IRMAA: How Your Retirement Income Affects Medicare Premiums
You finally retire. The pension starts. Your TSP withdrawals kick in. Maybe you sell a house or start Social Security.
Then you open a letter from Medicare and think: “Why did my Medicare premiums go up?”
For many federal retirees, the answer is one four-letter word: IRMAA.
IRMAA can feel like a surprise tax on success. But it’s really a rule that raises your Medicare premiums when your retirement income (as shown on your tax return) goes over certain lines.
The good news: once you understand how IRMAA works—and how Medicare looks at your income—you can often plan around it. Or at least avoid the most common mistakes.
What IRMAA is (and why federal retirees run into it)
IRMAA stands for Income-Related Monthly Adjustment Amount. It’s an extra charge added to:
- Medicare Part B premiums (doctor visits, outpatient care)
- Medicare Part D premiums (prescription drug coverage)
If your income is above the IRMAA thresholds, you pay more than the standard premium.
This hits a lot of federal retirees because retirement often stacks multiple income streams at once:
- FERS pension (or CSRS pension)
- TSP withdrawals (especially large ones)
- Social Security
- Required withdrawals later (RMDs) from traditional accounts
- Capital gains (selling investments, a home, or a business)
- One-time events (inheritance distributions, Roth conversions)
Medicare doesn’t “guess” your income. It uses what’s on your tax return.
For the official overview, see CMS guidance on Medicare costs.
The key income number for IRMAA: MAGI (not your pension amount)
IRMAA is based on your Modified Adjusted Gross Income (MAGI) from your IRS tax return.
In plain English, MAGI for IRMAA is usually:
- Adjusted Gross Income (AGI)
plus - tax-exempt interest (like interest from many municipal bonds)
So even “tax-free” bond interest can increase IRMAA.
You can see how AGI is built on your tax return and learn more at IRS.gov.
Medicare uses a two-year lookback (this is the part that trips people)
Medicare usually looks at your income from two years ago.
Example: Your 2026 Medicare premiums typically use your 2024 tax return.
That means a one-time income spike—like a big TSP withdrawal—can raise your Medicare premiums later, even if your income drops again after that.
The income review and IRMAA process runs through Social Security. Helpful starting point: Social Security Medicare premium rules.
IRMAA thresholds: the lines that trigger higher Medicare premiums
IRMAA is based on filing status and income brackets. The exact numbers can change year to year.
Here’s the most important concept for planning:
IRMAA thresholds are “cliff” brackets
If you go $1 over a threshold, you can get bumped into the next bracket and pay higher Medicare premiums for the year.
That’s why smart planning often looks like: “How do I keep MAGI under the next line?”
For the current official brackets and premium amounts, always check:
How IRMAA changes your Medicare premiums (real-dollar examples)
To keep this useful, let’s use a simple example with round numbers.
Assume the standard Part B premium is about $175/month (this is close to recent years, but check the current amount on CMS).
When IRMAA applies, you pay:
- the standard Part B premium
- plus an extra IRMAA amount
- and a Part D IRMAA surcharge (even if your Part D plan premium is low)
Example: A single federal retiree with “normal” retirement income
Marsha is single. She has:
- FERS pension: $38,000/year
- Social Security: $24,000/year
- TSP withdrawals: $18,000/year
Rough total cash flow: $80,000/year (before tax rules and how Social Security is taxed).
She might stay under the first IRMAA threshold and pay the standard Medicare premiums.
Example: The “one big TSP withdrawal” problem
Now Marsha needs a new roof and helps a grandchild with college. She takes an extra $40,000 from her traditional TSP in one year.
That extra withdrawal increases her taxable income and could push her MAGI over an IRMAA threshold.
Result: Two years later, she may pay higher Part B and Part D premiums for the full year, even if she goes back to normal withdrawals.
This is why it helps to understand TSP withdrawal options and tax basics at TSP.gov.
Scenario angle: married federal retirees vs. widows/widowers (a big IRMAA trap)
IRMAA planning changes a lot based on filing status.
Married filing jointly can be more forgiving
Many IRMAA thresholds are higher for married couples filing jointly than for single filers. That can give couples more room for:
- Roth conversions
- big TSP withdrawals
- capital gains
The widow/widower “tax and IRMAA squeeze”
Here’s the painful reality: after a spouse dies, the survivor often goes from:
- Married filing jointly
to - Single
But their income may not drop much. In fact, it can stay high because the survivor may still have:
- the same TSP balance
- similar investment income
- and sometimes most of the pension income (depending on survivor elections)
So the survivor can hit IRMAA sooner, and pay higher Medicare premiums.
