Part B premiums are set from a tax return filed two years before the premium year. So a retiree who converts a traditional IRA to a Roth this year may see nothing unusual on the Medicare bill for months; the effect surfaces two years later, when that return becomes the one Medicare reads. In 2026, the monthly figure that lag produces runs anywhere from $202.90 to $689.90.
Income-Based Tiers Apply to the Part B Premium
Medicare has three premium-bearing parts, and the tiers described here set the standard premium for one of them, Part B.
- Part A, hospital coverage, carries no premium for people who paid Medicare taxes during their working years, regardless of how high income runs later.
- Part D, drug coverage, costs whatever the plan a person picks charges.
- Part B, medical coverage, is tied to modified adjusted gross income, or MAGI, from the tax year two years prior.
That narrows the planning question. Anything that keeps MAGI below the next threshold keeps the Part B premium at the lower amount; anything that pushes MAGI across a line moves the whole premium up a tier.
The 2026 Part B Tiers, Line by Line
These are the 2026 monthly amounts and the income ranges that produce them:
| MAGI — Individual | MAGI — Married Filing Jointly | 2026 Monthly Premium |
|---|---|---|
| $109,000 or less | $218,000 or less | $202.90 |
| $109,000 to $137,000 | $218,000 to $274,000 | $284.10 |
| $137,000 to $171,000 | $274,000 to $342,000 | $405.80 |
| $171,000 to $205,000 | $342,000 to $410,000 | $527.50 |
| $205,000 to $500,000 | $410,000 to $750,000 | $649.20 |
| $500,000 or more | $750,000 or more | $689.90 |
Two things stand out. These are steps, not a gradual slope: a single filer at $109,000 or below pays $202.90, while one just past that boundary is in the $284.10 tier.
And the ranges are republished for each premium year, so the boundaries that apply to a given year are the ones set for that year, not the ones from a prior year's chart.
Roth Withdrawals Stay Out of MAGI; Conversions Don't
Money withdrawn from a Roth IRA comes out tax-free, so it doesn't add to MAGI and doesn't feed the Part B calculation. Roth balances are spending money that leaves the premium tier untouched.
The conversion step is the part with a tail on it. Moving money from a traditional IRA into a Roth counts as taxable income in the year of the conversion. The tax bill arrives with that year's return; the premium change, if there is one, shows up two years behind it.
Say a single filer whose MAGI normally sits below $109,000 completes a conversion large enough to land in the next range.
The return covering that year is the return used to set premiums two years out, so the higher tier applies then, even if income has already dropped back down by the time the bill arrives.
Charitable Distributions Can Satisfy an RMD Without Adding Income
An IRA holder who reaches 73 owes a required minimum distribution every year after that. The withdrawal is taxable income, needed or not, so it lifts MAGI.
A qualified charitable distribution, or QCD, routes part of the withdrawal directly to charity. It counts toward the required minimum distribution while staying out of income.
This is one of the few tools that works in the same year it's used, which is why it comes up mostly for people already in RMD territory rather than for those planning a decade ahead.
HSA Money Spent on Medical Costs Doesn't Count
A withdrawal from a health savings account that pays a medical expense isn't income, so it leaves MAGI where it was. These accounts are tax-advantaged and pair with high-deductible medical insurance, and enrolling in Medicare closes off new contributions without locking up what's already in the account.
For anyone who built a balance before enrolling, that's a pool of money that covers real bills without moving the premium tier.
Tax-Loss Harvesting Offsets Gains That Push MAGI Up
Large capital gains are one of the quicker ways to jump a Part B tier, since they flow straight into MAGI. Tax-loss harvesting works the other direction: selling investments that have lost value creates losses that offset gains, and the net capital loss can reduce taxable income.
The mechanics get technical fast. Which lots are sold, how gains and losses are matched, how the wash-sale rules apply.
This is the sort of thing people generally work through with a financial advisor or tax professional rather than improvising.
Contributions Still Reduce MAGI for People Working Past 65
Plenty of people qualify for Medicare while still drawing a paycheck. Continuing to contribute to a tax-advantaged retirement account lowers MAGI, and older savers have room for extra catch-up amounts: an additional $8,000 a year for those over 50, and $11,250 a year for those between ages 60 and 63.
The IRMAA Appeal and the Life Events That Qualify
The surcharge added for higher income is called the income-related monthly adjusted amount, or IRMAA. Because it's based on a two-year-old return, it can land after income has already fallen — which is what the appeal process exists for.
An appeal goes to the Social Security Administration, and qualifying life-changing events include:
- marriage
- the death of a spouse
- divorce
- loss or reduction of work
Appeals like this generally rest on documentation of the event and of the lower current income, so the paperwork trail matters as much as eligibility.
Someone who retires mid-year and then sees a surcharge based on a full year of salary hasn't necessarily reached the end of the process.
Which Tools Work in Advance, and Which Work Now
The lag sorts these tools into groups. Roth conversions, harvesting decisions, and contribution choices are levers that work ahead of time, since they affect a return that won't set premiums for two more years. QCDs act in the current tax year.
An IRMAA appeal is the one option that comes into play after the surcharge has already appeared, and it's tied to a specific life event rather than to a planning decision.
