The short answer
The Part D IRMAA surcharge adds 14.50 to 91.00 dollars a month in 2026 on top of your drug plan premium, at the same income brackets as Part B's surcharge. It is set from the national base premium, not your plan's price, and Social Security collects it directly.
Plan year 2026. Every figure on this page is the 2026 value, read from Social Security's higher-income premium chart and CMS's 2026 fact sheet on August 7, 2026. The amounts change on a yearly cycle, and this page tracks the current plan year only.
Say you pay your drug plan every month, on time, and then a separate bill turns up from somewhere else. It is not a mistake and your plan cannot fix it, because this charge was never theirs.
What is the Part D IRMAA surcharge?
The Part D IRMAA surcharge is an extra monthly amount higher-income beneficiaries pay on top of their drug plan premium, from 14.50 to 91.00 dollars a month in 2026. Call it the Flat Rider: the law ties it to the national base premium, never to your own plan's price.
The Flat Rider is a reading of Social Security's own explanation. Because individual plan premiums vary, the law specifies the amount is determined using a base premium, so a bargain plan and an expensive plan in the same bracket carry the identical surcharge. The rule is the government's. The naming is ours.
Like its Part B sibling, it touches a minority: approximately 8 percent of people with Part D, per CMS's 2026 fact sheet.
How does it differ from Part B IRMAA?
The Part D IRMAA differs from Part B's in what it rides on and how it is collected. Part B's surcharge joins a premium that is standard nationwide. Part D's rides a national base figure and is deducted from Social Security payments regardless of how you pay your plan.
What the two share is the trigger. One determination letter covers both: Social Security states that if you have both Part B and Medicare drug coverage, you pay higher premiums for each, and if you have only one, the adjustment lands only on the one you have.
So the differences are plumbing, and the sameness is the income test underneath, which the brackets section below completes.
How much is each?
In 2026 the Part B additions run 81.20 to 487.00 dollars a month over the 202.90 dollar standard premium. The Part D additions run 14.50 to 91.00 dollars a month over your plan premium in 2026, per the government's tables, at the same five income steps.
Step by step, the five Part D additions in 2026 are 14.50, 37.50, 60.40, 83.30, and 91.00 dollars a month. Each rides on top of whatever your specific plan charges, which varies by plan.
The two surcharges are the same idea attached to two different premiums, and that is where they part company.
| Part B IRMAA | Part D IRMAA | |
|---|---|---|
| Sits on top of | The standard premium, 202.90 dollars in 2026 | Whatever your own plan charges |
| The 2026 range | 81.20 to 487.00 dollars a month | 14.50 to 91.00 dollars a month |
| Tied to | The standard Part B premium | The national base beneficiary premium |
| If you are billed | Every 3 months | Every month |
The row that surprises people is the third one. Your Part D surcharge is not a percentage of what your plan charges you, so a cheaper plan does not buy a smaller surcharge.
The bracket bounds themselves, five MAGI steps per filing status, are the companion brackets article's territory, and the two tables pair row for row.
How do I pay the Part D surcharge?
You pay the Part D surcharge through Social Security, not through your plan: it is deducted from Social Security benefit payments regardless of how you pay the plan premium itself. Without sufficient benefits to deduct from, it arrives as its own monthly bill from CMS or the Railroad Retirement Board.
The billing rhythm differs by part for people who get bills rather than deductions: Medicare.gov's payment page shows the Part D adjustment billed every month, while a Part B bill, income adjustment included, arrives every 3 months.
The practical consequence is the two-payment month: a plan premium paid to the plan, and a surcharge collected separately by the government, for the same coverage. Neither payment replaces the other, and the plan's own bill will never show the surcharge.
Do both use the same income brackets?
Both surcharges use the same income brackets: one MAGI, measured from the same tax return, sets your step on both ladders at once. In 2026 the entry points are 109,000 dollars for individual filers and 218,000 dollars for joint filers, with five steps above each.
MAGI here is Social Security's definition: total adjusted gross income plus tax-exempt interest income, generally read from the return of two years back, the mechanism the companion lookback article owns.
One consequence follows from the shared ladder: crossing a single bracket bound raises both surcharges in the same year, which is part of why the bracket edges get their own article.
What if I do not have a Part D plan?
Without a Part D plan there is no Part D IRMAA to pay, because the surcharge attaches to the coverage: Social Security applies the adjustment only to the benefit you have. Enroll later in the same year and the adjustment applies automatically when you do.
