TIPS CPI updates
Each month's CPI-U print sets the TIPS reference CPI two and three months later. These pages record every print as it arrives, show the reference CPI values it fixes, and translate the change into what happens to inflation-adjusted principal. The series is CPI-U, all items, not seasonally adjusted, the index named in the TIPS terms.
Monthly prints
| Month | CPI-U (NSA) | Change | Reference CPI it sets |
|---|---|---|---|
| August 2026 | 334.980 | +0.32% | October 2026 daily and November 1, 2026 |
| July 2026 | 333.918 | -0.01% | September 2026 daily and October 1, 2026 |
| June 2026 | 333.952 | -0.35% | August 2026 daily and September 1, 2026 |
| May 2026 | 335.123 | +0.63% | July 2026 daily and August 1, 2026 |
| April 2026 | 333.020 | +0.85% | June 2026 daily and July 1, 2026 |
| March 2026 | 330.213 | +1.05% | May 2026 daily and June 1, 2026 |
The seasonal pattern
Because the series is not seasonally adjusted, some months fall in most years, often in the second half. A falling reference CPI lowers every TIPS index ratio for those dates, so principal and the next coupon shrink slightly, and a bond bought during such a stretch can show a small principal loss before the pattern reverses. The maturity floor guarantees only that the original principal is returned at maturity. How TIPS principal adjusts covers the floor and the interest calculation.
Sources: BLS series CUUR0000SA0 and TreasuryDirect TIPS and CPI data.
