 2005 | 1.20% |
| November 1, 2004 | 1.00% |
| May 1, 2004 | 1.00% |
| November 1, 2003 | 1.10% |
| May 1, 2003 | 1.10% |
| November 1, 2002 | 1.60% |
| May 1, 2002 | 2.00% |
| November 1, 2001 | 2.00% |
| May 1, 2001 | 3.00% |
| November 1, 2000 | 3.40% |
| May 1, 2000 | 3.60% |
| November 1, 1999 | 3.40% |
| May 1, 1999 | 3.30% |
| November 1, 1998 | 3.30% |
| September 1, 1998 | 3.40% |
Inflation rates
The inflation rate that we set each May and November applies for 6 months to all I bonds that we ever issued.
| Date the inflation rate was set | Inflation rate for all I bonds issued for six months (starting in that bond's next interest start month - see the table of months higher on this page) |
|---|---|
| May 1, 2024 | 1.48% |
| November 1, 2023 | 1.97% |
| May 1, 2023 | 1.69% |
| November 1, 2022 | 3.24% |
| May 1, 2022 | 4.81% |
| November 1, 2021 | 3.56% |
| May 1, 2021 | 1.77% |
| November 1, 2020 | 0.84% |
| May 1, 2020 | 0.53% |
| November 1, 2019 | 1.01% |
| May 1, 2019 | 0.70% |
| November 1, 2018 | 1.16% |
| May 1, 2018 | 1.11% |
| November 1, 2017 | 1.24% |
| May 1, 2017 | 0.98% |
| November 1, 2016 | 1.38% |
| May 1, 2016 | 0.08% |
| November 1, 2015 | 0.77% |
| May 1, 2015 | -0.80% |
| November 1, 2014 | 0.74% |
| May 1, 2014 | 0.92% |
| November 1, 2013 | 0.59% |
| May 1, 2013 | 0.59% |
| November 1, 2012 | 0.88% |
| May 1, 2012 | 1.10% |
| November 1, 2011 | 1.53% |
| May 1, 2011 | 2.30% |
| November 1, 2010 | 0.37% |
| May 1, 2010 | 0.77% |
| November 1, 2009 | 1.53% |
| May 1, 2009 | -2.78% |
| November 1, 2008 | 2.46% |
| May 1, 2008 | 2.42% |
| November 1, 2007 | 1.53% |
| May 1, 2007 | 1.21% |
| November 1, 2006 | 1.55% |
| May 1, 2006 | 0.50% |
| November 1, 2005 | 2.85% |
| May 1, 2005 | 1.79% |
| November 1, 2004 | 1.33% |
| May 1, 2004 | 1.19% |
| November 1, 2003 | 0.54% |
| May 1, 2003 | 1.77% |
| November 1, 2002 | 1.23% |
| May 1, 2002 | 0.28% |
| November 1, 2001 | 1.19% |
| May 1, 2001 | 1.44% |
| November 1, 2000 | 1.52% |
| May 1, 2000 | 1.91% |
| November 1, 1999 | 1.76% |
| May 1, 1999 | 0.86% |
| November 1, 1998 | 0.86% |
| September 1, 1998 | 0.62% |
Current composite rates
The table below shows the current composite rate for all I bonds. Each composite rate is a yearly rate that applies for 6 months.
| Period when you bought your I bond | Composite rate for your 6 month earning period starting during May 2024 through October 2024 | |
|---|---|---|
| From | Through | |
| May 2024 | Oct. 2024 | 4.28% |
| Nov. 2023 | Apr. 2024 | 4.28% |
| May 2023 | Oct. 2023 | 3.87% |
| Nov. 2022 | Apr. 2023 | 3.37% |
| May 2022 | Oct. 2022 | 2.96% |
| Nov. 2021 | Apr. 2022 | 2.96% |
| May 2021 | Oct. 2021 | 2.96% |
| Nov. 2020 | Apr. 2021 | 2.96% |
| May 2020 | Oct. 2020 | 2.96% |
| Nov. 2019 | Apr. 2020 | 3.16% |
| May 2019 | Oct. 2019 | 3.47% |
| Nov. 2018 | Apr. 2019 | 3.47% |
| May 2018 | Oct. 2018 | 3.26% |
| Nov. 2017 | Apr. 2018 | 3.06% |
| May 2017 | Oct. 2017 | 2.96% |
| Nov. 2016 | Apr. 2017 | 2.96% |
| May 2016 | Oct. 2016 | 3.06% |
| Nov. 2015 | Apr. 2016 | 3.06% |
| May 2015 | Oct. 2015 | 2.96% |
| Nov. 2014 | Apr. 2015 | 2.96% |
| May 2014 | Oct. 2014 | 3.06% |
| Nov. 2013 | Apr. 2014 | 3.16% |
| May 2013 | Oct. 2013 | 2.96% |
| Nov. 2012 | Apr. 2013 | 2.96% |
| May 2012 | Oct. 2012 | 2.96% |
| Nov. 2011 | Apr. 2012 | 2.96% |
| May 2011 | Oct. 2011 | 2.96% |
| Nov. 2010 | Apr. 2011 | 2.96% |
| May 2010 | Oct. 2010 | 3.16% |
| Nov. 2009 | Apr. 2010 | 3.26% |
| May 2009 | Oct. 2009 | 3.06% |
| Nov. 2008 | Apr. 2009 | 3.67% |
| May 2008 | Oct. 2008 | 2.96% |
| Nov. 2007 | Apr. 2008 | 4.18% |
| May 2007 | Oct. 2007 | 4.28% |
| Nov. 2006 | Apr. 2007 | 4.38% |
| May 2006 | Oct. 2006 | 4.38% |
| Nov. 2005 | Apr. 2006 | 3.97% |
| May 2005 | Oct. 2005 | 4.18% |
| Nov. 2004 | Apr. 2005 | 3.97% |
| May 2004 | Oct. 2004 | 3.97% |
| Nov. 2003 | Apr. 2004 | 4.08% |
| May 2003 | Oct. 2003 | 4.08% |
| Nov. 2002 | Apr. 2003 | 4.58% |
| May 2002 | Oct. 2002 | 4.99% |
| Nov. 2001 | Apr. 2002 | 4.99% |
| May 2001 | Oct. 2001 | 6.00% |
| Nov. 2000 | Apr. 2001 | 6.41% |
| May 2000 | Oct. 2000 | 6.61% |
| Nov. 1999 | Apr. 2000 | 6.41% |
| May 1999 | Oct. 1999 | 6.31% |
| Nov. 1998 | Apr. 1999 | 6.31% |
| Sept. 1998 | Oct. 1998 | 6.41% |