The wrong-record case has a named fix. If Social Security determines you owe the drug coverage adjustment and you do not actually have Medicare drug coverage, the correction is made with CMS, at 1-800-MEDICARE (1-800-633-4227, TTY 1-877-486-2048), because the coverage records come from CMS.
Whether to carry drug coverage at all is a different decision, with its own economics and its own late enrollment penalty.
What changed this year
The Part D figures on this page are 2026 plan year values, and both ends of the ladder moved. The income line that starts any surcharge rose, and the highest surcharge rose with it. Each figure below carries the year it belongs to.
The highest Part D income-related adjustment is 91.00 dollars a month in 2026, up from 85.80 dollars in 2025. The income line that starts any adjustment at all is 109,000 dollars on an individual return and 218,000 dollars on a joint return in 2026, where in 2025 those were 106,000 dollars and 212,000 dollars.
The adjustment still reaches roughly 8 percent of people with Part D, and it is still added to whatever your plan charges rather than replacing it.
Source: the CMS fact sheets of November 14, 2025 and November 8, 2024.
What this means for you
The Part D surcharge is the smaller number with the odder plumbing: same brackets as Part B, its own flat base, collected through Social Security instead of your plan. In 2026 it spans 14.50 to 91.00 dollars a month, and the letter that sets it explains both surcharges at once.
For the ladder itself, read the brackets article. For the two year delay behind the letter, the lookback article. And if the letter no longer matches your life, the appeal article walks the form.
FAQ
Is the Part D surcharge based on my plan's premium?
No, and that is the design rather than an error. Social Security explains that because individual plan premiums vary, the law specifies the additional amount is determined using a base premium: the adjustment ties to the national base beneficiary premium, not to your own plan's price.
The result is a flat rider per bracket: in 2026 the additions are 14.50, 37.50, 60.40, 83.30, or 91.00 dollars a month, identical whether your plan itself costs little or a lot. Choosing a cheaper drug plan therefore lowers the plan premium but never the surcharge; the only ladder the surcharge answers to is the income ladder.
I pay my plan directly. Why is Social Security deducting more?
Because the law routes the surcharge through Social Security no matter how the plan premium is paid. The page's own words: the amount is deducted from your monthly Social Security payments regardless of how you usually pay your monthly prescription plan premiums.
So a beneficiary who pays the plan directly still sees the income adjustment come out of the benefit payment, and one whose Social Security payment is too small, or who gets none, receives a separate bill from CMS or the Railroad Retirement Board instead.
The plan's bill and the government's deduction never merge, which is why the two amounts have to be added by hand to know the true monthly cost of the coverage.
Does the surcharge apply to drug coverage inside a Medicare Advantage plan?
Social Security frames the adjustment around having Medicare prescription drug coverage. It applies the amount to the benefit you have, so the surcharge follows the drug coverage wherever it lives rather than the label on the plan that carries it. The collection mechanics are unchanged: tied to the national base premium, deducted from Social Security payments or billed separately.
What a specific plan charges as its own premium stays a plan-level fact. For how drug coverage rides inside Advantage plans at all, the Basics article on Medicare Advantage covers the bundling, and this page's rules sit on top of whichever arrangement you hold.
Why did I get two bills for one drug plan?
Almost certainly because the surcharge and the premium travel separately. The plan bills its own premium, while the income adjustment is collected by the government: deducted from Social Security payments when possible, and otherwise billed monthly, per Medicare.gov's payment page, by CMS or the Railroad Retirement Board.
Nothing about the second bill means the first was wrong, and paying the plan more would not retire the surcharge. The check worth doing is against the determination letter, which states both adjustments and the reason, and against the current year's published additions, 14.50 to 91.00 dollars a month in 2026.
The split follows the money. The Part D IRMAA is tied to the base beneficiary premium rather than the price of your own plan (G11), so it is not something your plan can bill you for.
What if I am charged the surcharge but have no drug plan?
That specific error has a named fix and a named agency. Social Security receives drug coverage information from CMS, so if it determines you must pay a higher amount for Medicare drug coverage and you do not have that coverage, the correction is made by calling CMS at 1-800-MEDICARE, 1-800-633-4227, TTY 1-877-486-2048.
It is the one IRMAA correction that neither a form nor a Social Security office resolves, because the underlying record belongs to a different agency. Income disputes go to the IRS, determination disputes to Social Security, and coverage-record disputes to CMS: three doors, and this one is CMS's.
