IRMAA Planning in Retirement: How Income Affects Medicare Premiums and What to Watch For
Most retirees understand that Medicare Part B carries a monthly premium. Fewer understand that the premium they pay in any given year is determined by income they reported two years earlier, and that income from investment distributions, Roth conversions, required minimum distributions, can push them into a surcharge tier that adds thousands of dollars to that premium with no warning. IRMAA planning in retirement is the practice of understanding how modified adjusted gross income interacts with those surcharge thresholds.
IRMAA planning in retirement is not Medicare planning in the sense of selecting a plan or evaluating coverage. It is income and tax planning with a Medicare cost dimension that many retirees discover only after the surcharge has already been assessed.
Post Oak Private Wealth Advisors works with retirees who need to evaluate IRMAA planning in retirement as part of a coordinated income and tax strategy.
What IRMAA Is and Why It Surprises So Many Retirees
IRMAA stands for Income-Related Monthly Adjustment Amount. It is a surcharge imposed on top of standard Medicare Part B and Part D premiums for beneficiaries whose income exceeds specified thresholds. The surcharge is assessed by the Social Security Administration based on MAGI reported to the IRS two years prior.
The standard Medicare Part B premium in 2024 is approximately $174.70 per month per person. IRMAA surcharges apply on top of that amount in steps, not on a smooth curve. Crossing from one threshold tier to the next produces a discrete jump in the monthly premium per enrollee. For a married couple both enrolled in Medicare, surcharges are assessed on each person separately, which means the household-level cost of crossing a tier boundary is approximately double the per-person figure.
IRMAA planning in retirement begins with recognizing that the standard premium is the floor, not the expected cost, for retirees with income above the base tier. For retirees with pension income, deferred compensation distributions, Social Security, required minimum distributions, and investment income all active simultaneously, the base tier is often not where they land, and the surcharge can represent a material and ongoing annual cost. Learn how we approach tax planning in retirement.
How MAGI Is Calculated for IRMAA Purposes
IRMAA planning in retirement requires clarity on what counts as MAGI for surcharge determination purposes, because the definition differs slightly from the adjusted gross income figure on the front of Form 1040.
For IRMAA purposes, MAGI is adjusted gross income plus tax-exempt interest income. The primary sources of tax-exempt interest that affect this calculation are municipal bond interest, which is excluded from AGI but added back for IRMAA, and certain savings bond interest excluded under income limits.
The income items that most frequently contribute to MAGI and trigger or worsen IRMAA surcharges for retirees include:
Traditional IRA and 401(k) distributions, including both voluntary withdrawals and required minimum distributions, which are 100 percent ordinary income
Deferred compensation distributions, which are fully ordinary income in the year received
Social Security benefits, of which up to 85 percent is included in MAGI depending on provisional income
Roth IRA conversions, which are treated as ordinary income in the year of conversion
Realized capital gains from investment account sales, including both short-term and long-term gains
Dividends from taxable investment accounts
Rental income from inherited or owned property
Post Oak Private Wealth Advisors integrates IRMAA planning in retirement into multi-year income projections to give retirees visibility into how each income source interacts with the surcharge thresholds across the full retirement horizon. See who we work with.
The Two-Year Lookback: The Feature That Creates Planning Urgency
The most consequential and least understood feature of IRMAA planning in retirement is the two-year lookback. Medicare premiums in any given year are based on MAGI reported to the IRS two years earlier. This means that income decisions made today have a specific, quantifiable Medicare premium consequence two years from now.
How this lookback creates specific planning urgency across the retirement timeline:
A large RSU vest, severance payment, or NQDC lump sum distribution in the retirement year, at age 62 for example, will determine Medicare premiums at age 64, when Medicare is not yet active, but the lookback is already running.
The income in the two years before RMDs begin, typically ages 71 and 72, determines Medicare premiums at ages 73 and 74, the years when required distributions begin adding to the income stack. Managing MAGI in those two pre-RMD years can moderate the Medicare cost that arrives simultaneously with the new RMD obligation.
The practical consequence of the two-year lookback is that retirement year income management is not only about the year itself. An avoidable income spike in year one of retirement, a lump-sum NQDC election that could have been structured as installments, or a Roth conversion sized without modeling the IRMAA tier, can add $8,000 to $12,000 in Medicare surcharges over the following two years.
The Income Events That Most Frequently Trigger IRMAA Surcharges
IRMAA planning in retirement focuses on identifying the income events with the largest impact on MAGI and understanding when they can and cannot be influenced.
Lump-sum NQDC distributions. An executive who elected a lump-sum payment from a deferred compensation plan at separation from service may receive $500,000 to $1 million or more as ordinary income in a single year. This is the most common single-year income spike that pushes retirees into the highest IRMAA tiers. It is also the event most difficult to modify after the fact, since NQDC distribution elections are irrevocable under IRC Section 409A and cannot be changed once made.
Required minimum distributions. RMDs from traditional IRAs begin at age 73 and grow each year as a percentage of the account balance. For retirees with large IRA balances, RMDs can add $50,000 to $150,000 or more in ordinary income annually, on top of all other income sources. This stacking effect frequently causes retirees to reach IRMAA tiers they were not in before RMDs began.
Roth conversions. Deliberate Roth conversion activity adds ordinary income in the year of conversion. The conversion is taxed at the applicable marginal rate and increases MAGI. IRMAA planning in retirement that includes Roth conversions must size each conversion against both the applicable tax bracket and the IRMAA tier boundary simultaneously.
