Two pieces of the three-month calculation that decides how much larger Social Security checks grow next year are now sitting in the government’s own data. The Bureau of Labor Statistics published the August inflation numbers on September 11, adding a second data point to a math problem that will not be finished until one more month of prices comes in. For the roughly 70 million people who collect Social Security or Supplemental Security Income, the answer to that math problem eventually becomes a real number added to a monthly check, so knowing where things stand before the final tally matters. Nothing about the 2027 raise is settled yet, but two of the three numbers behind it no longer have to be guessed at.
How the third quarter decides the raise
Social Security’s annual cost-of-living adjustment is not set by whatever the newest inflation report says. By law, the Social Security Administration compares the average Consumer Price Index for Urban Wage Earners and Clerical Workers, known as the CPI-W, across July, August and September of the current year against the same three-month average from the last year a raise was calculated. For the 2027 adjustment, that baseline third quarter of 2025 averaged 317.265 on the CPI-W index, a figure the SSA has already certified on its own site. The raise beneficiaries eventually see is the percentage difference between that fixed number and the 2026 third-quarter average, once all three months of 2026 exist. Because the formula compares whole quarters rather than single months, no monthly inflation report on its own can produce a finished figure, no matter how the number is framed in the days after it publishes.
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The two months now on the books
The first of the three numbers arrived in mid-August, when the government reported the July CPI-W at 327.104. The second landed on September 11, when the Bureau of Labor Statistics released its monthly Consumer Price Index report, numbered USDL-26-1496, putting the August index at 328.481, a level the agency says sits 3.5 percent above where the CPI-W stood twelve months earlier. Both figures come from the same monthly release the agency has published for decades, and both are now archived in the Social Security Administration’s own running table of monthly CPI-W values. Two of the three inputs the formula needs are, for the first time this year, matters of public record rather than estimates.
A different inflation number than the headlines
Most coverage of the August report focused on the Consumer Price Index for All Urban Consumers, the CPI-U, which the Bureau of Labor Statistics says rose 3.4 percent over the year. The CPI-W that drives Social Security’s raise is a separate index built from the spending of urban wage earners and clerical workers, and in the same release it came in slightly higher, at 3.5 percent over twelve months. The two indexes track similar categories of spending but weight them differently, which is one reason the number quoted in a general inflation headline is not automatically the number that ends up in Social Security’s formula.
Why the two-month average is not a forecast to bank on
Averaging the two published months gives 327.7925, a figure that sits 3.32 percent above the 317.265 base carried over from 2025. That arithmetic is accurate, but it describes two-thirds of a quarter, not the finished calculation Social Security actually uses. September’s CPI-W has not been collected into a published index yet, and a single additional month can pull the average up or down once it joins the other two. Presenting the two-month figure as this year’s raise would describe an unfinished sum as though it were the total, and it is also not how the agency itself will compute the number in October.
How this year’s pace compares
The Social Security Administration’s own historical table of quarterly CPI-W averages offers a useful yardstick. The adjustment that took effect this past January was built the same way, comparing a 308.729 third-quarter average from 2024 against 317.265 from 2025, a gain of roughly 2.8 percent. The year before that, the raise came from comparing 301.236 in the third quarter of 2023 to 308.729 in the third quarter of 2024, near 2.5 percent. Measured against that same 317.265 anchor, the two-month reading so far for 2026 is running a bit hotter than either of those two prior increases, though a single missing month is enough to move a percentage that will already be rounded to the nearest tenth of a point once it is final.
When the real number arrives
The Bureau of Labor Statistics has already scheduled the release carrying the missing piece: September’s CPI-W will publish as part of the next Consumer Price Index news release on October 14. That date lines up with when the Social Security Administration has historically announced the following year’s cost-of-living adjustment, since the agency needs the completed third-quarter average before it can finish the same comparison that produced the 317.265 base. Once the percentage is set, it becomes the raise applied to benefits paid starting in January, and notices explaining each beneficiary’s updated payment typically follow before that first adjusted check arrives.
Benefit programs that run on applications, not formulas
The cost-of-living adjustment is one of the few parts of a fixed income that moves on its own, worked out from published index numbers without anyone filing a form. Most of the other programs built for people over 60 work the opposite way. Medicare Savings Programs that cover the Part B premium, SNAP for households at 60 and older, and LIHEAP energy assistance are all opt-in, with thresholds set state by state, and each leaves benefits unclaimed simply because no agency signs a household up automatically.
The Benefits Checklist is a 63-page guide to 11 of those programs, with the 2026 income limits for each and a 50-state directory of the offices that handle them.
Compare the 11 programs and their 2026 income limits in The Benefits Checklist.
This article was produced with AI assistance and reviewed by a human editor. Figures are linked to their primary sources; where a claim could not be verified from the public record, we say so.
