How Your Social Security Raise Is Calculated

One price index, three months of readings and a rounding rule decide the raise for more than 70 million people. Here is every raise since the formula took over, and how each one was worked out.

Each bar is one automatic cost-of-living adjustment, labelled the way the Social Security Administration labels them: by the year the raise took effect. From 1975 to 1982 that was June, paid in July. Since 1983 it has been December, paid in January, so the 2.8% bar for 2025 is the raise in 2026 payments. 1999 is shown at 2.5%: it was announced as 2.4%, then a Bureau of Labor Statistics software error came to light and Congress ordered it fixed. Source: Social Security Administration.

The formula, in one line

The raise is officially called the cost-of-living adjustment, or COLA. The rules for it sit in Section 215(i) of the Social Security Act, and once you strip out the legal language, the whole thing fits in one line:

The CPI-W is the Consumer Price Index for Urban Wage Earners and Clerical Workers. It is not the inflation number you hear on the news. That one is the CPI-U, which covers more than 90% of the population. The CPI-W covers about 30%: households that get more than half their income from clerical or wage jobs, with at least one earner working most of the year. More on why that matters below.

The law is specific about the averaging. The index for a quarter is "the arithmetical mean of such index for the 3 months in such quarter," and the increase is "rounded to the nearest one-tenth of 1 percent." Here is how that worked out for the raise in January 2026 payments:

Source: Social Security Administration, using Bureau of Labor Statistics CPI-W data.

317.265 divided by 308.729 is an increase of 2.765%. Rounded to the nearest tenth, that is 2.8%. Your base benefit amount is multiplied by 1.028 and rounded down to the dime, and the monthly payment is then rounded down to the whole dollar.

That is the entire calculation. Nobody adjusts it, nobody negotiates it, and the September CPI release is the last piece of data it needs. That is why the announcement lands the same day the September inflation numbers come out.

Only July, August and September count

The COLA is not the average inflation rate for the year. It is a comparison of two snapshots, each three months long, taken a year apart. Prices that go up at any point in between and stay up get caught by the second snapshot. But the timing can leave retirees waiting a long time.

Say grocery prices jump in October. That increase misses this year's snapshot, gets measured the following July through September, and finally shows up in benefits the January after that. That is about 15 months later.

2022 is the clearest example. Prices were rising faster than they had in 40 years, and retirees spent that year living on a 5.9% raise that had been measured in the summer of 2021. The 8.7% raise that caught up with 2022 did not show up in payments until January 2023.

It can also miss things entirely. If prices spike in the winter and fall back before July, the summer snapshot never sees it, even though retirees paid those higher prices for months.

The rule that kept the raise at zero two years running

The law says the COLA can never be negative. If prices fall, benefits stay where they are. That sounds simple, but there is a catch that most people never hear about: the comparison is against the last year a raise was actually triggered. In a normal year, that is last year. After a year with no raise, it is not.

Here is what that did after the 2008 financial crisis:

In 2010, prices had gone up over the previous year, and retirees still got nothing. They had to climb back past the 2008 level first.

The same thing happened on a smaller scale in 2015 and 2016. The third-quarter average fell in 2015, so there was no raise. In 2016 it was up 0.35% on the 2014 base, which produced the smallest automatic raise that wasn't a zero: 0.3%.

Worker prices, not retiree prices

Here is the part that gets argued about. The CPI-W tracks what working households buy. Retirees put a bigger share of their money into housing and health care, and over the long run those prices have tended to rise faster than the rest of the basket.

The Bureau of Labor Statistics does publish a research index for Americans 62 and older, called the CPI-E. It has data back to December 1982. The difference in what the two indexes weigh is big:

Source: Bureau of Labor Statistics. BLS calls the CPI-E a research index and says results should be treated as tentative, partly because its spending weights come from a relatively small sample of older households, and it prices the same stores and items as the regular CPI.

From December 1982 to December 2011, the CPI-E rose an average of 3.1% a year, against 2.9% for the CPI-W. That gap does not sound like much, but it compounds. It is not constant, either: from 2006 to 2011 the CPI-W actually rose slightly faster. Social Security's Chief Actuary estimates that switching the COLA to the CPI-E would add about 0.15 percentage points a year to the raise.

