IRMAA Avoidance and MAGI Planning Across Calendar Years

IRMAA planning is not just "keep income low." It is calendar-year income choreography.

Medicare looks at your Modified Adjusted Gross Income from a prior tax year and uses it to set future Part B and Part D premiums. That means a December Roth conversion, a year-end capital gain, a delayed bonus, or the first year of RMDs can affect Medicare premiums two years later.

The mistake is treating IRMAA as a Medicare problem only. In practice, IRMAA is a tax planning problem with a Medicare bill attached.

The Two-Year Lookback

IRMAA generally uses MAGI from two years prior. Your 2026 MAGI affects 2028 Medicare premiums. Your 2027 MAGI affects 2029 premiums.

That lag creates two planning challenges:

1. You may not feel the cost until long after the income decision
2. A good tax move in one year can become a bad Medicare-premium move later

If you convert $120,000 to Roth at age 63, the tax bill happens immediately. The Medicare surcharge may show up at 65. If you do not model both, you can underestimate the true cost of the conversion.

MAGI Sources That Matter

For IRMAA, MAGI starts with Adjusted Gross Income and adds tax-exempt interest. Common drivers include:

• wages and self-employment income
• Traditional IRA and 401(k) withdrawals
• Roth conversions
• Required Minimum Distributions
• taxable pension income
• taxable Social Security
• interest and dividends
• realized capital gains
• rental income
• SPIA and QLAC annuity payments
• tax-exempt municipal bond interest

Qualified Roth withdrawals generally do not count. HSA withdrawals for qualified medical expenses generally do not count. Spending cash from a bank account generally does not count.

That difference is powerful. Two retirees can spend the same $100,000, but one can produce much higher MAGI depending on which accounts fund the spending.

Why Calendar Years Matter

IRMAA thresholds apply to annual MAGI. A transaction on December 31 counts in that year. A transaction on January 1 counts in the next year.

That makes timing valuable:

• Sell appreciated stock in January instead of December if this year is already near a threshold
• Split Roth conversions across two tax years
• Bunch charitable giving into high-income years if using itemized deductions
• Coordinate pension start dates and Social Security claiming
• Avoid combining a large conversion with an unusual capital gain in the same year

The point is not to avoid income forever. It is to avoid stacking avoidable income into the same calendar year.

The Cliff Problem

IRMAA is tiered. Once MAGI crosses a threshold, the premium jumps to the next tier. It is not a gradual phase-in on only the excess dollars.

That means the last few dollars before a threshold are unusually valuable. If a $5,000 conversion pushes you $500 over a tier, the entire year can carry the higher premium. For a married couple, both spouses on Medicare may pay the surcharge.

The Retirement Transition Year

The year you retire often has messy income:

• final salary
• bonus or commission
• unused vacation payout
• severance
• stock compensation
• consulting income
• pension start
• capital gains from portfolio cleanup

Doing a large Roth conversion in that same year can be a mistake. You may already have enough taxable income to fill the bracket and potentially trigger future IRMAA.

Often, the better approach is:

1. Let the final work-income year be what it is
2. Use the first full low-income retirement year for conversions
3. Watch ACA subsidies if you are under 65
4. Watch IRMAA if you are already 63+ or on Medicare

Roth Conversions and IRMAA

Roth conversions are one of the best retirement tax tools. They are also one of the easiest ways to trigger IRMAA.

The right planning question is not "Should I convert?" It is:

How much can I convert before the combined cost of tax plus IRMAA becomes too high?

A conversion plan should show:

• baseline MAGI before conversion
• federal and state tax bracket headroom
• IRMAA threshold headroom
• ACA subsidy impact if under 65
• Social Security taxation impact if claiming
• which tax year controls which Medicare premium year

ModernRetire's tax strategy workflow handles this by treating IRMAA as a constraint, not an afterthought.

Capital Gains and Portfolio Rebalancing

Capital gains are easy to overlook because they may not feel like income. For IRMAA, realized gains count.

That matters when you:

• sell concentrated stock
• rebalance a taxable portfolio
• sell a rental property
• harvest gains in a low-bracket year
• downsize and invest taxable proceeds

Tax-gain harvesting can be smart, especially in low-income years. But if you are near an IRMAA threshold, the gain may carry a Medicare cost that changes the decision.

RMD Years

Required Minimum Distributions can create a structural IRMAA problem. Once RMDs begin, you may have less control over ordinary income.

This is why many IRMAA strategies start earlier:

• convert pre-tax dollars before RMDs
• delay Social Security when appropriate
• build Roth balances for tax-free spending
• use Qualified Charitable Distributions after eligible age
• consider QLACs when appropriate for longevity risk and RMD reduction

The goal is to reduce forced taxable income later, not just minimize tax this year.

Life-Changing Event Appeals

If your income falls because of a qualifying life-changing event, you may be able to appeal IRMAA using Form SSA-44.

Common qualifying events include:

• work stoppage
• work reduction
• marriage
• divorce or annulment
• death of a spouse
• loss of pension income
• loss of income-producing property in certain circumstances

Retirement is the big one. If Medicare uses a high-income work year to set your premium after you retire, an appeal may let SSA use a more representative income estimate.

A Practical Calendar-Year Checklist

Use this before year-end:

1. Estimate full-year MAGI

Include wages, pensions, taxable withdrawals, conversions, capital gains, dividends, interest, rental income, taxable Social Security, and tax-exempt interest.

2. Compare against IRMAA thresholds

Check the current CMS/Medicare thresholds for your filing status. Use a buffer because year-end tax numbers can move.

3. Decide conversion amount last

Do not set Roth conversion size before estimating gains, dividends, and other income. Conversion is the flexible lever; use it after fixed income is known.

4. Separate one-time events

If you have a business sale, home sale, severance, large capital gain, or pension lump sum, consider whether Roth conversion should wait.

5. Map tax year to premium year

Write it down: "2026 MAGI affects 2028 Medicare premiums." This makes the delayed cost visible.

Key Takeaways

• IRMAA is based on calendar-year MAGI and a two-year lookback
• Roth conversions, capital gains, RMDs, and tax-exempt interest can all count
• Qualified Roth withdrawals and HSA medical withdrawals usually do not increase MAGI
• Avoid stacking avoidable income into the same year
• Model federal tax, state tax, ACA, Social Security taxation, and IRMAA together
• Use Form SSA-44 when a qualifying life-changing event makes old income unrepresentative

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