Social Security checks will rise again in January, and with two of the three inflation readings already in, the size of the raise is nearly settled. Published forecasts run from 3.4% to 3.6% — the largest cost-of-living adjustment since 2023 and well above the 2.8% retirees received this year. The official number arrives on October 14, 2026, the morning the September inflation report comes out.
For the average retired worker, who received $2,087.52 in August, that is about $71 to $75 more a month. Part of it is already spoken for: Medicare's trustees project the standard Part B premium, which most retirees have taken straight out of their check, to rise by $6.60. This guide works out what is left, who keeps the least of it, and why a bigger raise can mean a bigger tax bill.
How it is calculatedThree months of one price index
The COLA is set by a formula in the Social Security Act, not by Congress or the SSA. It compares the average of one index — the Consumer Price Index for Urban Wage Earners and Clerical Workers, CPI-W — over July, August and September with the same three months a year earlier, and rounds the change to one decimal place.
(average CPI-W for Jul–Sep 2026 − 317.265) ÷ 317.265, rounded to 0.1%December 2026 benefit × (1 + COLA), paid from January 2027The base, 317.265, is the July–September 2025 average published by the SSA. July 2026 came in at 327.104 and August at 328.481, so the first two months are already running 3.32% above the base. Only September is missing — and it has to move a long way to change the result much.
Falls 0.3%
- Unrounded change
- 3.29%
- 2027 COLA
- 3.3%
Flat
- Unrounded change
- 3.39%
- 2027 COLA
- 3.4%
Rises 0.2%
- Unrounded change
- 3.46%
- 2027 COLA
- 3.5%
Rises 0.5%
- Unrounded change
- 3.56%
- 2027 COLA
- 3.6%
| September CPI-W vs August | Unrounded change | 2027 COLA |
|---|---|---|
| Falls 0.3% | 3.29% | 3.3% |
| Flat | 3.39% | 3.4% |
| Rises 0.2% | 3.46% | 3.5% |
| Rises 0.5% | 3.56% | 3.6% |
Source: CalculatorAI · calculatorai.app · BLS CPI-W; SSA COLA base 317.265
So a September reading anywhere between a 0.12% dip and a 0.17% rise gives 3.4%; a rise between 0.17% and 0.46% gives 3.5%; it takes a jump of almost half a percent in one month to reach 3.6%. The Committee for a Responsible Federal Budget estimates 3.4%, The Senior Citizens League 3.5% and AARP 3.6% — all three inside that band.
Your checkWhat 3.4%–3.6% adds in dollars
A COLA is a percentage, so it pays most to the people who already get the most. Applied to the SSA's August 2026 averages:
3.4%
- Raise a month
- $70.98
- New check
- $2,158.50
- After Part B
- $64.38
3.5%
- Raise a month
- $73.06
- New check
- $2,160.58
- After Part B
- $66.46
3.6%
- Raise a month
- $75.15
- New check
- $2,162.67
- After Part B
- $68.55
| COLA | Raise a month | New check | After Part B |
|---|---|---|---|
| 3.4% | $70.98 | $2,158.50 | $64.38 |
| 3.5% | $73.06 | $2,160.58 | $66.46 |
| 3.6% | $75.15 | $2,162.67 | $68.55 |
Source: CalculatorAI · calculatorai.app · SSA Monthly Statistical Snapshot, Aug 2026; 2026 Medicare Trustees Report
Over a year, a 3.5% COLA adds about $877 before Medicare and $798 after it to the average retired worker's income. Disabled workers, whose benefit averaged $1,635.90, get about $57 a month at 3.5%. To see your own figure, multiply your December benefit — shown in your my Social Security account and on the COLA notice the SSA usually posts there in early December — by the final percentage.
Medicare Part BThe part that comes straight back out
The standard Part B premium is $202.90 a month in 2026. The Medicare trustees' report, released on June 17, 2026, projects $209.50 for 2027 — a $6.60 increase. For most people on both programs the premium is deducted from the Social Security payment, so the increase is subtracted from the raise before any money arrives.