Pension and Social Security income. These sources are generally fixed and not subject to timing control, but they establish the income floor above which all other sources stack. For retirees whose pension income alone is near an IRMAA threshold, any discretionary income from conversions, distributions, or capital events carries a higher marginal IRMAA cost.
How IRMAA Interacts With Roth Conversion Sizing
IRMAA planning in retirement is particularly relevant for retirees executing Roth conversions, because every dollar of conversion adds to MAGI and potentially crosses a surcharge tier boundary.
The IRMAA thresholds create natural checkpoints in the conversion sizing decision. For a married couple with total income before any conversion near $240,000, converting $20,000 may keep them within the second IRMAA tier. Converting $30,000 might push them into the third tier, adding $2,496 per couple in annual Medicare surcharges for the following two years, a total additional cost of approximately $4,992 over two years.
Whether crossing that tier is worth the cost depends on the tax math: if the conversion produces long-term tax savings from moving assets from the taxable ordinary income environment of the traditional IRA to the tax-free Roth, and if that savings exceeds the two-year Medicare premium increase, converting may still be the better financial outcome.
How Roth Distributions Can Moderate IRMAA Exposure
IRMAA planning in retirement has a specific and often underused tool: the Roth IRA distribution. Because qualified Roth distributions are not included in MAGI, they can fund spending needs without contributing to the income calculation that determines Medicare premium costs.
For a retiree whose MAGI from pension, Social Security, and required distributions lands just above an IRMAA tier boundary, substituting a Roth distribution for what would otherwise be an additional IRA withdrawal or taxable account sale can reduce MAGI below the tier threshold. The spending is maintained. The income is not added to the IRMAA calculation. The Medicare premium for the following two years reflects the lower, pre-substitution income.
This substitution strategy is most available to retirees who have built a meaningful Roth balance through years of Roth contributions or pre-retirement Roth conversions. For retirees with limited Roth assets, the tool exists but cannot be deployed at the scale required to make a material difference.
Building IRMAA Into the Multi-Year Income Projection
IRMAA planning in retirement is most useful when it is part of a multi-year income projection rather than a single-year calculation. Because the surcharge is based on income from two years prior, the relevant planning question in any given year is not just what IRMAA tier the current year's income produces, but what tier will result from this year's income when it becomes the lookback year two years from now.
A year-by-year income map that shows projected MAGI alongside the applicable IRMAA tier for each year of retirement, adjusted for the two-year lag, gives the retiree and their advisors visibility into the Medicare premium trajectory. It reveals the years where income is likely to spike due to NQDC distributions concluding, Social Security activating, or RMDs beginning, and it identifies the years where MAGI is likely to be lower and where substitution strategies or appeals may be available.
If you want to evaluate IRMAA planning in retirement within the context of your full income picture, including projected RMDs, Roth conversion activity, and the timing of other income sources, Post Oak Private Wealth Advisors can build that multi-year projection as part of a coordinated tax and income strategy. Talk to our team.
FAQ
What is IRMAA and how does it affect Medicare premiums in retirement?
IRMAA is the Income-Related Monthly Adjustment Amount, a surcharge applied on top of standard Medicare Part B and Part D premiums for beneficiaries whose income exceeds specified thresholds. The surcharge is assessed by the Social Security Administration based on modified adjusted gross income from two years prior. Standard Part B premiums in 2024 are approximately $174.70 per month per person; IRMAA surcharges can push that to as high as approximately $594.00 per month per person at the highest income tier.
What counts as income for IRMAA purposes?
For IRMAA purposes, income is modified adjusted gross income, which equals adjusted gross income plus tax-exempt interest such as municipal bond interest. Income sources that count toward MAGI include traditional IRA distributions, 401(k) withdrawals, pension income, Social Security benefits up to 85 percent, deferred compensation distributions, Roth conversions, realized capital gains, and dividends.
How does the two-year lookback affect IRMAA planning in retirement?
The two-year lookback means Medicare premiums in any given year are based on MAGI from two years earlier. A large income event in the retirement year determines Medicare costs two years later. A Roth conversion or large capital gain in year three of retirement determines premiums in year five. IRMAA planning in retirement accounts for this lag by modeling income decisions today against their Medicare premium consequences two years forward.
How do Roth conversions interact with IRMAA thresholds?
Roth conversions add to MAGI in the year of conversion and can push income across IRMAA tier boundaries, increasing Medicare premiums for the following two years. Whether the Medicare cost is justified depends on whether the long-term tax savings from the conversion exceed the two-year premium increase. The calculation must be done explicitly for each planned conversion, not assumed.
Can IRMAA be appealed or reduced if income was unusually high in the lookback year?
Yes. The Social Security Administration allows IRMAA reconsideration based on a life-changing event that reduced income since the lookback year. Qualifying events include retirement, loss of employment, death of a spouse, divorce, loss of pension income, or employer settlement payment. Retirement itself qualifies as cessation of work. The appeal is made using Form SSA-44 with documentation of the income change.
How do Qualified Charitable Distributions help with IRMAA Planning in Retirement?
QCDs allow IRA owners who are at least age 70½ to transfer up to $105,000 per year (2024 figure) directly from a traditional IRA to a qualifying charity. The distribution satisfies part or all of the annual RMD requirement, but unlike a standard distribution, the amount is not included in MAGI. For retirees whose MAGI is near an IRMAA tier boundary and who have charitable goals, using a QCD rather than taking the RMD as taxable income and donating cash can reduce MAGI, potentially avoiding a tier increase and its associated two-year-forward Medicare premium impact.