Social Security COLA 2027: Formula and What You'll Keep

The 2027 COLA formula is nearly settled — only September's inflation reading can still move the number. Image: TechPulse USA

The Moment: Wednesday, 6 p.m. IST

The Social Security Administration announces the 2027 COLA on Wednesday, October 14, 2026, at 8:30 a.m. ET — 6:00 p.m. IST — minutes after the September inflation report lands. That reading is the last missing piece.

The Formula, in Plain English

Each year, the government averages the Consumer Price Index for Urban Wage Earners (CPI-W) — a cousin of headline inflation, weighted more toward gasoline, transportation, and food — across July, August, and September, and compares it to the same three months a year earlier. The percentage increase, rounded to the nearest tenth, becomes the COLA. If prices fell, the COLA is zero — last seen in 2009, 2010, and 2015.

Now the numbers that matter:

• The base (Q3 2025 average): 317.265 — from July 316.349, August 317.306, September 318.139.
• July 2026: 327.104 — up 3.4% from a year earlier.
• August 2026: 328.481 — up 3.5% from a year earlier.
• The July–August average: 327.793 — already 3.3% above last year's base, with September still to come.

That is why the band is so tight. Two of the three CPI-W inputs are already in — only September's reading can still move the needle. Rule of thumb: September CPI-W above 329.047 means a 3.5% COLA; flat with August means 3.4%.

The Forecasts Have Converged

Forecaster	2027 COLA estimate
The Senior Citizens League (final)	3.5%
AARP	3.5–3.6%
FEDweek	3.5%
Independent analyst Mary Johnson	3.4%

The likely range: 3.4–3.6%. For context, that beats 2026's 2.8% comfortably — and a 3.5% reading would be the biggest COLA since 2023.

Note: CPI-W ran +3.5% year-over-year through August versus +3.4% for headline CPI, because it weights gasoline and groceries more heavily — the point of using it for this calculation.

The Paycheck Math: What a 3.5% Raise Looks Like

Percentages do not pay bills; dollars do. At a 3.5% COLA:

Your current monthly benefit	Monthly raise	New monthly benefit
$1,500	+$52.50	$1,552.50
$1,940	+$67.90	$2,007.98
$2,000	+$70.00	$2,070.00
$2,083 (average retired worker)	+$72.91	$2,155.91

Published estimates agree: about $68 a month in several analyses, $67.90 in TSCL's own model, roughly $71 in this week's Morningstar/MarketWatch figures. Whichever number lands today, the order of magnitude is settled: the low-$70s per month, before Medicare.

What Medicare Takes Back

Here is the part most headlines skip. The raise arrives before the Medicare Part B premium is deducted — and that premium is projected to rise too.

The 2026 Medicare Trustees Report projects the standard Part B premium climbing from $202.90 to $209.50 a month — a $6.60 increase, the smallest rise since 2023. Subtract that from a ~$68–73 raise, and the average retiree actually keeps roughly $61–66 a month.

Caveat: the official Part B premium is not announced until mid-November, and the trustees' projections have missed before. Treat $209.50 as the best available estimate. (The long-standing "hold harmless" rule also prevents Part B increases from cutting most people's net check below the prior year's level.)

When the Money Arrives

The raise lands in January 2027 checks — SSI recipients see it at the end of December 2026. It applies automatically to retirement, survivor, disability (SSDI), and SSI benefits. Nothing to apply for, no form to file.

FAQ: The Questions Everyone Asks

When exactly is the 2027 COLA announced?
Wednesday, October 14, 2026, at 8:30 a.m. Eastern — 6:00 p.m. IST — right after the September CPI release.

How is the COLA calculated?
It is the percentage change in the average CPI-W for July–September 2026 versus July–September 2025, rounded to the nearest tenth of a percent.

Can the COLA ever go down?
No. If consumer prices fall over the measurement period, the COLA is simply zero — benefits never decrease. That happened in 2009, 2010, and 2015.

Does the COLA apply to SSDI and SSI too?
Yes. The same percentage applies to retirement, survivors, disability (SSDI), and Supplemental Security Income benefits.

Will I owe tax on the raise?
Possibly. Up to 85% of benefits can be taxable for higher earners, and the income thresholds have not moved since the 1990s — so each raise nudges more retirees over the line. Ask your tax preparer.

I claimed early / I get spousal benefits — do I still get the COLA?
Yes. The COLA applies to your actual benefit amount, whatever it is.

What Happens Next

This evening, the official number goes live here the moment it drops — with what it means for your benefit level. Then on Thursday, Medicare Open Enrollment begins (through December 7), with the Part D deductible jumping to $700 — the biggest hike ever. Circle that date too.

Sources: The Senior Citizens League; AARP; FEDweek; 2026 Medicare Trustees Report; Bureau of Labor Statistics CPI-W data; Morningstar/MarketWatch.

Published October 14, 2026 · By Daniel Rao, TechPulse USA