IRMAA HUBMedicare income-related monthly adjustment · Ref. SSA POMS HI 01101.020

2027 Social Security COLA: What Your Check Will Actually Be

The 2027 cost-of-living adjustment is projected at 3.8 percent, with the official number due mid-October 2026. But the Medicare Part B premium that comes out of most checks is rising too, and if your income puts you in an IRMAA bracket, nothing protects your check from shrinking. Enter your numbers to see your actual 2027 deposit: raise in, Medicare out.

By the IRMAA Hub editorial team· Figures verified against official CMS & SSA sources · Last verified June 2026 · How we calculate

3.8%
Projected 2027 COLA
$218.60
Projected Part B / mo
+$15.70
Part B rise vs 2026
Mid-Oct
Official announcement
Worksheet C-1 · Your 2027 deposit
$
Example

The regular monthly deposit from Social Security. We add your Medicare premium back to find the full benefit your COLA applies to.

Where do I find this number?
Two easy placeseither works
1Your bank statement:the monthly deposit from "SSA TREAS 310". Pick "What lands in my bank" above and enter that.
2Your COLA notice (sent each December: mailed, or online only if you went paperless) or my Social Security: the amount before deductions. Pick "Amount before Medicare".
Either way we handle the Medicare math. If you also have tax withholding taken out of your check, the before-Medicare number is the more exact choice.
2. How do you file your taxes?
$

2027 premiums look at your 2025 return. Below the first IRMAA line? Then you pay the standard premium and this number changes nothing else. We use this one figure for both years; if your 2024 income sat in a different bracket, your deposit now can differ slightly from your statement. Not sure? Work out your MAGI.

Example · Projection · 2027 deposit · single
Your deposit rises about $75.50 a month.

A $91.20 raise, minus $15.70 more for Medicare. You keep about 83 cents of every raise dollar.

Where the raise goes · monthly2026 → 2027
COLA raise (3.8% of your benefit)+$91.20
Part B premium increase-$15.70
Your deposit changes by+$75.50
Deposit now
$2,197.00/mo
Deposit 2027
$2,272.50/mo
Kept of raise
83%
Hold harmless does not need to kick in. Your raise more than covers the premium increase. The rule protects you only if premiums outpace your COLA dollars.

See the 2027 IRMAA brackets →

COLA 3.8% is a projection (Senior Citizens League, unchanged since May 2026); 2027 premiums are the projected sliding scale. Official figures publish mid-October 2026 (COLA) and about November (premiums); this page updates the day they do.Your numbers never leave this page.

Estimates rounded to the cent; Social Security applies its own rounding rules to the final amount. Premium figures come from the projected 2027 sliding scale and official 2026 figures.

Why some checks shrink even in a COLA year

Most people are protected by the hold-harmless rule: if the Part B premium increase would exceed your COLA dollars, the premium is capped so your deposit cannot fall. That protection has four exceptions, and the largest one is income. Anyone paying an IRMAA surcharge is outside hold harmless entirely: the full premium increase lands no matter what the COLA covers.

New enrollees, people whose premiums are not deducted from a check, and people whose premiums Medicaid pays are the other three exceptions. If you are near an IRMAA threshold, the difference between brackets is worth far more than the COLA itself: check the 2027 IRMAA brackets, and if your income has dropped since 2025 because of retirement or another life event, Form SSA-44 can move you down.

For how your benefit and IRMAA interact the rest of the year, read Social Security and IRMAA.

Common questions

How much is the 2027 Social Security COLA?
It is not official yet. The widely followed Senior Citizens League projection has held at 3.8% since May 2026. The official figure is set by comparing average CPI-W for July, August, and September 2026 against the same months of 2025, and the Social Security Administration announces it in mid-October 2026.
When does the 2027 COLA show up in my check?
With the January 2027 payments. Social Security mails a COLA notice in December showing your new benefit amount, and the my Social Security portal shows it in early December as well.
Why does my check go up less than the COLA?
Because the Medicare Part B premium deducted from most checks rises at the same time. The projected 2027 standard premium takes a bite out of the raise, and anyone in an IRMAA bracket loses more. The worksheet above shows the exact split for your numbers.
What is the hold harmless rule?
A protection for people whose Part B premium is deducted from their check: the premium increase cannot exceed their COLA dollar increase, so the deposit cannot fall. It does not protect four groups: people paying IRMAA, new enrollees, people whose premiums are not deducted from a check, and people whose premiums Medicaid pays.
Does the COLA change my IRMAA bracket?
No. IRMAA is set by your income from two years earlier, not by your benefit amount. A bigger benefit can nudge your taxable income up over time, but the 2027 surcharge itself depends on your 2025 tax return.
Is Part D included in this math?
Partly no. Part D plan premiums go to your insurer and are not part of this deposit. The Part D IRMAA surcharge is different: if you owe it, it is usually withheld from your Social Security check too, so an IRMAA payer's deposit drops by a little more than shown here.

Sources: 42 U.S.C. 415(i) (COLA computation); CRS Report R40082 (Part B premiums and hold harmless); The Senior Citizens League 2027 COLA projection (July 2026); projected 2027 IRMAA sliding scale, official 2026 figures from SSA and CMS. The 3.8% COLA and 2027 premiums are projections until the official releases; this page is updated when they publish. Informational only, not financial or tax advice. Last verified August 2026.