What is Reopening Auction of US Treasury Bill?

Reopening Auction of US Treasury Bill (T-Bill) is a subsequent auction of a previously issued T-Bill.

When a shorter T-Bill shares the same maturity date as a longer T-Bill, the shorter T-Bill is considered as a reopening of the longer T-Bill. Bother T-Bills will have the same CUSIP number.

For example, the 26-week T-Bill 912797MV6 was reopened twice as a 13-week T-Bill and a 6-week T-Bill:

CUSIP: 912797MV6

Sep 26, 2024 - Original 26-week T-Bill announcement date 
Sep 30, 2024 - Original 26-week T-Bill auction date 
Oct 03, 2024 - Original 26-week T-Bill issue date
Dec 26, 2024 - 1st reopening 13-week T-Bill announcement date 
Dec 30, 2024 - 1st reopening 13-week T-Bill auction date 
Jan 02, 2025 - 1st reopening 13-week T-Bill issue date 
Feb 13, 2025 - 2nd reopening 6-week T-Bill announcement date 
Feb 18, 2025 - 2nd reopening 6-week T-Bill auction date 
Feb 20, 2025 - 2nd reopening 6-week T-Bill issue date 
Apr 03, 2025 - Maturity date 

⇒ Non-competitive Bidding of US Treasury Bill

⇐ Auction Result of US Treasury Bill

⇑ Introduction of US Treasury Bills

⇑⇑ US Treasury Securities