Treasury resets the Series I savings bond inflation rate on Sunday, Nov 1, 2026 using its published formula: the semiannual inflation rate is the change in the not-seasonally-adjusted CPI-U from Mar 2026 to Sep 2026, rounded to 0.01%; the variable rate is twice that; the composite rate is fixed + 2 × semiannual + fixed × semiannual. With CPI-U Mar 2026 = 330.213 (actual) and Sep 2026 at 336.94 (actual), the semiannual rate is 2.04% and the variable rate 4.08%. At the current fixed rate of 0.9% (set for May 1, 2026) the composite would be 5%; the page lets you enter the fixed rate Treasury actually sets. The new-bond rate in force now (announced May 2026, bonds bought May–Oct 2026) is 4.26%: a 0.9% fixed rate plus the 3.34% variable rate. Treasury sets the new rates for May 1 and November 1; Nov 1, 2026 is a Sunday, so the announcement can post on the nearest business day.
Checked against Treasury's published rates: 13 of 13 match to the basis point.
| Announced | CPI-U from → to | Semiannual | Variable | Treasury |
|---|---|---|---|---|
| Nov 2026 | Mar 2026 330.213 → Sep 2026 336.94 | 2.04% | 4.08% | — |
| May 2026 | Sep 2025 324.8 → Mar 2026 330.213 | 1.67% | 3.34% | 1.67% |
| Nov 2025 | Mar 2025 319.799 → Sep 2025 324.8 | 1.56% | 3.12% | 1.56% |
| May 2025 | Sep 2024 315.301 → Mar 2025 319.799 | 1.43% | 2.86% | 1.43% |
| Nov 2024 | Mar 2024 312.332 → Sep 2024 315.301 | 0.95% | 1.9% | 0.95% |
| May 2024 | Sep 2023 307.789 → Mar 2024 312.332 | 1.48% | 2.96% | 1.48% |
| Nov 2023 | Mar 2023 301.836 → Sep 2023 307.789 | 1.97% | 3.94% | 1.97% |
| May 2023 | Sep 2022 296.808 → Mar 2023 301.836 | 1.69% | 3.38% | 1.69% |
| Nov 2022 | Mar 2022 287.504 → Sep 2022 296.808 | 3.24% | 6.48% | 3.24% |
| May 2022 | Sep 2021 274.31 → Mar 2022 287.504 | 4.81% | 9.62% | 4.81% |
| Nov 2021 | Mar 2021 264.877 → Sep 2021 274.31 | 3.56% | 7.12% | 3.56% |
| May 2021 | Sep 2020 260.28 → Mar 2021 264.877 | 1.77% | 3.54% | 1.77% |
| Nov 2020 | Mar 2020 258.115 → Sep 2020 260.28 | 0.84% | 1.68% | 0.84% |
| May 2020 | Sep 2019 256.759 → Mar 2020 258.115 | 0.53% | 1.06% | 0.53% |
| Nov 2019 | Mar 2019 254.202 → Sep 2019 256.759 | 1.01% | 2.02% | — |
| May 2019 | Sep 2018 252.439 → Mar 2019 254.202 | 0.7% | 1.4% | — |
| Nov 2018 | Mar 2018 249.554 → Sep 2018 252.439 | 1.16% | 2.32% | — |
| May 2018 | Sep 2017 246.819 → Mar 2018 249.554 | 1.11% | 2.22% | — |
| Nov 2017 | Mar 2017 243.801 → Sep 2017 246.819 | 1.24% | 2.48% | — |
| May 2017 | Sep 2016 241.428 → Mar 2017 243.801 | 0.98% | 1.96% | — |
| Nov 2016 | Mar 2016 238.132 → Sep 2016 241.428 | 1.38% | 2.76% | — |
| May 2016 | Sep 2015 237.945 → Mar 2016 238.132 | 0.08% | 0.16% | — |
| Nov 2015 | Mar 2015 236.119 → Sep 2015 237.945 | 0.77% | 1.54% | — |
| May 2015 | Sep 2014 238.031 → Mar 2015 236.119 | -0.8% | -1.6% | — |
| Nov 2014 | Mar 2014 236.293 → Sep 2014 238.031 | 0.74% | 1.48% | — |
| May 2014 | Sep 2013 234.149 → Mar 2014 236.293 | 0.92% | 1.84% | — |
| Nov 2013 | Mar 2013 232.773 → Sep 2013 234.149 | 0.59% | 1.18% | — |
| May 2013 | Sep 2012 231.407 → Mar 2013 232.773 | 0.59% | 1.18% | — |
| Nov 2012 | Mar 2012 229.392 → Sep 2012 231.407 | 0.88% | 1.76% | — |
| May 2012 | Sep 2011 226.889 → Mar 2012 229.392 | 1.1% | 2.2% | — |
| Nov 2011 | Mar 2011 223.467 → Sep 2011 226.889 | 1.53% | 3.06% | — |
| May 2011 | Sep 2010 218.439 → Mar 2011 223.467 | 2.3% | 4.6% | — |
| Nov 2010 | Mar 2010 217.631 → Sep 2010 218.439 | 0.37% | 0.74% | — |
| May 2010 | Sep 2009 215.969 → Mar 2010 217.631 | 0.77% | 1.54% | — |
| Nov 2009 | Mar 2009 212.709 → Sep 2009 215.969 | 1.53% | 3.06% | — |
