Social Security Uses a Flawed Inflation Formula for Retirees -- but Right Now, It Doesn't Matter Much

The average retiree's Social Security benefits have lost roughly 13.7% of their buying power since 2010, according to an analysis by The Senior Citizens League (TSCL). Why? Social Security cost-of-living adjustments (COLAs) aren't keeping up with inflation, even though that's exactly what they're supposed to do.

There's a simple explanation for this reality: Social Security uses a flawed inflation metric for calculating the annual COLA. But so far in 2026, this flaw hasn't hurt retirees much.

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The flaw and the fix

The Social Security Administration (SSA) calculates the annual COLA using the Consumer Price Index for Urban Wage Earners and Clerical Workers (CPI-W). Specifically, SSA compares the CPI-W for the third quarter of the current year with the CPI-W for the same period in the previous year. The percentage difference, if any, is rounded to the nearest one-tenth of 1% to obtain the COLA.

That wouldn't be a bad approach, except for one glaring issue: the CPI-W isn't designed to reflect the prices of products and services purchased by seniors. For example, healthcare in retirement is one of the biggest expenses in older Americans' budgets, but it receives a much lower weight in the CPI-W than it should.

There is a fix to this flaw. Another inflation metric -- the Consumer Price Index for the Elderly (CPI-E) -- is specifically designed to track the purchasing behavior of older individuals. The weighting differences between the CPI-E and the CPI-W are striking. For example, healthcare costs make up around 11.3% of the CPI-E versus only 6.9% for the CPI-W.

Why hasn't Social Security replaced the CPI-W with the CPI-E? It requires an act of Congress. Several attempts have been made to address the COLA calculation, but none have succeeded so far.

Why 2026 is an exception

In most years, the CPI-E year-over-year increase is well above the increase for the CPI-W. However, 2026 is an exception.

In the June inflation report released by the U.S. Bureau of Labor Statistics (BLS), the CPI-W increased by 3.5% over the previous 12 months. The CPI-E rose by 3.6%, only slightly above the 3.5% rate. In May, the CPI-W increased by 4.4%, compared with the CPI-E's 4.2%.

Social Security's inflation metric flaw isn't as problematic this year. Why? It's primarily because the Iran war is the key factor driving higher prices. Oil and gas prices have risen sharply. Energy is one area where working-age Americans and retirees feel the pain from rising prices relatively equally.

If we look back before the Iran war began, the gap between the two inflation metrics is greater. For example, in January 2026, the CPI-W increased 2.2% year over year, well below the 2.6% increase for the CPI-E.

A silver lining that won't last

TSCL projects that the 2027 Social Security COLA will be 3.8%, one of the highest increases in recent history. The good news for retirees is that the adjustment wouldn't be much different if the CPI-E were used instead of the CPI-W.

However, the bad news is that this is a silver lining that almost certainly won't last. The inherent flaw in the CPI-W could rear its head sooner rather than later. If the conflict between the U.S. and Iran ends peacefully, oil and gas prices will decline significantly. The differences in the weightings of the CPI-W and the CPI-E would have a greater impact under this scenario.

The bottom line is that retirees are benefiting this year from a geopolitical event that is driving inflation higher, affecting both retirees and younger workers roughly equally. That won't always be the case. Until the CPI-W is replaced by an inflation metric that better reflects the costs seniors incur, the structural flaw in how the Social Security COLA is calculated will remain problematic.

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