{
  "name": "Series I savings bond fixed, semiannual inflation and new-issue composite rates",
  "dataThrough": "2026-05-01",
  "verifiedAt": "2026-08-30",
  "license": "https://pennycalc.com/data-license/1.0/",
  "methodology": "PennyCalc preserves Treasury-published fixed and semiannual inflation components and calculates the annualized new-issue composite rate using the formula in 31 CFR Part 359.",
  "limitations": [
    "The composite rate applies to a newly issued bond for its first six months. An older bond keeps its original fixed rate.",
    "The rate history does not forecast future semiannual inflation components.",
    "TreasuryDirect remains authoritative for an individual electronic bond balance."
  ],
  "sources": {
    "rateTable": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/",
    "historicalWorkbook": "https://www.treasurydirect.gov/files/savings-bonds/series-i-ussb-interest-rate-history.xlsx",
    "regulation": "https://www.ecfr.gov/current/title-31/subtitle-B/chapter-II/subchapter-A/part-359"
  },
  "rates": [
    {
      "rateSet": "1998-09-01",
      "issueStart": "1998-09",
      "issueEnd": "1998-10",
      "fixedRate": 3.4,
      "inflationRate": 0.62,
      "newIssueCompositeRate": 4.66,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "1998-11-01",
      "issueStart": "1998-11",
      "issueEnd": "1999-04",
      "fixedRate": 3.3,
      "inflationRate": 0.86,
      "newIssueCompositeRate": 5.05,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "1999-05-01",
      "issueStart": "1999-05",
      "issueEnd": "1999-10",
      "fixedRate": 3.3,
      "inflationRate": 0.86,
      "newIssueCompositeRate": 5.05,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "1999-11-01",
      "issueStart": "1999-11",
      "issueEnd": "2000-04",
      "fixedRate": 3.4,
      "inflationRate": 1.76,
      "newIssueCompositeRate": 6.98,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2000-05-01",
      "issueStart": "2000-05",
      "issueEnd": "2000-10",
      "fixedRate": 3.6,
      "inflationRate": 1.91,
      "newIssueCompositeRate": 7.49,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2000-11-01",
      "issueStart": "2000-11",
      "issueEnd": "2001-04",
      "fixedRate": 3.4,
      "inflationRate": 1.52,
      "newIssueCompositeRate": 6.49,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2001-05-01",
      "issueStart": "2001-05",
      "issueEnd": "2001-10",
      "fixedRate": 3,
      "inflationRate": 1.44,
      "newIssueCompositeRate": 5.92,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2001-11-01",
      "issueStart": "2001-11",
      "issueEnd": "2002-04",
      "fixedRate": 2,
      "inflationRate": 1.19,
      "newIssueCompositeRate": 4.4,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2002-05-01",
      "issueStart": "2002-05",
      "issueEnd": "2002-10",
      "fixedRate": 2,
      "inflationRate": 0.28,
      "newIssueCompositeRate": 2.57,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2002-11-01",
      "issueStart": "2002-11",
      "issueEnd": "2003-04",
      "fixedRate": 1.6,
      "inflationRate": 1.23,
      "newIssueCompositeRate": 4.08,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2003-05-01",
      "issueStart": "2003-05",
      "issueEnd": "2003-10",
      "fixedRate": 1.1,
      "inflationRate": 1.77,
      "newIssueCompositeRate": 4.66,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2003-11-01",
      "issueStart": "2003-11",
      "issueEnd": "2004-04",
      "fixedRate": 1.1,
      "inflationRate": 0.54,
      "newIssueCompositeRate": 2.19,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2004-05-01",
      "issueStart": "2004-05",
      "issueEnd": "2004-10",
      "fixedRate": 1,
      "inflationRate": 1.19,
      "newIssueCompositeRate": 3.39,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2004-11-01",
      "issueStart": "2004-11",
      "issueEnd": "2005-04",
      "fixedRate": 1,
      "inflationRate": 1.33,
      "newIssueCompositeRate": 3.67,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2005-05-01",
      "issueStart": "2005-05",
      "issueEnd": "2005-10",
      "fixedRate": 1.2,
      "inflationRate": 1.79,
      "newIssueCompositeRate": 4.8,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2005-11-01",
      "issueStart": "2005-11",
      "issueEnd": "2006-04",
      "fixedRate": 1,
      "inflationRate": 2.85,
