Glossary entry
What Determines the 2027 Social Security COLA Estimate?
Last verified 2026-08-03
This is not financial or legal advice. Medicare/Medicaid and benefits rules vary by state and change over time — verify current rules with your state Medicaid office or Area Agency on Aging.
As of Aug. 3, 2026, the Social Security 2027 COLA estimate for retirees is still an estimate, not an official figure. The reason is not a secret negotiation or a political cliffhanger. The government is still missing part of the price data needed to do the calculation.
A Social Security COLA is a cost-of-living adjustment. It is meant to adjust benefits for inflation, not to reward work, age, need, or years on the program. Under the Social Security Administration’s rule, the annual COLA is based on the average Consumer Price Index for Urban Wage Earners and Clerical Workers, or CPI-W, for July, August, and September, compared with the average for those same three months one year earlier; the result is rounded to the nearest one-tenth of 1 percent.[1]
That one rule explains why forecasts can be useful and still not be final. Until July, August, and September CPI-W figures are all known, any 2027 number is a dated projection.
COLA means inflation adjustment, not a personal raise
The word “raise” is understandable in everyday conversation because a higher COLA can mean a higher monthly benefit. But the rule itself is not written around what a retiree needs next year, what rent did in a particular city, or whether prescription costs rose faster than groceries in one household.
The automatic COLA system began after the 1972 Social Security Amendments and has applied automatically since 1975.[1] It applies to Social Security beneficiaries and SSI beneficiaries; SSA’s latest COLA materials describe the adjustment as affecting more than 75 million people receiving Social Security and Supplemental Security Income.[2]
That broad reach is exactly why the wording matters. A forecast in a headline is not the same thing as the official COLA. The official COLA is the result of a published formula after the necessary inflation data is available.
The formula is a three-month comparison
The COLA calculation looks at one slice of the year: the third quarter. In plain English, SSA compares the average CPI-W for July, August, and September of the current measuring year with the average CPI-W for July, August, and September of the previous measuring year.[1]
For the 2026 COLA, SSA’s worked example used a third-quarter CPI-W average of 317.265 for 2025 and compared it with 308.729 for the third quarter of 2024. The increase was calculated this way: (317.265 − 308.729) ÷ 308.729 = 0.02765, which rounds to 2.8%.[2]
| Part of the calculation | 2026 SSA worked example |
|---|---|
| Average CPI-W for July–September 2025 | 317.265 |
| Average CPI-W for July–September 2024 | 308.729 |
| Difference | 8.536 |
| Difference divided by prior-year average | 0.02765 |
| Rounded COLA | 2.8% |
That example is worth more than a dozen guesses because it shows what must happen for 2027. The 2027 COLA needs the July, August, and September 2026 CPI-W average, then compares that average with the July, August, and September 2025 average. If September is not known yet, the final average is not known yet.
The rounding rule also matters. A calculation can move slightly as new CPI-W data arrives, and the final percentage is rounded to the nearest 0.1%. That is why a forecast can drift from one month to the next without anyone changing the law.
Why September is the missing piece for 2027
For the 2027 COLA, July 2026, August 2026, and September 2026 are the months that matter. Earlier inflation data can help forecasters make an educated projection, but it cannot complete the official formula.
That timing is why a 2027 estimate seen in June, July, or early August should be read with its date attached. A forecast made before the full third quarter is available is using known data plus assumptions, nowcasts, or trends. It may be careful work, but it is still not the official SSA number.