| May 2009 | Sep 2008 218.783 → Mar 2009 212.709 | -2.78% | -5.56% | — |
| Nov 2008 | Mar 2008 213.528 → Sep 2008 218.783 | 2.46% | 4.92% | — |
| May 2008 | Sep 2007 208.49 → Mar 2008 213.528 | 2.42% | 4.84% | — |
| Nov 2007 | Mar 2007 205.352 → Sep 2007 208.49 | 1.53% | 3.06% | — |
| May 2007 | Sep 2006 202.9 → Mar 2007 205.352 | 1.21% | 2.42% | — |
| Nov 2006 | Mar 2006 199.8 → Sep 2006 202.9 | 1.55% | 3.1% | — |
| May 2006 | Sep 2005 198.8 → Mar 2006 199.8 | 0.5% | 1% | — |
| Nov 2005 | Mar 2005 193.3 → Sep 2005 198.8 | 2.85% | 5.7% | — |
| May 2005 | Sep 2004 189.9 → Mar 2005 193.3 | 1.79% | 3.58% | — |
| Nov 2004 | Mar 2004 187.4 → Sep 2004 189.9 | 1.33% | 2.66% | — |
| May 2004 | Sep 2003 185.2 → Mar 2004 187.4 | 1.19% | 2.38% | — |
| Nov 2003 | Mar 2003 184.2 → Sep 2003 185.2 | 0.54% | 1.08% | — |
| May 2003 | Sep 2002 181 → Mar 2003 184.2 | 1.77% | 3.54% | — |
| Nov 2002 | Mar 2002 178.8 → Sep 2002 181 | 1.23% | 2.46% | — |
| May 2002 | Sep 2001 178.3 → Mar 2002 178.8 | 0.28% | 0.56% | — |
| Nov 2001 | Mar 2001 176.2 → Sep 2001 178.3 | 1.19% | 2.38% | — |
| May 2001 | Sep 2000 173.7 → Mar 2001 176.2 | 1.44% | 2.88% | — |
| Nov 2000 | Mar 2000 171.2 → Sep 2000 173.7 | 1.46% | 2.92% | — |
| May 2000 | Sep 1999 167.9 → Mar 2000 171.2 | 1.97% | 3.94% | — |
| Nov 1999 | Mar 1999 165 → Sep 1999 167.9 | 1.76% | 3.52% | — |
| May 1999 | Sep 1998 163.6 → Mar 1999 165 | 0.86% | 1.72% | — |
| Nov 1998 | Mar 1998 162.2 → Sep 1998 163.6 | 0.86% | 1.72% | — |
| Sep 1998 | Sep 1997 161.2 → Mar 1998 162.2 | 0.62% | 1.24% | — |
Sources: BLS CPI-U NSA via FRED (CPIAUCNS), TreasuryDirect's I-Bond rate formula and rate chart, the Nowflation Forecast. Projections, not promises. The COLA is set by the Social Security Administration with the September CPI; I-Bond rates by the Treasury for November 1 and May 1; tax-year amounts by the IRS in a revenue procedure each fall. The IRS indexes from statutory base-year amounts with cumulative factors and rounds once, so chaining from the published 2026 amounts can differ from the official 2027 figures by one rounding step ($25 / $50). Chained CPI-U initial values are revised. Not tax, benefits or investment advice. Every call is graded on the scoreboard after the announcement.
Nowflation projects a 4.08% variable (inflation) rate for the November 2026 reset — a 2.04% semiannual inflation rate, doubled. At the current fixed rate of 0.9% (set for May 1, 2026) the composite would be 5%; enter the fixed rate Treasury actually announces to get your composite.
Treasury takes the change in the not-seasonally-adjusted CPI-U from March 2026 (330.213, actual) to September 2026 (336.94, actual), rounded to 0.01%, as the semiannual rate; the variable rate is twice that. The composite is fixed + 2 × semiannual + fixed × semiannual.
November 1, 2026 (14 days from October 18, 2026); Treasury sets the new rates for May 1 and November 1; Nov 1, 2026 is a Sunday, so the announcement can post on the nearest business day, and the November 2026 rate applies to bonds bought Nov 2026–Apr 2027. The rate a new bond earns now, announced May 2026, is 4.26%: a 0.9% fixed rate plus the 3.34% variable rate.
Yes: recomputing every inflation reset since 1998 from the published CPI-U matches Treasury's announced rate in 13 of 13 checked resets to the basis point. Both index months (March 2026 and September 2026) have printed, so the inflation half of the November 2026 rate is no longer a projection; the fixed rate is Treasury's call on the announcement day.