September CPI-W Rises 3.9%, Setting 2027 Social Security COLA at 3.6%

U.S. September inflation data finalized the 2027 Social Security cost-of-living adjustment at 3.6%, the fifth-largest increase in the past 35 years. The adjustment follows a 3.9% year-over-year rise in the CPI-W and a 3.7% increase in headline CPI-U. Beneficiaries will receive higher payments starting in January 2027, up 0.8 percentage points from the prior year's adjustment. The inflation rebound was largely driven by an energy cost surge, where overall energy prices jumped 20.4% year over year, including a 34.2% jump in gasoline and a 74.2% spike in fuel oil amid Middle East tensions.