I bond fixed rates since 1998, and what each group earns now

The full table

Each row is one sales window. The fixed rate is the one printed in the Treasury's rate history workbook (TreasuryDirect); the last column applies this month's inflation part to it with the Treasury's formula. When a window shows two rates, bonds issued in different months of that window have not yet reached the same rate period.

What the numbers show

The first I bonds, in 1998, came with a fixed rate of 3.40 %. The rate climbed to 3.60 % for May 2000 to October 2000, then fell over the following decade. Stretches of zero fixed rates ran from May 2008 to October 2008, November 2010 to October 2013, November 2014 to October 2015, November 2016 to October 2017, May 2020 to October 2022. Since November 2022 the fixed rate has been positive in every window, 0.90 % in the current one.

A fixed rate is a real return: it is what the bond earns above inflation as measured by the CPI-U. A bond at 3.60 % doubles its purchasing power in roughly 20 years on top of keeping up with prices. A bond at zero only keeps up. Over the 30 years of a bond, that difference outweighs any single six-month inflation figure.

Reading your bond's window

The issue month is printed on a paper bond, top right, and shown in the bond details of a TreasuryDirect account. Windows run from May to October and from November to April, except the first one, which started in September 1998. A bond issued in October 2022 belongs to the May to October 2022 window, with a fixed rate of 0.00 %; one issued a month later, in November 2022, got 0.40 %. That one-month gap is the main reason two I bonds bought the same autumn can earn different rates for 30 years.

The calculator above shows every rate period of a bond with its composite rate. For the dollar value, use the value table or the home page calculator; for the rates of the current window and the November announcement, see I bond rates and the next rate.

Same inflation, different fixed rates

Two paper bonds of $1,000 make the point in dollars. One was bought in May 2007 with a fixed rate of 1.30 %; the other in May 2011 with 0.00 %. Since May 2011 both have received exactly the same inflation part at every reset, because they share the May and November schedule. The 2007 bond is worth $2,136.80 on the first of October 2026, the 2011 bond $1,521.20. Part of the gap is the four extra years of the older bond; the rest is the fixed rate, applied at each of the 31 rate periods the two bonds have shared. Measured against its price, the 2007 bond has multiplied its value by 2.14 and the 2011 bond by 1.52.

The same arithmetic applies in the other direction to anyone choosing between buying in the last days of a window and the first days of the next one. Once the inflation part of the next announcement is known, as it is a few weeks ahead from the CPI-U, the only open question is whether the next fixed rate will be higher or lower than the current 0.90 %. The Treasury answers it on the announcement day and not before.

Bonds near the end of their 30 years

I bonds from the first windows of 1998 and 1999 reach final maturity 30 years after issue, from September 2028 on. They earn their fixed rate plus inflation until that month, then nothing. An electronic bond is paid out automatically at final maturity; a paper one has to be cashed, and its interest is taxable in the year it matures. The matured bonds page explains what to do with a bond that has stopped earning, and the early cashing page covers the other end of a bond's life.