October 14 is the day the 2027 COLA stops being a guess

Put October 14, 2026 on the calendar. That is when SSA is expected to publish the confirmed 2027 cost-of-living adjustment.

Everything before that date is arithmetic in progress.

Why the date is fixed by the formula

The COLA is not a decision anyone makes. It is a calculation set in law, using the CPI-W index for July, August and September. September’s reading is published in mid-October — and until it exists, the average cannot be computed.

That is the whole reason estimates keep moving. Each monthly inflation release replaces a guess with a fact, and the projection shifts. One estimate this year ran at 3.8%, then 3.6%, as inflation moderated.

What lands with it

The COLA announcement does not travel alone. Around the same window:

• CMS confirms the Medicare Part B premium (around November) — deducted from your check before you see it
• The IRS publishes inflation adjustments for the next tax year (October or November)
• SSA sets the taxable maximum and the earnings test thresholds for 2027

The number to run yourself

When the figure lands, multiply your current benefit by it. Then subtract the Part B increase, because that comes out first. The difference between those two is what actually changes in your deposit — and it is usually smaller than the headline percentage suggests.

Questions people ask