How Does a Roth Conversion Affect Medicare IRMAA?

You’re considering a Roth conversion.

The tax numbers look good.

Then somebody says:

“Be careful. That could increase your Medicare premiums.”

And suddenly the entire strategy feels like a mistake.

But is it?

A Roth conversion can increase the income used in determining Medicare IRMAA.

That can potentially increase what you pay for Medicare Part B and Part D.

But here’s the part that gets missed:

Paying more for Medicare doesn’t automatically mean the Roth conversion was a bad decision.

You have to compare the additional Medicare cost against what the conversion may accomplish elsewhere.

Future RMDs.

Future taxable income.

Roth assets.

Retirement income.

Your surviving spouse.

Your legacy.

That’s why we don’t look at IRMAA by itself.

We make IRMAA compete against the rest of the retirement math.

Quick Answer: Does a Roth Conversion Affect Medicare IRMAA?

It can.

Previously untaxed traditional IRA amounts converted to a Roth IRA are generally included in gross income for the year of the conversion.

That additional income can increase the modified adjusted gross income used for Medicare’s income-related monthly adjustment amount, commonly called IRMAA.

IRMAA can increase the cost of Medicare Part B and Part D.

But IRMAA shouldn’t be evaluated in isolation.

The stronger question is:

“Does the long-term projected benefit of the Roth conversion justify the additional taxes and Medicare costs created along the way?”

What Is Medicare IRMAA?

IRMAA stands for Income-Related Monthly Adjustment Amount.

Most Medicare beneficiaries pay the standard Part B premium.

Higher-income beneficiaries can pay an additional amount for Part B.

Medicare Part D also has a separate income-related adjustment for higher-income beneficiaries.

Think of IRMAA as an additional Medicare cost tied to income.

And that’s exactly why Roth conversions can matter.

A taxable conversion can increase income.

What Are the 2026 Medicare IRMAA Thresholds?

For 2026, the standard Medicare Part B premium is $202.90 per month.

The first Part B IRMAA tier begins when modified adjusted gross income exceeds:

• $109,000 for an individual tax return
• $218,000 for married couples filing jointly

Higher income levels can produce progressively higher Part B premiums.

Part D has separate income-related monthly adjustment amounts using the same general income tiers for these filing statuses.

These thresholds and premium amounts can change from year to year.

2026 Medicare Part B IRMAA Example

Here’s a simplified look at the 2026 Part B structure for individual and joint filers:

Married people filing separately under certain circumstances have a different IRMAA structure.

And remember, Part D can have an additional IRMAA charge too.

How Can a Roth Conversion Trigger IRMAA?

Imagine you’re married and retired.

Before the Roth conversion, your income used for the Medicare calculation is below an applicable IRMAA threshold.

Then you convert a large amount from your traditional IRA to a Roth IRA.

The taxable portion of that conversion generally increases your gross income.

That additional income could push your modified adjusted gross income above an IRMAA threshold.

Now your conversion didn’t just create an income-tax consequence.

It may have created a Medicare consequence too.

Why Can IRMAA Feel Like a Tax Cliff?

This is one of the frustrating parts.

Income-tax brackets are marginal.

IRMAA works differently.

Crossing into a higher IRMAA income tier can cause the applicable higher Medicare premium adjustment to apply.

That’s why people sometimes obsess over staying one dollar below an IRMAA threshold.

And sometimes staying below a threshold can make mathematical sense.

But not always.

Should You Keep Your Roth Conversion Below the IRMAA Threshold?

This is where I don’t want a rule of thumb making the decision.

Imagine your projected income is close to an IRMAA threshold.

You could reduce the Roth conversion to stay below it.

That sounds logical.

But what happens to the money you didn’t convert?

It stays in the traditional IRA.

It may continue growing.

It may contribute to larger future RMDs.

It may create taxable income later.

So before automatically stopping the conversion at an IRMAA threshold, I want to know:

“What does avoiding this Medicare cost do to the rest of the retirement plan?”

Sometimes Paying IRMAA Can Still Produce the Better Projected Result

This surprises people.

They assume:

“If the conversion triggers IRMAA, we did something wrong.”

Not necessarily.

Imagine two strategies.

Strategy A: Keep the conversion smaller to remain below a projected IRMAA threshold.

Strategy B: Convert more, intentionally accept some additional projected Medicare cost, and move more money out of the traditional IRA.

Strategy B might produce:

• More conversion tax today
• Higher projected Medicare premiums for a period
• More money moved to Roth
• Lower projected future traditional IRA balances
• Lower projected future RMDs
• A different long-term tax result

Does that make Strategy B better?

