Why Social Security Uses CPI-W for COLA
Why CPI-W is the legal COLA measure, how SSA compares third-quarter averages, and why one month cannot determine the result.
Published · Updated
CPI-W is the measure named for COLA
By law, the Consumer Price Index for Urban Wage Earners and Clerical Workers, or CPI-W, is the official measure SSA uses to calculate cost-of-living adjustments.
Official evidence Social Security Administration · as of 2026-08-31SSA compares two third-quarter averages
SSA compares the current-year third-quarter average for July, August, and September with the comparison third-quarter average from the last year a COLA was determined.
Official evidence Social Security Administration · as of 2026-08-31The 2027 comparison value is already known
For the 2027 calculation, the official 2025 third-quarter comparison average is 317.265.
Official evidence Social Security Administration · as of 2026-08-30Why one reading cannot settle the COLA
Because the current side of the comparison is a three-month average, one month is not enough to determine the official result. Use the 2027 COLA tracker for current-year estimate context and the COLA calculation guide for the formula.
Official evidence Social Security Administration · as of 2026-08-31General information only. Confirm personal benefit details with SSA or your my Social Security account.