Why aren't Treasury bill auction reopenings marked as reopenings on the Treasury Auction Schedule?

External question — Personal Finance Stack Exchange Author: Franck Dernoncourt Original post: https://money.stackexchange.com/questions/155861 License: CC BY-SA 4.0 — https://creativecommons.org/licenses/by-sa/4.0/ Adaptation: HTML converted to plain text; contact email addresses removed. Let's consider on the 13-week bill whose auction date is Monday, March 13, 2023 on Treasury Tentative Auction Schedule . It's not marked as a reopening on the Treasury Tentative Auction Schedule (no R in the reopening column): However, on my broker's website, the 13-week bill seems to be a reopening, since it's actually a 52-week bill (CUSIP: 912796X53 ): Why aren't Treasury bill auction reopenings marked as reopenings on the Treasury Auction Schedule? I feel I may have misunderstood something.

External answer — Personal Finance Stack Exchange Author: littleadv Original post: https://money.stackexchange.com/a/155862 License: CC BY-SA 4.0 — https://creativecommons.org/licenses/by-sa/4.0/ Adaptation: HTML converted to plain text; contact email addresses removed. Treasury bills have no reopenings. See here : Note: Bills have no reopenings. Instead, when needed, we auction short-term Cash Management Bills. (See the page about Bills). Edit: your brokerage doesn't seem to say that this is a reopening, so I'm not sure why you even thought that. You cannot participate in the Treasury offering of CMBs, they're only open for institutional investors. By the time they hit the secondary market - they're indistinguishable from any other treasury with the same maturity date (hence the same CUSIP).

External answer — Personal Finance Stack Exchange Author: Morrison Chang Original post: https://money.stackexchange.com/a/155863 License: CC BY-SA 4.0 — https://creativecommons.org/licenses/by-sa/4.0/ Adaptation: HTML converted to plain text; contact email addresses removed. As linked to by @littleadv, Treasury Bills aren't reopened. From the Federal Registry July 28, 2004, Part IV, Department of the Treasury, Fiscal Service, 31 CFR Part 356 Sale and Issue of Marketable Book-Entry Treasury Bills, Notes, and Bonds—Plain Language Uniform Offering Circular; Final Rule https://www.govinfo.gov/content/pkg/FR-2004-07-28/pdf/04-17012.pdf § 356.5 What types of securities does the Treasury auction? We offer securities under this part exclusively in book-entry form and as direct obligations of the United States issued under Chapter 31 of Title 31 of the United States Code. The securities are subject to the terms and conditions in this part, the regulations governing book-entry Treasury bills, notes, and bonds (31 CFR Part 357), and the auction announcements. When we issue additional securities with the same CUSIP number as outstanding securities, we consider them to be the same securities as the outstanding securities. (a) Treasury bills. (1) Are issued at a discount; (2) Are redeemed at their par amount at maturity; and (3) Have maturities of not more than one year. ... So what is going on with the CUSIP? Checking the Treasury Direct site: https://www.treasurydirect.gov/auctions/auction-query/?cusip=912796X53 The CUSIP 912796X53 as of EOD 2023-03-13 has 3 Bills with the same maturity date: CUSIP Security Type Security Term Auction Date Issue Date Maturity Date Price per $100 912796X53 Bill 13-Week 03/13/2023 03/16/2023 06/15/2023 98.799306 912796X53 Bill 26-Week 12/12/2022 12/15/2022 06/15/2023 97.659278 912796X53 Bill 52-Week 06/14/2022 06/16/2022 06/15/2023 96.946444 As all Bills are issued at discount to par, it may be better to think of the CUSIP as marking the maturity date for all short term Treasury Bill/auction/non-auction obligations which are due on that date. Logically if you transacted on a $10,000 USD 52-week Bill maturing on 06/15/2023 at the same date/time as the auction for the 13-week Bill maturing on 06/15/2023, the par value of $10,000 USD doesn't change, only the price/discount value would change matching the 13-week Bill auction discount. The seller capturing the increase in price from the original 52-week Bill issue date.