We don’t know yet.

That’s why we run the math.

Our Roth Blueprint Software Can Analyze Thousands of Potential Scenarios

This is exactly where our Roth Blueprint software becomes valuable.

We’re not limited to asking:

“Does this conversion trigger IRMAA?”

We can assess thousands of potential modeled scenarios involving:

• Different Roth conversion amounts
• Different starting years
• Different conversion timelines
• Different tax-bracket targets
• Projected RMDs
• Social Security income
• Pension income
• Other retirement income
• Potential Medicare IRMAA exposure

Then we can compare the projected results.

The goal is to identify a conversion strategy that reduces unnecessary projected taxes, RMDs, and Medicare costs without sacrificing the larger retirement objective just to avoid one threshold.

Roth Blueprint Can Compare Different IRMAA Strategies

Imagine we’re considering a multi-year Roth conversion.

We can model one scenario designed to remain below a particular IRMAA threshold.

Then another scenario that uses more of the available tax-bracket space and crosses that IRMAA threshold.

Then another conversion amount.

Then another timeline.

Now we’re comparing actual modeled strategies instead of saying:

“IRMAA is bad, so never cross the line.”

Can You Target Both a Tax Bracket and an IRMAA Threshold?

We can include both in the modeling.

This is where retirement tax planning becomes more interesting.

You may have room left inside the marginal federal income-tax bracket you’re targeting.

But using all of that room could push projected MAGI into a higher IRMAA tier.

Now there are two targets competing with each other.

Tax-bracket efficiency versus Medicare-premium efficiency.

That’s exactly the kind of tradeoff we want Roth Blueprint to evaluate.

The Lowest Tax Conversion Isn’t Always the Lowest Total-Cost Conversion

Imagine someone builds a Roth conversion strategy solely around federal tax brackets.

It looks great.

Then Medicare costs show up later.

That’s not a complete analysis.

The opposite mistake is building the entire conversion around avoiding IRMAA.

Now maybe you save money on Medicare but leave a much larger traditional IRA behind.

That isn’t a complete analysis either.

We want to look at the combined cost.

Why the Two-Year IRMAA Lookback Matters

This catches people off guard.

Medicare generally uses income information from your tax return from two years earlier when determining IRMAA.

So a conversion can create a delayed Medicare effect.

You make the conversion.

The tax bill comes.

You move on.

Then later, your Medicare premium changes.

Your reaction is:

“Why did Medicare go up? My income isn’t that high anymore.”

Because Medicare may be looking backward at an earlier income year.

Example: Roth Conversion Before Age 65

Suppose you’re 63 and planning a Roth conversion.

You’re not on Medicare yet.

It’s easy to think:

“IRMAA doesn’t matter because I don’t have Medicare.”

Not so fast.

The income created by a conversion before Medicare enrollment can potentially matter later because of Medicare’s lookback rules.

That’s why the years immediately before Medicare need to be modeled carefully too.

Example: Roth Conversion at Age 65

Now imagine you’re 65 with $1 million in a traditional IRA.

You’re newly retired.

Your salary is gone.

You see a potential Roth conversion opportunity.

Great.

But now Medicare belongs in the analysis.

We can compare:

• No conversion
• A conversion designed around a selected IRMAA threshold
• A larger conversion that crosses the threshold
• Different tax-bracket targets
• Different multi-year conversion schedules

Then we see which one makes the stronger mathematical case.

Example: You’re 68 With $1.5 Million in an IRA

Now RMDs are getting closer.

You may already have Social Security.

You have Medicare.

Your IRA may still be growing.

You look at IRMAA and think:

“I don’t want my Medicare premiums going up.”

I understand that.

But I also want to know what happens if we leave $1.5 million sitting in the traditional IRA.

What are the projected RMDs?

What does the future taxable-income picture look like?

What happens if one spouse dies?

That’s the comparison.

How Does Social Security Fit Into Roth Conversion and IRMAA Planning?

Social Security adds another layer.

Conversion income can interact with the calculation used to determine how much of your Social Security benefits are included in taxable income.

And the resulting income picture can also affect Medicare IRMAA.

That’s why a conversion before Social Security starts can look different from the same conversion after benefits begin.

The conversion amount didn’t change.

The surrounding income did.

How Do RMDs Fit Into the IRMAA Problem?

This is where avoiding IRMAA today can potentially create another problem later.

Suppose you repeatedly limit Roth conversions because you’re afraid of crossing an IRMAA threshold.

More money stays in your traditional IRA.

Then RMDs eventually begin.

