The 2027 Social Security cost-of-living adjustment is still not official, but the range has narrowed considerably now that two of the three inflation readings used in the calculation are available.
The Senior Citizens League now projects a 3.5% COLA for 2027, while AARP forecasts 3.6%. Both estimates are above the confirmed 2.8% COLA for 2026, but neither is an official Social Security Administration figure. Only September inflation data remains before the calculation can be completed.
The Bureau of Labor Statistics is scheduled to release the September 2026 Consumer Price Index on October 14 at 8:30 a.m. ET, according to the official BLS CPI release schedule. The final COLA can then be calculated using all three months of third-quarter CPI-W data.
Two of the three COLA months are now known
Social Security’s annual COLA is based on the Consumer Price Index for Urban Wage Earners and Clerical Workers, or CPI-W, which is produced by the Bureau of Labor Statistics. Readers who want a deeper explanation of the inflation indexes can review Investozora’s Consumer Price Index methodology guide.
Under the SSA’s official COLA formula, the agency compares the average CPI-W for July, August and September with the third-quarter average from the last year in which a COLA became effective. Any increase is rounded to the nearest one-tenth of 1%. For the upcoming calculation, the third-quarter 2025 CPI-W average is 317.265. The three readings that produced that average were:
- July 2025: 316.349
- August 2025: 317.306
- September 2025: 318.139
SSA publishes those figures in its official COLA computation table. BLS has now published two of the corresponding readings for 2026. The CPI-W reached 327.104 in July 2026, up 3.4% from a year earlier, according to the July CPI release from BLS.
It then increased to 328.481 in August, 3.5% above August 2025 and 0.4% higher than July on a not-seasonally-adjusted basis, according to the August CPI report. The average CPI-W for July and August 2026 therefore stands at about 327.793, compared with approximately 316.828 for the same two months in 2025.
That is an increase of about 3.46%, an Investozora calculation using the published BLS and SSA indexes: (327.793 − 316.828) ÷ 316.828 × 100 = approximately 3.46%. That is not the official 2027 COLA. September must still be included before the statutory three-month calculation can be completed.
Latest 2027 COLA forecasts have moved lower
The forecast picture has changed materially since this article was first published. The Senior Citizens League projected a 3.8% COLA in July, lowered its estimate to 3.6% in August, and on September 11 reduced its final pre-announcement forecast to 3.5% after the August CPI data became available.
TSCL said its September estimate was 0.1 percentage point below its August forecast and 0.7 percentage point above the 2.8% COLA for 2026. Its latest projection is available in the group’s September 11 COLA forecast.
AARP’s September 11 analysis projects a slightly higher 3.6% COLA. AARP said its estimate incorporates CPI-W information available through August along with an estimate for September inflation.
The current 3.5% to 3.6% forecast range is therefore substantially narrower than projections circulating earlier in the year. There is also less uncertainty now because July and August are no longer estimates. They are actual CPI-W observations. September is the only remaining month needed to complete the COLA calculation.
For historical context, Investozora’s Social Security COLA history tracks previous annual adjustments and how the current 2.8% increase compares with earlier years.
What a 3.5% or 3.6% COLA could mean for retirement benefits
SSA’s July 2026 Monthly Statistical Snapshot shows that the average retired worker received $2,085.98 per month. Using that amount only as an illustration:
- A 3.5% COLA would add approximately $73.01 per month, bringing the gross benefit to about $2,158.99.
- A 3.6% COLA would add approximately $75.10 per month, bringing the gross benefit to about $2,161.08.
Those figures are Investozora calculations, not benefit amounts published or guaranteed by SSA. Individual increases would depend on each beneficiary’s actual Social Security benefit before the adjustment is applied.
Medicare could reduce the increase some beneficiaries actually see
A higher gross Social Security benefit does not necessarily translate into an equally large increase in the amount deposited into a beneficiary’s bank account. The standard Medicare Part B premium is $202.90 per month in 2026, up from $185 in 2025, according to the 2026 Medicare Trustees Report.
The same Trustees Report estimates a $209.50 monthly Part B premium for 2027. That $209.50 figure is an estimate, not the final 2027 premium. Medicare Part B financing rates for 2027 have not yet been formally established, meaning beneficiaries should not treat the Trustees’ projection as the amount that will necessarily be deducted from their checks next year.
The distinction matters because beneficiaries who have Medicare premiums deducted from Social Security may see a smaller increase in their net payment than the increase in their gross Social Security benefit.
What happens next
September CPI-W is now the critical remaining number. BLS will release the September Consumer Price Index on October 14, 2026, at 8:30 a.m. ET, according to its official release calendar.
Once that report is published, the July, August and September 2026 CPI-W readings can be averaged and compared with the 317.265 third-quarter 2025 average under Social Security’s COLA formula. Until that happens, 3.5% and 3.6% remain forecasts, not the official 2027 Social Security COLA.
Under SSA’s current framework, the confirmed adjustment will apply to Social Security benefits beginning with December 2026 benefits payable in January 2027. Federal SSI payment levels are also adjusted through the COLA process. The SSA’s official COLA page remains the authoritative source for the final government figure.
Methodology: Investozora reviewed the Bureau of Labor Statistics’ July and August 2026 CPI releases, the BLS release calendar, SSA’s statutory COLA methodology and third-quarter 2025 CPI-W data, SSA’s July 2026 Monthly Statistical Snapshot, the Senior Citizens League’s September 11 forecast, AARP’s September 11 forecast and the 2026 Medicare Trustees Report. Dollar examples and the July-August CPI-W comparison are Investozora calculations based on verified government data and should not be interpreted as official SSA benefit determinations.
Last Updated: Saturday, September 19, 2026