The reported date to watch is Oct. 14, 2026, when the Social Security Administration is expected to announce the official 2027 COLA after the September inflation data is available.[3]
Current 2027 estimates are clustered, but they are still projections
Once the formula is clear, the current forecast range becomes easier to read. As of early August 2026, three public estimates sit in the mid-3% range, but each one is a projection made before the official September data is complete.
| Forecaster or source | Reported 2027 COLA estimate | How to read it |
|---|---|---|
| The Senior Citizens League | 3.8% | Mid-2026 projection, subject to change |
| AARP | 3.6% | Advance forecast using available CPI-W data and nowcasts |
| Mary Johnson, reported by CNBC | 3.7% | July 2026 projection, subject to change |
The Senior Citizens League’s COLA Watch put the 2027 estimate at 3.8% in its mid-2026 update.[4] AARP published a 3.6% advance forecast, describing it as based on CPI-W data from October 2025 through June 2026 plus Cleveland Fed nowcasts.[5] CNBC reported Mary Johnson’s July 2026 estimate at 3.7%.[6]
The movement in the estimates is not a footnote; it is the warning label. The Senior Citizens League estimate moved from 2.8% in March 2026 to 3.9% in April and 3.8% from May onward.[4] Johnson’s estimate moved from 4.7% in June to 3.7% in July.[6] Those changes do not mean the forecasters were pretending to know the future. They show why a COLA estimate is a snapshot.
If you are trying to understand what those percentages might mean in dollars, use this companion explainer on what the 2027 Social Security COLA reduction really means. If your concern is how Medicare Part B premiums may affect the amount that actually lands in a monthly check, the Medicare net-check article is the better place for that question.
Recent COLA history shows why the number moves
COLAs have not followed a neat path because inflation has not followed a neat path. The 2026 COLA was 2.8%, after 2.5% for 2025 and 3.2% for 2024. The 2023 COLA was 8.7%, the largest in 40 years. Earlier history also includes zero-COLA years in 2010, 2011, and 2016, and a record 14.3% COLA in 1980.[1][2]
That history is useful mainly because it keeps the 2027 estimate in its proper box. A higher number generally means the measured CPI-W comparison rose more sharply. A lower number generally means it rose less. A zero COLA can occur when the comparison does not produce an increase under the rule.[1]
Where to verify the official 2027 COLA
There are three places to separate a forecast from the number that governs benefits.
- SSA’s official COLA pages on ssa.gov. These explain the formula and publish official COLA information.[1][2]
- The official SSA announcement, expected Oct. 14, 2026, after September CPI-W data is available.[3]
- Your personal my Social Security notice in November, which is where your individual benefit notice belongs.[3]
The first source tells you the rule. The announcement tells you the official percentage. The personal notice tells you how SSA applies the new amount to your own record. Those are different questions, and mixing them together is how many COLA headlines become more confusing than helpful.
If you help a parent, spouse, or neighbor sort benefit paperwork, it is reasonable to write the forecast down with the date beside it. For example: “AARP estimate, July 2026: 3.6%.” That small label keeps an estimate from being mistaken later for the official SSA figure.
What to remember before the official number arrives
The 2027 Social Security COLA is determined by a CPI-W formula, not by a headline. It compares the average CPI-W for July, August, and September 2026 with the average for those same months in 2025, then rounds the result to the nearest 0.1%.[1]
As of Aug. 3, 2026, the current public estimates near 3.6% to 3.8% are useful only if they are treated as dated projections. The official number belongs to SSA’s announcement after the third-quarter data is complete, and your individual benefit notice belongs in your my Social Security account in November.[3]
Last verified: Aug. 3, 2026. Reviewer: [site reviewer name], OTR/L, CAPS. This article is for general benefits-literacy information only and is not financial, tax, legal, or individualized Social Security advice. For official benefit information, use ssa.gov and your own my Social Security account.
References
- Cost-Of-Living Adjustment, Social Security Administration.
- Latest Cost-Of-Living Adjustment, Social Security Administration.
- Cost-of-living adjustment 2027 Social Security prediction announcement, Detroit Free Press / USA Today Network, July 31, 2026.
- COLA Watch, The Senior Citizens League, July 2026.
- Social Security COLA 2027 Increase Estimate, AARP, July 2026.
- Social Security COLA in 2027: Cooling inflation lowers estimate, CNBC, July 14, 2026.
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