Those required distributions create taxable income.

That income itself may affect future Medicare costs.

So you may avoid IRMAA during the conversion years only to encounter IRMAA later because of larger RMDs.

That’s why the software needs to look beyond one year.

Could a Roth Conversion Reduce Future IRMAA Exposure?

Potentially.

A Roth conversion can increase income during the conversion year.

But moving eligible money out of a traditional IRA can reduce the amount remaining there compared with leaving those same dollars in the traditional account.

That may reduce future RMDs.

Lower future RMDs could create a different future MAGI picture.

So a Roth conversion can potentially create more IRMAA exposure during one period while reducing projected exposure during another.

That’s exactly why judging the strategy from one Medicare premium notice can be misleading.

What If You’re Married?

For 2026, the first IRMAA threshold for married couples filing jointly begins above $218,000 of MAGI.

But married couples also have another issue to think about.

Eventually, one spouse may be left managing the retirement plan alone.

The household may lose one Social Security benefit.

Other income may change.

And the surviving spouse may eventually file as a single taxpayer.

That can create a very different tax and Medicare picture.

So I don’t want to model Roth conversions only around today’s joint return.

I want to see what the surviving-spouse scenario looks like too.

IRMAA Can Become an Emotional Decision

This happens all the time.

You open a Medicare notice and see your premium went up.

It feels like a penalty.

You think:

“We shouldn’t have done that conversion.”

Maybe that’s true.

But maybe the conversion created $3,000 of additional Medicare cost while improving the projected long-term retirement result by substantially more.

Or maybe the Medicare cost made the conversion unattractive.

The notice alone doesn’t tell us.

A visible cost feels worse than an invisible future cost.

That’s one of the psychological traps in Roth conversion planning.

“I Don’t Want to Pay More for Medicare”

I understand that reaction.

You spent your career paying into the system.

Now you’re retired and somebody tells you that voluntarily creating taxable income could increase your Medicare premiums.

Your response is:

“Why would I do that to myself?”

Because the Medicare premium is only one part of the equation.

If paying an additional cost today produces a substantially stronger projected retirement result, it may be worth considering.

If it doesn’t, we shouldn’t do it just because somebody likes Roth conversions.

Make the strategy prove itself.

The Retirement Math Method™

This is exactly why we use our Retirement Math Method™.

We start with your current retirement path.

No conversion.

Then we use Roth Blueprint software to assess thousands of potential modeled scenarios.

We can compare:

• Different conversion amounts
• Different starting years
• 2-year conversion strategies
• 3-year conversion strategies
• 5-year conversion strategies
• Longer multi-year strategies
• Different tax-bracket targets
• Different potential IRMAA outcomes
• Projected RMDs
• Social Security income
• Traditional IRA balances
• Roth balances
• Surviving-spouse outcomes
• Legacy outcomes

Then we let the strategies compete.

Maybe avoiding IRMAA wins.

Maybe intentionally accepting some IRMAA produces the stronger projected result.

That’s what the math needs to tell us.

Can Roth Blueprint Guarantee You Won’t Pay IRMAA?

No.

And that’s not what the software is designed to promise.

Medicare thresholds can change.

Tax laws can change.

Your income can change.

Your investments can change.

Your conversion strategy can change.

What Roth Blueprint allows us to do is model potential IRMAA exposure alongside thousands of Roth conversion scenarios using the information and assumptions available.

That gives us a much stronger basis for making the decision than simply trying to stay under one income number.

Can We Adjust the Roth Conversion Each Year?

Yes.

This is one of the most useful parts of a multi-year strategy.

Maybe the original analysis calls for a five-year conversion.

That doesn’t mean the conversion amount has to remain identical every year.

Before the next conversion, the numbers can be reviewed again.

Maybe your income changed.

Maybe Social Security started.

Maybe your IRA balance changed.

Maybe Medicare thresholds changed.

Maybe you realized capital gains.

Then the conversion amount can be reconsidered.

A Roth conversion timeline should be managed, not put on autopilot.

What Should You Model Before Doing a Roth Conversion on Medicare?

• Your current MAGI
• Your filing status
• Your proposed conversion amount
• Your current marginal federal tax bracket
• Your selected tax-bracket target
• Your Medicare status
• Potential Part B IRMAA
• Potential Part D IRMAA
• Social Security income
• Pension income
• Investment income
• Capital gains
• Projected RMDs
• Your traditional IRA balance
• Your Roth balance
• Your spouse’s situation
• Your projected surviving-spouse scenario
• The no-conversion scenario

Frequently Asked Questions About Roth Conversions and IRMAA

Does a Roth conversion count toward Medicare IRMAA?

