2027 Social Security COLA: Q3 CPI-W Sets the January Benefit Jump

The 2027 Social Security cost-of-living adjustment will be determined by the third-quarter CPI-W data (July–September) and announced by SSA in mid-October 2026; the change is the percentage difference between this year's July–September CPI-W average and the same period a year earlier. Once confirmed, retirement benefits rise in January 2027, while SSI payments increase with the December 31, 2026 payment date; forecasts can shift as new inflation data arrives, so rely on the SSA figure rather than forecasts, since critics say CPI-W may not precisely reflect seniors' spending.