      "newIssueCompositeRate": 6.73,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2006-05-01",
      "issueStart": "2006-05",
      "issueEnd": "2006-10",
      "fixedRate": 1.4,
      "inflationRate": 0.5,
      "newIssueCompositeRate": 2.41,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2006-11-01",
      "issueStart": "2006-11",
      "issueEnd": "2007-04",
      "fixedRate": 1.4,
      "inflationRate": 1.55,
      "newIssueCompositeRate": 4.52,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2007-05-01",
      "issueStart": "2007-05",
      "issueEnd": "2007-10",
      "fixedRate": 1.3,
      "inflationRate": 1.21,
      "newIssueCompositeRate": 3.74,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2007-11-01",
      "issueStart": "2007-11",
      "issueEnd": "2008-04",
      "fixedRate": 1.2,
      "inflationRate": 1.53,
      "newIssueCompositeRate": 4.28,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2008-05-01",
      "issueStart": "2008-05",
      "issueEnd": "2008-10",
      "fixedRate": 0,
      "inflationRate": 2.42,
      "newIssueCompositeRate": 4.84,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2008-11-01",
      "issueStart": "2008-11",
      "issueEnd": "2009-04",
      "fixedRate": 0.7,
      "inflationRate": 2.46,
      "newIssueCompositeRate": 5.64,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2009-05-01",
      "issueStart": "2009-05",
      "issueEnd": "2009-10",
      "fixedRate": 0.1,
      "inflationRate": -2.78,
      "newIssueCompositeRate": 0,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2009-11-01",
      "issueStart": "2009-11",
      "issueEnd": "2010-04",
      "fixedRate": 0.3,
      "inflationRate": 1.53,
      "newIssueCompositeRate": 3.36,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2010-05-01",
      "issueStart": "2010-05",
      "issueEnd": "2010-10",
      "fixedRate": 0.2,
      "inflationRate": 0.77,
      "newIssueCompositeRate": 1.74,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2010-11-01",
      "issueStart": "2010-11",
      "issueEnd": "2011-04",
      "fixedRate": 0,
      "inflationRate": 0.37,
      "newIssueCompositeRate": 0.74,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2011-05-01",
      "issueStart": "2011-05",
      "issueEnd": "2011-10",
      "fixedRate": 0,
      "inflationRate": 2.3,
      "newIssueCompositeRate": 4.6,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2011-11-01",
      "issueStart": "2011-11",
      "issueEnd": "2012-04",
      "fixedRate": 0,
      "inflationRate": 1.53,
      "newIssueCompositeRate": 3.06,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2012-05-01",
      "issueStart": "2012-05",
      "issueEnd": "2012-10",
      "fixedRate": 0,
      "inflationRate": 1.1,
      "newIssueCompositeRate": 2.2,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2012-11-01",
      "issueStart": "2012-11",
      "issueEnd": "2013-04",
      "fixedRate": 0,
      "inflationRate": 0.88,
      "newIssueCompositeRate": 1.76,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2013-05-01",
      "issueStart": "2013-05",
      "issueEnd": "2013-10",
      "fixedRate": 0,
      "inflationRate": 0.59,
      "newIssueCompositeRate": 1.18,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2013-11-01",
      "issueStart": "2013-11",
      "issueEnd": "2014-04",
      "fixedRate": 0.2,
      "inflationRate": 0.59,
      "newIssueCompositeRate": 1.38,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2014-05-01",
      "issueStart": "2014-05",
      "issueEnd": "2014-10",
      "fixedRate": 0.1,
      "inflationRate": 0.92,
      "newIssueCompositeRate": 1.94,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2014-11-01",
      "issueStart": "2014-11",
      "issueEnd": "2015-04",
      "fixedRate": 0,
      "inflationRate": 0.74,
      "newIssueCompositeRate": 1.48,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2015-05-01",
      "issueStart": "2015-05",
      "issueEnd": "2015-10",
      "fixedRate": 0,
      "inflationRate": -0.8,
      "newIssueCompositeRate": 0,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2015-11-01",
      "issueStart": "2015-11",
      "issueEnd": "2016-04",
      "fixedRate": 0.1,
      "inflationRate": 0.77,
      "newIssueCompositeRate": 1.64,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2016-05-01",
      "issueStart": "2016-05",
      "issueEnd": "2016-10",
      "fixedRate": 0.1,
      "inflationRate": 0.08,