Taxable Roth conversion income generally increases adjusted gross income and can increase the modified adjusted gross income used for Medicare IRMAA calculations.

Can a Roth conversion increase Medicare Part B premiums?

Yes. If conversion income increases MAGI above an applicable IRMAA threshold, the beneficiary may pay an income-related adjustment in addition to the standard Part B premium.

Can a Roth conversion increase Medicare Part D costs?

Yes. Medicare Part D also has income-related monthly adjustment amounts for higher-income beneficiaries.

What is the first IRMAA threshold for 2026?

For 2026, the first Part B IRMAA tier begins above $109,000 of MAGI for individual filers and above $218,000 for married couples filing jointly. Other filing situations have separate rules.

What is the standard Medicare Part B premium in 2026?

The standard Medicare Part B monthly premium for 2026 is $202.90. Beneficiaries subject to IRMAA can pay more.

Should I stop my Roth conversion before I cross an IRMAA threshold?

Not automatically. Staying below an IRMAA threshold may reduce projected Medicare costs, but the strategy should also be evaluated against projected taxes, RMDs, Roth assets, and the broader retirement result.

Can paying IRMAA ever make sense during a Roth conversion?

It can be worth considering when the additional projected Medicare cost is outweighed by other projected benefits of the conversion. The complete strategy should be modeled rather than judging the conversion solely by the Medicare cost.

Does Medicare look back two years for IRMAA?

Medicare generally uses income information from the tax return from two years earlier when determining IRMAA.

Can a Roth conversion before age 65 affect Medicare later?

It can. Because of Medicare’s income lookback, conversion income from a year before Medicare enrollment may be relevant to a later IRMAA determination.

Can Roth Blueprint model IRMAA?

Our Roth Blueprint software can assess thousands of potential modeled Roth conversion scenarios and include potential Medicare IRMAA exposure alongside conversion taxes, tax-bracket targets, projected RMDs, Social Security, and other retirement income.

Can Roth Blueprint model a conversion that stays below an IRMAA threshold?

We can model conversion amounts around selected income targets, including scenarios intended to remain below a projected IRMAA threshold. We can also compare those scenarios with larger conversions to determine which produces the stronger modeled retirement outcome.

Can a Roth conversion reduce future IRMAA?

Potentially. Moving eligible money out of a traditional IRA can reduce the amount remaining in that account compared with leaving those same dollars there. This may reduce future RMDs and could change future MAGI and IRMAA exposure. The outcome should be modeled rather than assumed.

Don’t Let IRMAA Make the Roth Conversion Decision for You

IRMAA matters.

We should calculate it.

We should model it.

We should try to avoid unnecessary Medicare costs.

But I wouldn’t automatically destroy an otherwise strong Roth conversion strategy just to stay below one Medicare threshold.

First ask:

“What does staying below this threshold save me?”

Then ask:

“What does staying below it cost me somewhere else?”

That’s the comparison most people never see.

Want to See How IRMAA Changes Your Roth Conversion Strategy?

If you’re approaching Medicare or already enrolled and have $500,000 or more in IRAs, 401(k)s, or other tax-deferred retirement accounts, we can model this before you make the conversion.

Using our Roth Blueprint software and Retirement Math Method™, we can assess thousands of potential scenarios.

Different conversion amounts.

Different conversion years.

Different tax-bracket targets.

Different potential IRMAA outcomes.

Different projected RMDs.

And the no-conversion strategy.

Then we compare them.

You see the projected taxes.

You see the potential Medicare costs.

You see the RMD projections.

You see the tradeoffs.

Then you decide.

We don’t sell you a retirement strategy. We run the math and let you decide.

Schedule Your No-Pressure Retirement Strategy Appointment

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Important Disclosure

This article is for educational purposes only and isn’t intended as individualized tax, legal, investment, accounting, insurance, Medicare, Social Security, or retirement-planning advice. Medicare premiums, IRMAA thresholds, tax laws, and other rules can change. The Medicare figures discussed in this article are 2026 figures and should be verified for the year in which a strategy is implemented. Roth conversions can create significant taxable income and may affect Medicare premiums, Social Security taxation, and other parts of your financial situation. Roth Blueprint calculations and other financial projections are based on assumptions and information entered into the analysis. They cannot guarantee a particular tax result, the lowest possible tax liability, the elimination or minimization of RMDs, or the avoidance or minimization of Medicare IRMAA. Before implementing a Roth conversion, consider working with qualified financial and tax professionals who can evaluate your individual circumstances.