Because the premium rise is the same number of dollars for everyone, it takes a much bigger bite out of a small check:
Show these figures as a table
| Value (% of the raise) | |
|---|---|
| $1,000 benefit — $35.00 raise | 19 |
| $1,500 benefit | 13 |
| $2,088 (average) | 9 |
| $3,000 benefit | 6 |
| $4,000 benefit | 5 |
Source: CalculatorAI · calculatorai.app · drafts/social-security-cola-2027-numbers.mjs
TaxesA raise that can make more of your benefit taxable
Up to 85% of Social Security benefits can be subject to federal income tax, depending on combined income — your adjusted gross income plus tax-exempt interest plus half of your benefits. The thresholds have never been adjusted for inflation:
- Single filers — up to 50% of benefits taxable above $25,000 of combined income, up to 85% above $34,000.
- Married filing jointly — up to 50% above $32,000, up to 85% above $44,000.
The $25,000 line was set by the Social Security Amendments of 1983, and benefits were first taxed in 1984. In today's money, $25,000 in 1984 is about $77,500. Every COLA pushes a few more retirees across a line that was drawn for a much smaller number of them.
For a single retiree on the average benefit, a 3.5% COLA raises combined income by about $440. What that does to the taxable portion depends on the other income:
$10,000
- Taxable now
- $0
- Taxable after COLA
- $0
$15,000
- Taxable now
- $1,263
- Taxable after COLA
- $1,482
$25,000
- Taxable now
- $7,496
- Taxable after COLA
- $7,869
$40,000
- Taxable now
- $20,246
- Taxable after COLA
- $20,619
| Other income | Taxable now | Taxable after COLA |
|---|---|---|
| $10,000 | $0 | $0 |
| $15,000 | $1,263 | $1,482 |
| $25,000 | $7,496 | $7,869 |
| $40,000 | $20,246 | $20,619 |
Source: CalculatorAI · calculatorai.app · IRS Publication 915 worksheet method; drafts/social-security-cola-2027-numbers.mjs
Taxable does not mean taxed at that amount: the figures above are the portion of benefits that enters taxable income, where deductions still apply. From 2025 through 2028 people aged 65 and over can also claim an extra $6,000 senior deduction ($12,000 for a married couple who both qualify), which phases out above $75,000 of modified AGI for single filers and $150,000 for joint filers. For many retirees on the average benefit with modest other income, that deduction keeps the federal tax at or near zero; for retirees with IRA withdrawals or a pension in the $15,000–$40,000 range, the COLA makes $220 to $370 more of their benefit taxable.
Is it enough?The index retirees don't use
The COLA follows CPI-W, a price index built from the spending of working households. The Bureau of Labor Statistics also publishes an experimental index weighted to the spending of Americans aged 62 and older, the R-CPI-E, which gives more weight to housing and medical care. Advocates have argued for years that it would give retirees bigger raises. In the long run the data agrees, but only slightly — and this year it points the other way:
2024 COLA (set in 2023)
- CPI-W (used)
- 3.2%
- R-CPI-E
- 4.0%
2025 COLA (set in 2024)
- CPI-W (used)
- 2.5%
- R-CPI-E
- 3.0%
2026 COLA (set in 2025)
- CPI-W (used)
- 2.8%
- R-CPI-E
- 3.0%
2027 so far
- CPI-W (used)
- 3.32%
- R-CPI-E
- 3.22%
Q3 2006 → Q3 2025, total
- CPI-W (used)
- +59.4%
- R-CPI-E
- +61.6%
| Period | CPI-W (used) | R-CPI-E |
|---|---|---|
| 2024 COLA (set in 2023) | 3.2% | 4.0% |
| 2025 COLA (set in 2024) | 2.5% | 3.0% |
| 2026 COLA (set in 2025) | 2.8% | 3.0% |
| 2027 so far | 3.32% | 3.22% |
| Q3 2006 → Q3 2025, total | +59.4% | +61.6% |
Source: CalculatorAI · calculatorai.app · BLS CPI-W (CWUR0000SA0); BLS R-CPI-E research series, updated Sep 11, 2026
Over those nineteen years the elderly index rose faster in 13 of them, but the gap averaged less than a tenth of a percentage point a year. A $1,000 benefit indexed to CPI-W since 2006 would now be about $1,594; indexed to the R-CPI-E, about $1,616 — $23 a month more. In 2026 the elderly index is running below CPI-W, largely because its medical-care component was up only 1.6% over the year to August. The index is a research series, and switching to it would take an act of Congress.
