Social Security recipients could receive a 2027 cost-of-living adjustment (COLA) of nearly 4%, driven by inflation climbing at its fastest pace in almost three years.

Seniors and others who receive Social Security benefits could see a COLA of 3.9% next year, according to a new estimate from the Senior Citizens League, an advocacy group for older Americans. 

"This is up quite a bit from earlier in the year, when our projection generally sat between 2% and 3%," Alex Moore, the statistician for the Senior Citizens League, told CBS News in an email.

As of January, the average retired worker received $2,071 in monthly Social Security benefits, according to the agency. A 3.9% boost would add $80.77 to the typical monthly check, raising it to about $2,152.

The COLA is meant to help benefits keep pace with inflation, but the calculation is backward-looking. Because the 2027 adjustment will be based on inflation from July through September, seniors may lose ground if prices rise sharply before or after that period.

Reflecting these challenges, older Americans have told the advocacy group they're struggling financially amid the recent spike in fuel prices caused by the Iran war, Moore added. Seniors received a 2026 COLA of 2.8%, but the Consumer Price Index rose at an annual rate of 3.8% in April and 3.3% in March. 

That means millions of Social Security recipients aren't keeping up with surging consumer prices. 

"As we go throughout the year, rising oil prices have the potential to worsen the situation," Moore said. "Higher energy prices make it more expensive to farm crops, transport goods and services, and even operate the machinery to produce goods in factories." 

Moore added, "So the inflation we're seeing from rising oil prices right now is likely just the tip of the iceberg, with downstream effects on inflation across the whole economy — and thereby seniors — yet to come."

The Senior Citizens League's estimate is roughly in line with a projection from the Committee for a Responsible Federal Budget, or CRFB, which on Tuesday forecast a COLA next year of 3.8%, based on today's inflation report. 

The nonpartisan group, which supports U.S. deficit reduction, added that the COLA could range from 3% to 4.5%, depending on the course of inflation over the next several months.

Social Security's financial issues

The Social Security COLA for 2027 will not be set until October, and the final figure could change depending on inflation's path over the rest of the year. 

A higher COLA could exacerbate the financial strains facing the Social Security Administration, which is grappling with a funding shortfall for its trust funds, the CRFB said on Tuesday. Paying out a higher COLA would mean drawing more deeply on the trust funds to pay benefits, according to the group. 

"We estimate it would worsen Social Security's shortfall by roughly $300 billion over the next decade and advance the insolvency of the old-age trust fund by three months from late 2032 to earlier in the year," the CRFB said. 

The group is urging lawmakers to shore up Social Security by capping benefits for wealthy retired couples at $100,000, which it said could save as much as $190 billion over a decade and close roughly 20% of the program's solvency gap.