31 CFR § 359.8 - How does interest accrue on Series I savings bonds?

---
identifier: "/us/cfr/t31/s359.8"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "31 CFR § 359.8 - How does interest accrue on Series I savings bonds?"
title_number: 31
title_name: "Money and Finance: Treasury"
section_number: "359.8"
section_name: "How does interest accrue on Series I savings bonds?"
chapter_name: "FISCAL SERVICE, DEPARTMENT OF THE TREASURY"
subchapter_number: "A"
subchapter_name: "BUREAU OF THE FISCAL SERVICE"
part_number: "359"
part_name: "OFFERING OF UNITED STATES SAVINGS BONDS, SERIES I"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "5 U.S.C. 301; 12 U.S.C. 391; 31 U.S.C. 3105."
regulatory_source: "67 FR 64278, Oct. 17, 2002, unless otherwise noted."
cfr_part: "359"
---


# 359.8 How does interest accrue on Series I savings bonds?

A bond accrues interest based on both a fixed rate of return and a semiannual inflation rate. A single, annual rate called the composite rate reflects the combined effects of the fixed rate and the semiannual inflation rate. For more information, see appendix B of part 359.