Quick Answer
In 2026, the standard Medicare Part B premium is $202.90 per month. Higher-income beneficiaries pay more through IRMAA. The surcharge is based on modified adjusted gross income and filing status, and it can also add a Part D income-related adjustment.
What A Medicare Surcharge Calculator Should Estimate
A useful calculator should not only ask for income. It should estimate the income number Medicare cares about, identify the household's filing status, count how many people are on Medicare, and show the next threshold. Without those details, the result can be misleading.
For retirement planning, the most useful output is often not just "your premium." It is "how much income room do you have before the next premium tier?" That is the number that matters when deciding on a Roth conversion, capital gain, or extra IRA withdrawal.
Part B And Part D Are Separate
IRMAA has two Medicare pieces:
- Part B IRMAA: a higher monthly Part B premium.
- Part D IRMAA: an income-related adjustment added separately from the drug plan premium.
A person can owe the Part D adjustment even though the actual Part D plan premium is paid to a private plan. Medicare's income adjustment is separate from the plan's own price.
Example
A single filer with IRMAA MAGI of $120,000 is above the first 2026 single threshold of $109,000 but below $137,000. In the 2026 table, that places the person in the first IRMAA tier. The monthly estimate is the higher Part B amount plus the Part D IRMAA amount, before the person's actual Part D plan premium.
For a married couple filing jointly, the first threshold is $218,000. If both spouses are on Medicare, the Part B and Part D IRMAA effect may apply to both people.
Income Events That Can Trigger The Surcharge
- Roth conversions.
- Traditional IRA or 401(k) withdrawals.
- Large capital gains.
- Business income.
- Taxable Social Security increases caused by other income.
- Tax-exempt interest, because it is added back for IRMAA MAGI.
Important Timing Note
Medicare usually looks at a prior tax return when setting premiums. A 2026 premium is generally tied to earlier income data. A 2026 Roth conversion normally affects a future premium year, not the 2026 bill itself. Because future thresholds are not known yet, a current-year calculator is best used as a planning proxy.
Next step: Estimate the premium tier, monthly amount, and next threshold in one place.
Use the Medicare surcharge calculator