Social Security 2027 COLA Estimated at 3.5%, Medicare Part B to Absorb About 9% of Raise

The Senior Citizens League estimates the 2027 Social Security cost-of-living adjustment at approximately 3.5%, down from its August projection of 3.6%, which would be the largest increase in three years. A beneficiary receiving $2,000 monthly would gain about $70 before Medicare deductions, according to CNBC. The 2026 Medicare Trustees Report projects the 2027 standard Part B premium at $209.50, up $6.60, or roughly 3.25%, from $202.90. That leaves a $2,000 benefit with about $63.40 after the premium increase, meaning Part B absorbs approximately 9% of the raise. By comparison, the 2026 adjustment of 2.8% raised the average retired-worker benefit by $56, while Part B consumed about 32% of that increase. The final COLA depends on the September consumer price index reading for urban wage earners, scheduled for release on Oct. 14, 2026. Estimates differ: the Senior Citizens League and AARP cite 3.5% to 3.6%, while analyst Mary Johnson has published a lower figure.