How these projections are built
The five IRMAA tiers are not arbitrary dollar amounts. Statute sets each tier as a share of the total cost of Part B coverage, at 35%, 50%, 65%, 80% and 85% against the standard 25%, which makes each tier a fixed multiple of the standard premium. Checking those multiples against the official 2026 figures:
| Tier | Multiple of standard | Our calculation | Official 2026 premium |
|---|---|---|---|
| Standard | 1.0 | $202.90 | $202.90 |
| 1 | 1.4 | $284.06 | $284.10 |
| 2 | 2.0 | $405.80 | $405.80 |
| 3 | 2.6 | $527.54 | $527.50 |
| 4 | 3.2 | $649.28 | $649.20 |
| 5 | 3.4 | $689.86 | $689.90 |
The multiples reproduce every published 2026 amount to within a few cents, so a projected standard premium yields projected tier premiums with the same accuracy. The one figure nobody can derive this way is the income threshold, which CMS indexes to inflation and publishes each November. This page uses the official 2026 thresholds and labels them as such, which still tells you your margin to within a few hundred dollars.
The 2026 brackets, which set your expectations for 2027
| Single filer MAGI | Married filing jointly | Part B 2026 | Part D surcharge |
|---|---|---|---|
| $109,000 or less | $218,000 or less | $202.90 | $0 |
| $109,001 to $137,000 | $218,001 to $274,000 | $284.10 | $14.50 |
| $137,001 to $171,000 | $274,001 to $342,000 | $405.80 | $37.50 |
| $171,001 to $205,000 | $342,001 to $410,000 | $527.50 | $60.40 |
| $205,001 to $499,999 | $410,001 to $749,999 | $649.20 | $83.30 |
| $500,000 or more | $750,000 or more | $689.90 | $91.00 |
Married filing separately uses its own compressed schedule, with the top surcharge arriving above $397,000.
IRMAA is a cliff, and that changes your planning
Income tax works in slices: a dollar over a bracket edge is taxed at the higher rate, and the dollars below it are not. IRMAA works on your whole income. Cross the first threshold by one dollar as a single filer and your Part B premium rises about 40% for all twelve months, and the Part D surcharge arrives on top. In 2026 that single dollar cost $1,750.
A married couple pays it twice, because each spouse on Medicare pays their own premium and their own surcharge. One dollar over the joint threshold costs a couple roughly $3,500 for the year.
The planning response is to manage the income that lands in your 2025 and 2026 returns, since those set your 2027 and 2028 premiums. Roth conversions, capital gains harvesting, the sale of a rental property and a large required minimum distribution all push MAGI up two years before you feel it. Converting $30,000 to a Roth in a year when it tips you over a threshold adds the conversion tax plus the surcharge.
Appealing with Form SSA-44
Social Security will recalculate your premium when a life-changing event has cut your income since the tax year it used. File Form SSA-44 and bring evidence. Qualifying events include retirement or reduced work hours, the death of a spouse, marriage or divorce, the loss or reduction of a pension, and the sale or closure of a business you operated.
A large one-off capital gain is not a life-changing event, which catches out people who sold a house in 2025 and discovered the consequence in their 2027 premium notice. The surcharge lasts one year and falls away when your 2026 return replaces the 2025 one.
What this does to your Social Security raise
Medicare deducts Part B straight from your benefit, so the premium increase arrives in the same January payment as your COLA. The COLA 2027 calculator runs both numbers together and shows the raise that survives. Paying an IRMAA surcharge also removes your hold harmless protection, so your net deposit can fall from one year to the next even though the COLA is positive.
Frequently asked questions
When does CMS announce the 2027 premium?
November 2026, usually in the second week, together with the deductible and the IRMAA thresholds.
Why does Social Security use income from two years ago?
It uses the most recent return the IRS has finished processing. Your 2026 return is not available when 2027 premiums are set in late 2026.
Does IRMAA apply to Medicare Advantage?
Yes. You pay the Part B premium and any surcharge whatever plan delivers your benefits, plus whatever the plan charges.
Is the Part D surcharge separate from my plan premium?
Yes. Social Security collects the surcharge, and your drug plan bills its own premium separately.
What counts in MAGI for IRMAA?
Adjusted gross income plus tax-exempt interest. Municipal bond interest is excluded from income tax and still counts here.
Does the standard deduction reduce MAGI?
No. MAGI sits above the standard deduction, so the 65+ deduction cuts your tax bill without moving your IRMAA bracket. The Schedule 1-A calculator estimates that deduction.