What a Series I savings bond earns and is worth.
Covers: i bond, ibond, savings bond, series i, treasury, inflation bond, tips.
Open the Treasury I Bond tool →A Series I savings bond earns a composite rate that combines a fixed rate, set when you buy and locked for the life of the bond, with a semiannual inflation rate the Treasury resets every six months.
The composite (annualized) rate is fixed + (2 × the semiannual inflation rate) + (fixed × the semiannual inflation rate), floored at zero. We grow your purchase one six-month period at a time, applying half the composite rate each period, straight from the bundled TreasuryDirect rates.
This is a measured value through the last published rate period, never a forecast: we don't guess a future inflation rate. The headline is what cashing today would pay: an I bond can't be cashed in its first 12 months, and cashing before 5 years gives up the last 3 months of interest — half of the latest six-month period here. The interest is subject to federal income tax but exempt from state and local tax. Verify any figure on TreasuryDirect.
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