The bigger gap is between what a COLA protects and what it doesn't. Social Security is indexed; most private pensions and annuities are not. At 3.4% inflation, a fixed $500-a-month pension buys what $358 buys today after ten years. Our Inflation Calculator shows that erosion for any amount, rate and number of years — and for the savings that fill the gap, the 4% withdrawal rule in how to maximize your 401(k) assumes you raise withdrawals by inflation each year, exactly as the COLA does.
What to doBefore and after October 14
Check your December benefit
Log in to your my Social Security account. The COLA applies to your December 2026 benefit, paid in January 2027, and the SSA usually posts your personal COLA notice in the account's message center in early December.
Budget with the net raise, not the gross
Subtract the Part B increase and any change to your Medicare Advantage or Part D premium. For a $1,500 check, a 3.5% raise is $52.50 gross and about $46 after the projected Part B increase.
Re-run your tax withholding
If you have federal tax withheld from benefits with Form W-4V, or pay estimated taxes, check whether the higher benefit pushes more of it into taxable income — especially with IRA withdrawals between $15,000 and $40,000.
Update your retirement plan
Enter the new monthly benefit in today's dollars in the Retirement Calculator, with your own inflation assumption, and see how much of your spending the savings still have to cover.
With rates rising again, cash that tops up a Social Security check is also worth a second look — the Fed's September hike works out what a quarter point means for savings accounts, and what dividend income actually requires shows how much capital it takes to add a few hundred dollars a month.
Frequently asked questions
When will the 2027 Social Security COLA be announced?
On October 14, 2026, the day the Bureau of Labor Statistics publishes the September Consumer Price Index at 8:30 a.m. Eastern. The SSA normally announces the COLA the same morning.
How much will Social Security go up in 2027?
Forecasts range from 3.4% to 3.6%. With July and August inflation data in, a flat September would produce 3.4%; a September rise of 0.17% or more would produce 3.5%.
When does the 2027 COLA show up in my check?
The increase applies to the December 2026 benefit, which is paid in January 2027. SSI recipients receive their increased January payment on December 31, 2026, because January 1 is a holiday.
Will the Medicare Part B premium take my whole raise?
Not in 2027 on current projections. The trustees project a $6.60 increase in the standard premium, which is less than a tenth of the average raise. A law known as the hold-harmless provision also stops the Part B increase from reducing most people's net Social Security payment below the previous year's.
Is Social Security taxable in 2027?
It can be. Up to 85% of benefits count as taxable income once combined income exceeds $25,000 for single filers or $32,000 for joint filers, and those limits are not adjusted for inflation. The $6,000 senior deduction for people 65 and over runs through the 2028 tax year.
Where these numbers come from
- COLA formula and base — SSA, "Latest Cost-of-Living Adjustment" (2026 COLA of 2.8%; third-quarter 2025 CPI-W average 317.265), checked September 29, 2026.
- CPI-W for July and August 2026 (327.104 and 328.481) and all earlier months — BLS public data API, series CWUR0000SA0, not seasonally adjusted. The September release date comes from the BLS release schedule.
- Elderly index — BLS R-CPI-E research series, all items and medical care, last updated September 11, 2026. October 2025 is missing from both indexes because of the 2025 lapse in appropriations; no calculation here uses it.
- Average benefits — SSA Monthly Statistical Snapshot, August 2026: 71.5 million beneficiaries, retired workers $2,087.52, disabled workers $1,635.90.
- Part B — $202.90 in 2026 (CMS); $209.50 projected for 2027 in the 2026 Medicare Trustees Report of June 17, 2026, as reported by MOAA.
- Forecasts — CRFB (3.4%), AARP (3.6%) and The Senior Citizens League (3.5%), as published in September 2026.
- Tax thresholds — SSA and IRS Publication 915; senior deduction — IRS guidance for tax years 2025–2028.
The scenario table rounds the unrounded change the same way the SSA does. Dollar figures apply a single COLA to the average benefit and ignore the rounding the SSA applies to each individual benefit (down to the nearest dime), so real checks will differ by cents. The tax table uses the standard worksheet for a single filer with no tax-exempt interest and does not compute the tax itself. The 1984-to-today comparison uses CPI-U annual averages (103.9 and 321.943). Every figure is reproduced in drafts/social-security-cola-2027-numbers.mjs. Educational information only, not tax or benefits advice.
