Treasury bill rate history
Every 13-week bill auction since January 2024 from the Treasury Fiscal Data API, updated on each refresh.
High investment rate (coupon-equivalent yield) at each 13-week auction, Jan 2, 2024 to Oct 19, 2026 (147 auctions). Range: 3.622% (Jan 5, 2026) to 5.404% (Jan 2, 2024).
Latest 13-week auctions
| Auction | Investment rate | High discount rate | Bid-to-cover | Offering | Source |
|---|---|---|---|---|---|
| Oct 19, 2026 | 4.195% | 4.095% | 2.77 | $95B | TreasuryDirect auction results API (Fiscal Data not yet updated) |
| Oct 13, 2026 | 4.185% | 4.085% | 2.68 | $95B | Treasury Fiscal Data API |
| Oct 5, 2026 | 4.149% | 4.050% | 2.51 | $95B | Treasury Fiscal Data API |
| Sep 28, 2026 | 4.211% | 4.110% | 2.99 | $95B | Treasury Fiscal Data API |
| Sep 21, 2026 | 4.113% | 4.015% | 2.77 | $92B | Treasury Fiscal Data API |
| Sep 14, 2026 | 4.066% | 3.970% | 2.64 | $92B | Treasury Fiscal Data API |
| Sep 8, 2026 | 3.890% | 3.800% | 2.61 | $92B | Treasury Fiscal Data API |
| Aug 31, 2026 | 3.859% | 3.770% | 2.77 | $92B | Treasury Fiscal Data API |
| Aug 24, 2026 | 3.803% | 3.715% | 3.08 | $92B | Treasury Fiscal Data API |
| Aug 17, 2026 | 3.802% | 3.715% | 2.86 | $92B | Treasury Fiscal Data API |
| Aug 10, 2026 | 3.823% | 3.735% | 2.88 | $92B | Treasury Fiscal Data API |
| Aug 3, 2026 | 3.838% | 3.750% | 2.61 | $92B | Treasury Fiscal Data API |
Best after-state-tax option, reference states
Recorded on each refresh since Oct 21, 2026: top marginal state rate, before federal tax. Fund history starts with our first recorded run; we don't back-fill fund yields.
| Data as of | California | New York | Texas | Illinois | Florida |
|---|---|---|---|---|---|
| Oct 21, 2026 | 4.62% 52-wk T-bill | 4.62% 52-wk T-bill | 4.62% 52-wk T-bill | 4.62% 52-wk T-bill | 4.62% 52-wk T-bill |
Download the data
- bill_auctions.csv: every bill auction since 2024-01-01 (all terms, incl. cash management bills), from the Treasury Fiscal Data auctions dataset, with TreasuryDirect results filled in where Fiscal Data hadn't posted yet.
- snapshots.jsonl: one line per refresh (latest auction by term, each fund's yield and 2025 exempt share, after-tax figures for CA, NY, TX, IL and FL).
See how bill auctions work for what these fields mean.
Not financial advice. Rankings are mechanical calculations from published yields and issuer tax data. They ignore fees you pay your broker, trading spreads, minimums, liquidity, and your full tax picture. Check the source links before acting.