There are proposals on the other side as well. A chained version of the CPI-W, which assumes people switch to cheaper goods when prices rise, would run about 0.3 points a year lower than the CPI-W, according to Social Security's actuaries. Both ideas come up every time Congress talks about fixing the trust funds, because a small change to the COLA, compounded across tens of millions of people and decades of retirement, moves a lot of money.

Before 1975, Congress voted every raise

For the first 25 years of benefit increases, there was no formula. Congress passed a law every time, and the size of the raise was whatever the politics of the moment produced:

Month the increase took effect. Source: Social Security Administration.

The 20% raise in 1972 was the big one. It came in a bill Richard Nixon signed on July 1, 1972, four months before an election, and the same law set up automatic raises tied to inflation, later revised by Congress in 1973. The first automatic COLA was 8.0%, effective June 1975.

The system that actually ran from 1975 to 1982 compared first quarters and paid the raise every July. The 1983 rescue of Social Security changed that. It pushed the raise back six months to January, which saved money at a time when the trust fund was nearly empty. There was no raise in July 1983. The next one, 3.5%, showed up in January 1984. Starting with the raise after that, the measurement moved to the third quarter, and that schedule has been in place ever since.

What the raise does to a monthly payment

The headline percentage is not what lands in your bank account. Here is what the 2.8% raise did for the average retired worker in 2026:

Averages from the Social Security Administration's 2026 COLA fact sheet. Part B premiums from the Centers for Medicare and Medicaid Services. Most retirees have Part B taken directly out of their Social Security payment.

The Medicare increase ate about 32% of the average raise. For other groups the raise in dollars was smaller: about $44 for the average disabled worker, $52 for the average widow or widower, and $88 for the average retired couple.

There is one protection here, called the hold harmless rule. If the Part B increase is bigger than your Social Security raise, your premium increase is capped so your net payment does not go down. It covered about 70% of people on Part B in 2016, a year with no raise at all, when those people paid $104.90 a month for Part B while everyone else paid $121.80. With a 2.8% raise and a $17.90 premium increase, it only protects people with a benefit below roughly $640 a month, and many people with benefits that low have their premiums paid by Medicaid anyway. It also does not cover higher-income people who pay the Medicare surcharge, people whose premiums are paid by Medicaid, or new enrollees.

Then there is tax. The income thresholds that make Social Security benefits taxable, $25,000 for a single filer and $32,000 for a married couple, were set in 1983 and have never been adjusted for inflation. Every COLA, and every rise in other income, pushes a few more people over the line. The Congressional Budget Office estimates that slightly more than half of beneficiaries will owe income tax on part of their benefits in 2026.

A few other numbers move with the COLA. Supplemental Security Income rises by the same percentage, so the maximum federal payment for an individual went from $967 to $994 a month in 2026. The maximum earnings subject to Social Security tax ($184,500 in 2026) follows wage growth instead, but it is only allowed to go up in a year when a COLA is triggered. That is why it stayed at $118,500 in 2016, after the zero COLA in 2015.

The biggest and smallest raises

A benefit of $100 a month in May 1975, raised by every COLA since, would be about $640 a month today. That is the whole point of the formula: whatever else happens to the program, a retiree's benefit keeps roughly the same buying power for as long as they collect it, as measured by the CPI-W.

Sources: Social Security Administration, Cost-of-Living Adjustments history and Latest COLA pages; SSA 2026 COLA Fact Sheet; Social Security Act Section 215(i); SSA Office of the Chief Actuary; SSA, A Brief History of Social Security (benefit increases before 1975); Bureau of Labor Statistics, CPI-W data and research on the CPI-E; Centers for Medicare and Medicaid Services, 2026 Medicare Parts A and B premiums (Nov. 14, 2025); Congressional Research Service and Congressional Budget Office on taxation of Social Security benefits; Public Law 92-336 (1972) and Public Law 98-21 (1983).