{"data":{"id":"us/31-cfr-359.11","jurisdiction":"us","citation":"31 CFR 359.11","heading":"What is the semiannual inflation rate?","body":"The index used to determine the semiannual inflation rate is the non-seasonally adjusted CPI-U (the Consumer Price Index for All Urban Consumers for the U.S. City Average for All Items, 1982-84 = 100) published by the Bureau of Labor Statistics of the U.S. Department of Labor. (For further information on CPI-U considerations, see appendix C to part 359 at section 1.) The semiannual inflation rate reflects the percentage change, if any, in the CPI-U over a six-month period. We announce this rate twice a year, in May and November. The semiannual inflation rate we announced in May 2002 reflects the percentage change between the CPI-U figures from the preceding March 2002 and September 2001. The rate of change over the six-month period, if any, will be expressed as a percentage, rounded to the nearest one-hundredth of one percent. More specifically, the semiannual inflation rate will be determined by the following formula (the resulting rate will be rounded to the nearest one-hundredth of one percent):\nSemiannual inflation rate = (CPI − UCurrent − CPI − UPrior) ÷ CPI −UPrior","path":["Title 31—Money and Finance: Treasury","Subtitle B—Regulations Relating to Money and Finance","CHAPTER II—FISCAL SERVICE, DEPARTMENT OF THE TREASURY","SUBCHAPTER A—BUREAU OF THE FISCAL SERVICE","PART 359—OFFERING OF UNITED STATES SAVINGS BONDS, SERIES I","Subpart A—General Information"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-31.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:25:25Z","sha256":"920b118ad02800bf8749d0aec4eeae5fb9fb3478d494b64bd56748404a8a8fc8","source_id":"us-cfr","stale":true,"prev":"us/31-cfr-359.10","next":"us/31-cfr-359.12"},"notice":"GroundRules: Original legal text. Not legal advice."}