      "newIssueCompositeRate": 0.26,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2016-11-01",
      "issueStart": "2016-11",
      "issueEnd": "2017-04",
      "fixedRate": 0,
      "inflationRate": 1.38,
      "newIssueCompositeRate": 2.76,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2017-05-01",
      "issueStart": "2017-05",
      "issueEnd": "2017-10",
      "fixedRate": 0,
      "inflationRate": 0.98,
      "newIssueCompositeRate": 1.96,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2017-11-01",
      "issueStart": "2017-11",
      "issueEnd": "2018-04",
      "fixedRate": 0.1,
      "inflationRate": 1.24,
      "newIssueCompositeRate": 2.58,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2018-05-01",
      "issueStart": "2018-05",
      "issueEnd": "2018-10",
      "fixedRate": 0.3,
      "inflationRate": 1.11,
      "newIssueCompositeRate": 2.52,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2018-11-01",
      "issueStart": "2018-11",
      "issueEnd": "2019-04",
      "fixedRate": 0.5,
      "inflationRate": 1.16,
      "newIssueCompositeRate": 2.83,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2019-05-01",
      "issueStart": "2019-05",
      "issueEnd": "2019-10",
      "fixedRate": 0.5,
      "inflationRate": 0.7,
      "newIssueCompositeRate": 1.9,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2019-11-01",
      "issueStart": "2019-11",
      "issueEnd": "2020-04",
      "fixedRate": 0.2,
      "inflationRate": 1.01,
      "newIssueCompositeRate": 2.22,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2020-05-01",
      "issueStart": "2020-05",
      "issueEnd": "2020-10",
      "fixedRate": 0,
      "inflationRate": 0.53,
      "newIssueCompositeRate": 1.06,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2020-11-01",
      "issueStart": "2020-11",
      "issueEnd": "2021-04",
      "fixedRate": 0,
      "inflationRate": 0.84,
      "newIssueCompositeRate": 1.68,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2021-05-01",
      "issueStart": "2021-05",
      "issueEnd": "2021-10",
      "fixedRate": 0,
      "inflationRate": 1.77,
      "newIssueCompositeRate": 3.54,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2021-11-01",
      "issueStart": "2021-11",
      "issueEnd": "2022-04",
      "fixedRate": 0,
      "inflationRate": 3.56,
      "newIssueCompositeRate": 7.12,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2022-05-01",
      "issueStart": "2022-05",
      "issueEnd": "2022-10",
      "fixedRate": 0,
      "inflationRate": 4.81,
      "newIssueCompositeRate": 9.62,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2022-11-01",
      "issueStart": "2022-11",
      "issueEnd": "2023-04",
      "fixedRate": 0.4,
      "inflationRate": 3.24,
      "newIssueCompositeRate": 6.89,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2023-05-01",
      "issueStart": "2023-05",
      "issueEnd": "2023-10",
      "fixedRate": 0.9,
      "inflationRate": 1.69,
      "newIssueCompositeRate": 4.3,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2023-11-01",
      "issueStart": "2023-11",
      "issueEnd": "2024-04",
      "fixedRate": 1.3,
      "inflationRate": 1.97,
      "newIssueCompositeRate": 5.27,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2024-05-01",
      "issueStart": "2024-05",
      "issueEnd": "2024-10",
      "fixedRate": 1.3,
      "inflationRate": 1.48,
      "newIssueCompositeRate": 4.28,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2024-11-01",
      "issueStart": "2024-11",
      "issueEnd": "2025-04",
      "fixedRate": 1.2,
      "inflationRate": 0.95,
      "newIssueCompositeRate": 3.11,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2025-05-01",
      "issueStart": "2025-05",
      "issueEnd": "2025-10",
      "fixedRate": 1.1,
      "inflationRate": 1.43,
      "newIssueCompositeRate": 3.98,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2025-11-01",
      "issueStart": "2025-11",
      "issueEnd": "2026-04",
      "fixedRate": 0.9,
      "inflationRate": 1.56,
      "newIssueCompositeRate": 4.03,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    },
    {
      "rateSet": "2026-05-01",
      "issueStart": "2026-05",
      "issueEnd": "2026-10",
      "fixedRate": 0.9,
      "inflationRate": 1.67,
      "newIssueCompositeRate": 4.26,
      "sourceUrl": "https://www.treasurydirect.gov/savings-bonds/i-bonds/i-bonds-interest-rates/"
    }
  ]
}