2027 Social Security COLA: What Is Known Before the October Announcement

The number is not out yet, and here is the exact date it will be

The 2027 Social Security cost-of-living adjustment will be announced on October 14, 2026. That is not a guess about a press release. The COLA is arithmetic on the September Consumer Price Index, and the Bureau of Labor Statistics publishes September 2026 CPI at 8:30 a.m. Eastern on October 14, 2026, per its published release calendar. The Social Security Administration puts out the COLA the same morning, because by then the number already exists.

Anything before that date is a projection. As of early September 2026, only July data is in. The Senior Citizens League, an advocacy group publishing a monthly estimate, projected 3.6% on August 12, 2026 from the July CPI-W reading. August CPI publishes September 11, 2026, and September CPI on October 14. Two of the three months that decide the 2027 COLA are still unpublished, so treat every 2027 figure circulating now as an estimate that can move.

For comparison, the 2026 COLA was 2.8%, and it started with benefits payable in January 2026. The SSA keeps the running history and the current announcement on its cost-of-living adjustment page.

How is the COLA actually calculated?

It is one subtraction. Social Security averages the CPI-W for July, August and September of the current year, averages the same three months from the last year a COLA was set, and takes the percentage increase. Round to the nearest tenth of a percent. That is the COLA.

Three things follow from that formula, and all three surprise people:

• Only three months count. Prices in January through June of 2026 do not directly set the 2027 COLA. They matter only insofar as they left the price level higher going into July.
• If the third-quarter average does not rise, there is no COLA. The law does not allow a negative adjustment. Benefits stay flat instead, which happened in 2010, 2011 and 2016.
• The index is CPI-W, not the CPI you see on the news. Headline inflation reporting usually quotes CPI-U. The two track closely but are not identical, and the COLA is set by CPI-W alone.

If you want to see what a given inflation rate does to a fixed dollar amount over several years, the inflation calculator will run it.

Why your real costs can outrun the index that sets your raise

CPI-W stands for Consumer Price Index for Urban Wage Earners and Clerical Workers. Read that literally, because it is literal. To be in the CPI-W reference population, a household must get more than half its income from clerical or wage occupations, and have at least one earner who worked at least 37 weeks in the prior year. That population is roughly 29% of the country, and by construction it is mostly people who are still working.

BLS explains the split between its two main indexes in its own comparison of CPI-W and CPI-U. The practical consequence for a retiree: the basket being priced is weighted toward a working household's spending. Gasoline and commuting costs carry more weight than they do in a retired household's budget. Medical care carries less. A retiree who drives 3,000 miles a year and spends heavily on prescriptions, dental work and Medicare supplements is having their benefit indexed to somebody else's shopping cart.

BLS also computes an experimental index for Americans 62 and older, the CPI-E, which weights medical care and shelter more heavily. It is not used to set the COLA. Using it would require an act of Congress, and proposals to switch have been introduced repeatedly without passing. Until the law changes, CPI-W is the index, whatever your own costs did.

When does the higher payment actually arrive?

The increase is effective with benefits payable for December 2026, and Social Security pays a month in arrears, so the first check with the 2027 COLA in it is your January 2027 payment. Nothing changes in your October, November or December 2026 deposits.

Two timing details people trip over:

The October announcement and the December notice are different things. In December, SSA posts a personalized COLA notice, showing your 2027 benefit and the Medicare premium coming out of it, to the message center of your my Social Security account. That notice describes the January payment. It is not a second increase.

SSI is on a different clock. SSI recipients get the same percentage, one month earlier in calendar terms, because SSI pays on the first of the month. January 1, 2027 falls on a Friday that is a federal holiday, and payments due on a holiday are issued the preceding business day. The January 2027 SSI payment lands on December 31, 2026. Two SSI payments arriving in December is a payment-date artifact, not a bonus.

Will Medicare take most of it?

Possibly. This is the single largest gap between the headline percentage and what actually hits the bank account.

If you are on Medicare, your Part B premium is deducted from your Social Security payment before it is deposited. The gross benefit and the net deposit are two different numbers, and the COLA applies to the first one. CMS set the 2026 standard Part B premium at $202.90 a month, with a $283 annual deductible, in its 2026 premiums and deductibles fact sheet. The 2027 premium is announced separately, usually in November 2026. The 2026 Medicare Trustees Report projected roughly $209.50 for 2027, but that is a projection, not the rate.

Here is the arithmetic on a hypothetical retiree, using a made-up 3% COLA purely to show the mechanism:

A $60 headline becomes $53 in the account. In a year with a small COLA and a large premium jump, the net can approach zero. How the premium is set and collected is covered in how Medicare premiums work.

