Seventy-one million Social Security beneficiaries will learn their 2027 raise on Oct. 14, when the Bureau of Labor Statistics publishes September inflation data and the Social Security Administration applies the statutory formula. For now, advocacy groups and AARP are converging on a mid-3% adjustment—materially larger than the 2.8% increase that took effect in January 2026.

How the math locks on one morning

Congress tied COLAs to the Consumer Price Index for Urban Wage Earners and Clerical Workers. The Administration compares the average CPI-W for July, August and September 2026 with the same quarter a year earlier; the percentage change becomes the COLA, rounded to one decimal. Recording Law’s public guide notes the legal deadline to publish the determination is 45 days after Sept. 30, but in practice the number follows the September CPI release when BLS is on schedule.

BLS has penciled Sept. 14’s report for 8:30 a.m. Eastern on Oct. 14. Once the index is public, analysts will plug the final quarter average into spreadsheets that have been running all summer. There is no White House discretion in the percentage—only timing risk if data are delayed.

What 3.5% would buy

AARP’s September forecast calls for a 3.6% COLA in 2027, which the group says would add about $75 to the average retired worker’s monthly check. The Senior Citizens League and independent analyst Mary Johnson have published similar mid-3% estimates after August’s CPI print. All of those projections assume September does not deliver a violent downside surprise—something energy markets made less certain after late-summer fuel volatility.

Supplemental Security Income recipients see the new rate on Dec. 31 payments; mainstream Social Security checks reflect the increase starting in January 2027. Medicare Part B premiums, typically announced in the same season, can absorb part of the raise for beneficiaries who have premiums deducted from benefits, so net cash may be smaller than the headline percentage.

Politics around the number

Lawmakers do not vote on the annual COLA, but they do argue about solvency and tax thresholds that interact with benefits. Larger raises speed up trust-fund outflows unless Congress changes revenue or cost rules. That tension shows up in election-year rhetoric even when the COLA itself is automatic.

Some Republicans and Democrats have floated alternative inflation measures or one-time bonuses; none of those proposals are attached to the Oct. 14 release. Beneficiaries should plan on the CPI-W formula unless Congress acts later—a long shot in a lame-duck session focused on December appropriations.

What to do before Oct. 14

Create or refresh your my Social Security account to verify your earnings record and mailing preferences. If you manage a household budget, model both a 3.2% and 3.8% COLA to bracket grocery and heating costs; the final figure should land inside that band barring a September shock.

Taxpayers who work while collecting benefits should remember provisional-income thresholds do not adjust with COLA; a bigger check can push more income into the taxable range. And if you help parents or neighbors who are not online, mark Oct. 14 on the calendar—the announcement is the reference point for 2027 planning even though cash arrives in January.

How the raise compares with grocery bills

A mid-3% COLA lifts the average retired-worker benefit by less than $80 a month in AARP’s modeling, while grocery and utility costs in many regions moved faster than that in 2026. Advocacy groups use the gap to push for different inflation measures, but beneficiaries should plan on the CPI-W formula Congress enacted unless a bill actually passes.

State tax treatment varies: a dozen states still tax Social Security benefits for some income tiers, so a higher federal benefit can change state liability even when the federal portion is unchanged. Check your state revenue department’s 2027 brackets when they publish updates in November.

After the announcement

SSA will mail COLA notices in December. Compare the printed percentage with your own calculation using the July–September CPI-W averages once BLS posts the full tables. If the number looks wrong, call 1-800-772-1213 with your estimate in hand; clerical errors are rare but fixable before January deposits hit.