Quick answer: The 2027 Social Security COLA is not official yet. The calculation uses the average CPI-W reading for July, August, and September 2026. The first two official readings are 327.104 for July and 328.481 for August; the September figure is still pending. The Bureau of Labor Statistics (BLS) is scheduled to release September CPI data on October 14, 2026.
Google Trends showed a sharp rise in searches for “social security inflation adjustment 2027.” The useful answer is not a confident headline estimate: it is the formula, the known data, and the one number still missing.
2027 Social Security COLA: what is known now
- July 2026 CPI-W: 327.104.
- August 2026 CPI-W: 328.481.
- 2025 third-quarter CPI-W average: 317.265, the comparison base under the current formula.
- Missing input: September 2026 CPI-W.
- Official status: the Social Security Administration has not announced the 2027 COLA.
The Social Security Administration says it calculates a COLA from the percentage increase in the third-quarter average of the Consumer Price Index for Urban Wage Earners and Clerical Workers (CPI-W), then rounds the result to the nearest one-tenth of a percent. That makes the September CPI-W release decisive.
Why August inflation did not make the 2027 COLA final
BLS reported that CPI-W rose to 328.481 in August, up 0.4% from July before seasonal adjustment and 3.5% year over year. That is an important second data point, but the statutory calculation is based on a three-month average—not August alone and not headline CPI-U.
In other words: a 2027 COLA percentage circulating before the September CPI-W reading is a scenario or estimate, not an SSA determination.
The exact formula
Using the official values available as of September 13, 2026:
2027 COLA = [((327.104 + 328.481 + September CPI-W) ÷ 3 ÷ 317.265) − 1] × 100, rounded to the nearest 0.1%
The 317.265 figure is the official third-quarter 2025 CPI-W average. The calculation below is MGI EDIT’s arithmetic using the SSA formula; it is not a forecast.
What different September CPI-W readings would mean
| Illustrative September CPI-W | 2026 Q3 average | Mechanical COLA result | Change on a $2,000 gross monthly benefit |
|---|---|---|---|
| 327.000 | 327.528 | 3.2% | +$64/month |
| 328.481 (unchanged from August) | 328.022 | 3.4% | +$68/month |
| 329.500 | 328.362 | 3.5% | +$70/month |
For the formula to round to 3.4%, September’s CPI-W would need to fall roughly between 328.095 and 329.046, using the published index values to three decimal places and SSA’s rounding rule. This range is a calculation, not a prediction of September inflation.
How to estimate your own gross benefit change
Multiply your current gross monthly Social Security benefit by the eventual COLA percentage. For example, if the final rate were 3.4%:
- $1,000 monthly benefit → about +$34 per month
- $1,500 monthly benefit → about +$51 per month
- $2,000 monthly benefit → about +$68 per month
- $2,500 monthly benefit → about +$85 per month
- $3,000 monthly benefit → about +$102 per month
Those are gross illustrations only. Medicare premiums, tax withholding, and other deductions can change the amount that reaches an individual bank account. Do not treat a pre-announcement estimate as a final household-budget number.
When will the 2027 COLA become official?
The BLS says its September 2026 CPI release is scheduled for October 14, 2026, at 8:30 a.m. Eastern Time. The Social Security Administration says it will announce the next COLA in October 2026. Once that announcement is published, the estimate should be replaced with the official percentage and payment guidance.
Why this matters beyond retirement planning
The COLA is a household-income adjustment tied to a specific wage-earner inflation measure. It should not be confused with an investing signal or a Federal Reserve forecast. Still, the underlying CPI data matter to the broader economy: August’s headline CPI-U rose 0.4% for the month and 3.4% over 12 months, while CPI-W rose 3.5% over 12 months. The difference between these measures is one reason a clear, source-led explanation is more useful than a generic “benefits are rising” headline.
What to watch next
- The BLS September CPI release on October 14.
- The SSA’s official 2027 COLA announcement in October.
- Your benefit notice and any deduction changes before relying on a net-payment estimate.
Related MGI EDIT reading
Sources and methodology
- Social Security Administration: latest COLA calculation and third-quarter CPI-W base
- Social Security Administration: 2026 COLA announcement timing
- BLS: July 2026 CPI release
- BLS: August 2026 CPI release and September release schedule
Editorial note: This article is educational and does not provide individualized financial, tax, Medicare, or benefits advice. Updated September 13, 2026; figures will be reviewed when the next official releases are available.