A US Savings Bond Pays 5.51%. What's Inside That Number
TreasuryDirect lists 5.51% for I bonds bought from 1 November 2026 to 30 April 2027: a fixed 1.40% for 30 years, the highest since 2006, plus an inflation part. The catch is a one-year lock and a $10,000 limit.
A US savings bond is paying 5.51% a year right now, and it comes straight from the US Treasury. It's the Series I savings bond, the I bond. TreasuryDirect lists that rate for I bonds bought from 1 November 2026 to 30 April 2027.
Two parts make the 5.51%
- A fixed rate of 1.40%. It is set the day you buy and stays for the life of the bond. TreasuryDirect's table shows nothing higher since November 2006, when it was also 1.40%. It was 0.00% through 2020 and 2021, and 0.90% in May 2026.
- An inflation rate of 2.04% for six months, set every 1 May and 1 November from changes in US consumer prices (CPI-U, food and energy included).
- Treasury's formula: fixed rate + (2 × semiannual inflation rate) + (fixed rate × semiannual inflation rate). That is 1.40 + 4.08 + 0.03, about 5.51%.
- The 5.51% holds for your first six months. After that the inflation part changes and the 1.40% stays.
The fixed rate never changes.
— TreasuryDirect, I bonds interest rates
The catch
- You can cash in an I bond only after 12 months.
- Cash it in before 5 years and you lose the last 3 months of interest. TreasuryDirect's example: cash it after 18 months and you get the first 15 months of interest.
- In a calendar year, one Social Security Number can buy up to $10,000 in electronic I bonds. So this is a US product.
If you're not in the US
- India: RBI's Floating Rate Savings Bonds, 2020 (Taxable) pay 8.05% from 1 July to 31 December 2026, set at the NSC rate (7.70%) plus 0.35% and reset every six months. The rate follows the NSC, not inflation, and the interest is taxable.
- UK: index-linked gilts pay coupons and repay principal "adjusted in line with the UK Retail Prices Index (RPI)", according to the Debt Management Office. They are bought through a stockbroker or bank.
- Compare any rate with your own country's inflation: 5.51% and 8.05% are paid in different currencies, against different price rises.
Before you lock money anywhere
Ask what part of the rate is fixed, and what you lose if you leave early. Those two answers matter more than the headline number. The exception is money you know you won't touch for years, where the lock costs you nothing.
Information, not investment advice. Rates as of 2 November 2026.
This is the long version of What Just Happened #05, a reel for @buildjayy on Instagram. Building a money app and want rates shown the honest way, fixed part and penalty included? Send me the word BUILD there, or start with the brief form on the front page.
Sources: TreasuryDirect, I bonds interest rates and I bonds; Reserve Bank of India, press release 2026-2027/587 (1 July 2026); UK Debt Management Office, About gilts. The scenes of Dana in the reel are AI video (Gemini).
- 5 Nov 2026
- Published, with the reel.
Product builder from Surat. Ships his own apps, runs live broadcasts, and takes on a few founders a year for product, brand and growth. hey@jaybutani.com