Medicare Premiums: What You Pay and Why It Varies

Medicare has four parts, and only some of them charge a monthly premium in the way most people mean when they ask what Medicare costs. Understanding which part you are asking about, and which income year the government is looking at, resolves most of the confusion around why one retiree pays a different amount than their neighbor with a similar-looking income today.

What are the parts of Medicare and what do they cover?

Part A covers hospital care, and is premium-free for most people who, or whose spouse, paid Medicare payroll tax for enough working quarters. This is the 1.45% Medicare tax withheld from every paycheck with no wage ceiling, the same tax discussed in our Social Security wage base guide, and it is effectively a decades-long prepayment for Part A coverage.

Part B covers outpatient care and physician services, and unlike Part A it carries a monthly premium for essentially everyone enrolled, regardless of work history. Part D covers prescription drugs and is offered through private plans, each with its own premium that varies by plan and region. Once Medicare coverage begins, it replaces Marketplace coverage and the premium tax credit that may have applied before, and it also ends eligibility to contribute to an HSA, a rule covered in more detail in that guide.

Both Part B and Part D premiums are affected by the income-related surcharge described below. Part A generally is not, since it has no premium at all for most enrollees.

What is the standard Part B premium?

The government sets a standard monthly Part B premium each year, adjusted based on projected program costs, and most enrollees pay exactly that figure. Check the current standard premium directly from Medicare before budgeting around it, since it changes annually and the change is not tied to general inflation in a fixed, predictable way.

For the current figure, see Medicare.gov's page on Medicare costs, which is updated each fall ahead of the following year.

Why do some people pay more for Medicare?

Because of a surcharge called the income-related monthly adjustment amount, or IRMAA. It adds an extra amount on top of the standard Part B premium, and a separate extra amount on top of your Part D plan's premium, for beneficiaries whose income exceeds set thresholds.

IRMAA works in brackets, similar in structure to how federal income tax brackets work, but with an important difference: IRMAA is not marginal. Crossing into a higher bracket applies that bracket's entire surcharge to your whole premium, not just to the income above the threshold. A single dollar of extra income that pushes you from one bracket into the next can raise your monthly premium by the full jump between bracket amounts, not by a proportional sliver.

Check the current bracket thresholds and surcharge amounts at Medicare.gov's Part B costs page or SSA's guide to Medicare premiums for higher-income beneficiaries before assuming which bracket you fall into.

Why is my Medicare premium based on income from two years ago?

Because the Social Security Administration, which determines your IRMAA bracket, uses the most recently available complete tax return on file with the IRS at the time premiums are set for the coming year. For premiums in a given year, that generally means your tax return from two years prior, since that is the most recent return that has actually been filed and processed by the time the determination is made.

This two-year lookback is the single most misunderstood part of Medicare premiums. Someone who retires this year and sees their income drop sharply will still be assessed IRMAA based on their higher pre-retirement income from two years ago, for up to two years, unless they proactively request a reassessment. The system is not looking at your current bank balance or this year's paycheck. It is looking at a return that may reflect a working life that has already ended.

Can I get an IRMAA surcharge reduced or removed?

Yes, but only through a specific process, and only for specific qualifying reasons. You can request a new initial determination, commonly called an IRMAA appeal, if your income has dropped since the tax year used in the calculation because of a life-changing event recognized by the Social Security Administration. Recognized events generally include:

• Marriage, divorce, or the death of a spouse
• Work stoppage or work reduction, including retirement
• Loss of income-producing property beyond your control
• Loss or reduction of certain pension income
• An employer settlement payment related to closure or bankruptcy

A general market downturn that reduced investment income, or simply the fact that this year's income will be lower than the return on file, does not by itself qualify unless it maps to one of the recognized categories above. Retirement itself does qualify, which is the event that resolves the two-year-lookback problem for most new retirees, but it has to be requested. The adjustment is not automatic.

To request it, you file a form with the Social Security Administration along with documentation of the life-changing event and, typically, evidence of the reduced income, such as a more recent tax return or an estimate. If approved, your premium is recalculated going forward using the more current, lower income figure rather than the two-year-old return.

