how Social – Social Security cost-of-living adjustments are tied to third-quarter inflation data and announced each October. But the measure may miss how retirees actually spend—especially on medical care—and COLAs aren’t guaranteed every year, meaning income can stay flat
By the time many retirees notice the headlines about next year’s Social Security check, the calculation is already locked in. The Social Security Administration typically announces the COLA in October, but the numbers that drive it come from July through September.
That gap—between when retirees learn what their benefits will be and when the data was collected—is where the real stakes live. It determines whether a planned adjustment keeps pace with prices for the months that follow, and whether inflation could run ahead again before the next recalculation.
The first rule of the COLA is that it is built from third-quarter inflation data. specifically the Bureau of Labor Statistics’ Consumer Price Index for urban wage earners and clerical workers. or CPI-W. The COLA reflects the percentage increase in the average CPI-W for the third quarter (July through September) compared with the average CPI-W for the same quarter of the prior year.
Once those CPI-W figures are in, the Social Security Administration announces the COLA—usually in October. The process can create a painful timing problem: inflation doesn’t stop just because the COLA has been calculated.
If the third-quarter CPI-W numbers show the cost of living is up 3%, benefits will increase by 3%. But if inflation surges in October. November. and December after the COLA has been set. no additional adjustment is made to Social Security because the new inflation occurred after the calculation. If high inflation persisted throughout 2027, retirees could feel the squeeze long after the official increase.
The COLA is also not designed as a perfect match for senior spending. CPI-W tracks prices for urban wage earners and clerical workers. and those spending patterns don’t line up exactly with retirees’ household budgets. The result can be a systematic mismatch—one that matters most in categories where prices tend to rise fastest.
Health care is the clearest example. The formula can underestimate how much seniors spend on items such as medical care. since those areas often see more rapid price increases than other parts of the economy. The Senior Citizens League estimates that retirees lost around 20% of their buying power between 2010 and 2024 because of this issue.
That reality has a practical impact on retirement planning. Social Security may help offset inflation, but it may not protect purchasing power as fully as many retirees assume—especially later in retirement, when expenses like health care can carry more weight.
The final rule is that COLAs aren’t guaranteed every year. If inflation data shows prices stayed the same or declined, your Social Security benefit will not change. The benefit isn’t designed to move downward in those situations. though: if deflation occurs and prices start to go down. retirees won’t lose any benefits.
There have been years when seniors did not get a Social Security adjustment, including 2010, 2011, and 2016. While high inflation makes that outcome less likely right now, the possibility still exists. Retirees who live with fixed income have to plan for both directions—an adjustment that could be smaller than they expect. or no adjustment at all.
There is a counterintuitive side to that uncertainty. A year without a COLA can still be beneficial if inflation stays low. because retirement plans that don’t have automatic inflation protections won’t be pressured by rising prices. The point isn’t that a COLA missing is “good”—it’s that the cost of living. not the headline. is what ultimately determines how far money stretches.
The bottom line for retirees is to watch for the COLA news in October. because that’s when the change will be set for next year. But it’s also important to understand what the adjustment is—and what it isn’t. It’s not a raise in the way many people talk about raises at work. It’s an effort to help Social Security benefits hold their value when prices rise.
Social Security COLA cost-of-living adjustment CPI-W Bureau of Labor Statistics retirees inflation health care costs Senior Citizens League