The hold harmless provision is the floor under this. It caps the dollar increase in your Part B premium at the dollar increase in your Social Security benefit, so a premium hike cannot cut your net deposit below last year's. It protects you only if your Part B premium is deducted from your Social Security payment. It does not cover you if you are new to Medicare that year, if you pay an income-related surcharge, or if a state Medicaid program pays your premium. Note what hold harmless does and does not promise: it protects the deposit from shrinking. It does not promise you keep the raise.

What changes at the same time if you are still working

The October announcement is not only the COLA. SSA releases the other indexed figures the same day, and two of them hit people who are drawing benefits while working.

The taxable maximum is the wage ceiling for Social Security tax. It was $184,500 for 2026, up from $176,100. Earnings above it are free of the 6.2% Social Security portion, though the Medicare portion continues with no cap. The 2027 figure comes out October 14. See the 2026 wage base and how it works for the mechanics, and how FICA is split for where each piece goes.

The retirement earnings test withholds benefits if you claim before full retirement age and keep earning. For 2026, SSA withholds $1 of benefits for every $2 of earnings above $24,480 if you are under FRA all year, and $1 for every $3 above $65,160 in the year you reach FRA, counting only the months before your birthday month. Once you hit FRA there is no limit. Withheld benefits are not confiscated: your benefit is recomputed upward at FRA to credit them back. But the cash is gone in the meantime, which is what matters to a monthly budget.

A bigger benefit can mean a bigger tax bill

Up to 85% of Social Security benefits can be taxable, and the thresholds that decide it are not indexed to inflation. They have not moved since 1993. IRS Publication 915 sets out the test: add your other income plus half your benefits, and if the total tops $25,000 filing single or $32,000 filing jointly, up to 50% of benefits become taxable; above $34,000 and $44,000, up to 85%.

Because the thresholds are frozen and the benefit rises every year with the COLA, more retirees cross those lines each year without any real increase in purchasing power. That is a design feature of the 1983 and 1993 laws, not an accident.

One partial offset exists for now. A deduction of $6,000 per person age 65 or older applies for tax years 2025 through 2028, phasing out above $75,000 of modified AGI for single filers and $150,000 for joint filers. It reduces taxable income, it does not exempt benefits, and it expires after 2028 unless extended. It stacks on top of the ordinary standard deduction and the extra amount for age 65.

What people get wrong about the COLA

Budgeting on the headline instead of the deposit. The percentage applies to your gross benefit. Your deposit is gross minus Part B, minus any Part D or IRMAA surcharge, minus voluntary tax withholding. Take last December's deposit, not last December's benefit statement, and build next year's household budget from the number that actually arrives.

Calling it a raise. A raise increases what you can buy. A COLA tries to hold it steady. If your costs rose 3% and your benefit rose 3%, you did not gain anything, and the frozen tax thresholds mean you may have lost a little.

Still working and not checking the earnings test. People take a part-time job in January without checking the annual limit, then get a letter in the spring saying benefits are being withheld. The limit changes every year, and it is announced in the same October release as the COLA.

Forgetting that a higher benefit can trigger IRMAA. The income-related monthly adjustment amount is a cliff, not a phase-in: one dollar over a threshold moves you into a full bracket. For 2026, CMS set the first tier above $109,000 of modified AGI for single filers and $218,000 for joint filers. It is assessed on your tax return from two years earlier, so the 2027 surcharge looks at your 2025 income. A COLA that increases your taxable benefits, or a one-time event like a Roth conversion or a home sale, can push you over a line that shows up two years later.

What a COLA does not do

It does not repay lost ground. The COLA is set on last quarter's prices, and it applies to next year's checks. That lag is permanent. In a year when inflation spikes after September, you carry the higher prices for months before the adjustment lands, and nothing later makes up the gap.

It does not fix your personal inflation rate. If your costs are dominated by prescriptions, long-term care, homeowners insurance or property tax, and those rose faster than the CPI-W basket, the COLA closes part of the gap and no more.

It does not increase anyone's benefit relative to anyone else's. It is a uniform percentage, so the gap between a high and a low benefit widens in dollar terms every year.

It does not change your claiming decision, your full retirement age, or your spousal and survivor benefit rules. Those are separate laws. And it does not reach most private pensions, which often have no automatic adjustment at all, so only part of a retiree's income is indexed.

What to do between now and January

• Mark October 14, 2026 for the announcement, and note that the taxable maximum and earnings test limits are released the same day.
• Find your December 2026 deposit amount, not your benefit statement figure, and use that as the baseline for what changes in January.
• Watch for the CMS announcement of the 2027 Part B premium, expected in November 2026, and subtract it from the new gross benefit yourself.
• Check your my Social Security message center in December for the personalized COLA notice showing your 2027 amount.
• If you are working and under full retirement age, compare your expected 2027 earnings against the new earnings test limit as soon as it is published.
• Look at your 2025 tax return against the IRMAA thresholds, since that is the return the 2027 surcharge is based on.
• Re-check your voluntary federal withholding on Form W-4V if a higher benefit is likely to push more of it into the taxable range.