How does Medicare interact with the Additional Medicare Tax?

They sound related but are structurally separate. The Additional Medicare Tax is an extra 0.9% withheld from wages above $200,000 for a single filer or $250,000 for a married couple filing jointly in 2026, on top of the standard 1.45% Medicare tax with no wage ceiling. This tax funds the Medicare program generally and applies while you are still working and earning wages.

IRMAA, by contrast, is a surcharge on your Medicare premium once you are actually enrolled in Medicare, based on your income from a prior tax year. A high earner still working past 65 could be paying the Additional Medicare Tax on current wages and an IRMAA surcharge on their Part B and Part D premiums at the same time, from two different mechanisms, based on two different measurements of income.

What about people who worked less than the required quarters for premium-free Part A?

If you or your spouse did not accumulate enough quarters of Medicare-taxed work, you can still enroll in Part A, but you pay a monthly premium for it rather than receiving it free. That premium is separate from the Part B premium and from any IRMAA surcharge, and it is generally higher for people with fewer covered quarters than for those closer to but still short of the full requirement.

This situation is uncommon for people with a long US work history but comes up more often for people who spent significant time abroad, were not in paid work for an extended period, or immigrated to the US later in their working life. It is worth checking your own quarters of coverage well before Medicare eligibility age rather than discovering a premium bill for Part A at enrollment.

What determines my household's total Medicare cost each month?

Add together whatever applies to your situation: the Part A premium, if you owe one; the standard Part B premium plus any IRMAA surcharge on Part B; your chosen Part D plan's own premium plus any IRMAA surcharge on Part D; and if you carry a Medicare Advantage or Medigap policy, that plan's separate premium on top of all of the above. Because IRMAA applies separately to Part B and Part D, a higher-income household can see two separate surcharge line items on the same premium notice, not one combined figure.

Does enrolling late make my premium permanently higher?

Separately from IRMAA, Medicare has its own late enrollment penalties, and they compound in a way that surprises people who assume a missed deadline is a one-time inconvenience.

If you do not sign up for Part B when you are first eligible, and you do not qualify for a special enrollment period through active employer coverage, your Part B premium can be permanently increased by a percentage for each full twelve-month period you went without coverage. That penalty is not a flat fee. It is added to your premium for as long as you carry Part B, which for most people means for the rest of their life. The same structure applies to Part D: going 63 days or more without creditable prescription drug coverage after your initial enrollment window closes can trigger its own permanent, separately calculated penalty on your Part D premium.

The employer coverage exception is the detail that matters most here. If you keep working past 65 and are covered by a current employer's group health plan of sufficient size, you can generally delay Part B enrollment without penalty until that employment or coverage ends, at which point a special enrollment period opens. Retiree coverage, COBRA, and coverage through a former employer generally do not count for this purpose, which is a distinction that catches people who assume any employer-sponsored plan protects them from the penalty. Confirming with your plan administrator, in writing, whether your coverage qualifies as active, current employment coverage before you decline Part B is worth doing well ahead of your 65th birthday rather than after the enrollment window has already passed.

Because both the late enrollment penalty and IRMAA can apply to the same premium at the same time, from two entirely different causes, a premium notice that looks unexpectedly high is worth reading carefully rather than assumed to be a single, simple surcharge. One is punishment for a missed deadline. The other is a function of income from a return filed two years earlier. Both show up as the same line item on the same bill, and only one of them responds to an appeal.

The planning takeaway

Because IRMAA looks two years back, the income decisions that matter most for your Medicare premium are usually the ones you made before you were even eligible for Medicare. A large capital gain realized, a big Roth conversion, or a final high-earning year of work, taken at 63 or 64, can quietly set your Medicare premium bracket at 65 and 66, arriving as a bill long after the income itself is gone. Anyone planning a large one-time income event in the years just before Medicare eligibility should model the IRMAA effect two years out, not just the immediate tax bill, using the current thresholds from SSA's guide to Medicare premiums for higher-income beneficiaries. And separately from any income planning, confirm your own enrollment timing and employer-coverage status well before turning 65, since the late enrollment penalty is a permanent cost that no amount of later income planning can undo.