If you’re making survivor benefit choices, it’s worth reading up on federal retirement basics at OPM.gov and talking through the trade-offs.
Practical IRMAA examples with specific numbers (different people, different outcomes)
Below are “planning style” examples. These are not tax advice—just the kind of math that helps you see the moving parts.
Always confirm current premiums and brackets at CMS and your own MAGI with your tax pro or software.
Example 1: Single retiree near an IRMAA threshold
Derrick (single) expects MAGI around $102,000.
He is thinking about a $8,000 Roth conversion (moving money from traditional TSP/IRA to Roth, paying tax now).
If the first IRMAA threshold for singles is around $103,000 (example only), that conversion could push him over by $7,000.
If that bumps him into the next bracket, the real cost is not just income tax. It can also mean:
- higher Part B premiums (monthly)
- plus a Part D IRMAA surcharge (monthly)
Planning move: Derrick could convert $1,000 instead of $8,000 this year, and do more next year—staying under the line.
Example 2: Married couple selling a rental property
Lena and Chris (married) have steady retirement income:
- Combined pensions and Social Security: $140,000
- TSP withdrawals: $30,000
- MAGI around $170,000
Then they sell a rental and realize $120,000 in long-term capital gains.
Now MAGI could jump near $290,000.
Even though the sale is one-time, it can trigger IRMAA. Two years later they may pay higher Medicare premiums for the year.
Planning move: If they can control timing, they might sell in a year when their other income is lower (for example, before Social Security starts), or spread gains if possible (not always possible).
Example 3: Military retiree + federal retiree combo
Sam is a military retiree working a civilian federal job, then retires from federal service too.
Income sources:
- Military retired pay: $32,000
- FERS pension: $28,000
- Social Security: $26,000
- TSP withdrawals: $35,000
He’s at $121,000 before considering tax details.
Depending on filing status and other income, he may be in IRMAA territory.
For military retired pay info and tax statements, see DFAS. For broader military retirement topics, Military.com can be a helpful starting point (not official, but widely used).
Common IRMAA mistakes (and the misconceptions behind them)
“My pension is taxed, so Medicare is punishing me twice”
IRMAA isn’t a tax. It’s a premium adjustment based on income. It still feels like a penalty, but the rule is: higher income, higher Medicare premiums.
“I can appeal IRMAA because my income is lower now”
Sometimes yes—but only for certain life events.
Medicare/SSA allows appeals for major events like:
- retirement (work stoppage)
- death of a spouse
- divorce
- loss of pension income
- employer settlement
- other specific events
A big TSP withdrawal or a Roth conversion you chose usually isn’t considered a qualifying event.
Start here for the process: SSA Medicare IRMAA information.
“Tax-free municipal bond interest doesn’t count”
For IRMAA MAGI, tax-exempt interest often gets added back. So it can still raise your IRMAA.
“Part D doesn’t matter because my drug plan is cheap”
IRMAA can add a separate Part D surcharge even if your Part D plan premium is low.
“I’ll just take a huge withdrawal in December”
Timing matters, but not the way people think. A December withdrawal still counts for that tax year and can still increase MAGI and trigger IRMAA later.
How to estimate IRMAA before it hits you (simple DIY steps)
You don’t need fancy software to get a decent estimate.
Gather your income sources for the year
Make a list of expected amounts:
- FERS/CSRS pension (see OPM)
- Social Security (see SSA)
- TSP withdrawals (see TSP.gov)
- IRA withdrawals
- dividends/interest/capital gains
- any one-time events (home sale gain, Roth conversion, severance, etc.)
Estimate your MAGI
Your tax software can do this, but a rough check is:
- Start with expected AGI
- Add tax-exempt interest
If you’re close to a known IRMAA threshold, you’re in the “danger zone.”
Compare to current IRMAA thresholds
Use the official chart for the year you’re planning around:
Remember the two-year lookback. You’re planning today for premiums later.
How to lower IRMAA (or avoid crossing an IRMAA threshold)
You can’t always avoid IRMAA. And sometimes paying it is fine if the move is worth it (like a Roth conversion that helps long-term). But you should make it a choice, not a surprise.
Spread income across years when you can
Instead of one big withdrawal:
- take smaller TSP withdrawals over two tax years
- delay a large Roth conversion and do it in pieces
- coordinate big capital gains with lower-income years
Watch the “first year of retirement” spike
Many federal employees have a weird income year when they retire:
- part-year salary
- annual leave payout
- maybe a bonus
- plus pension starting later
- plus maybe starting Social Security
That year can be an IRMAA trigger.
Fed-focused retirement planning often gets covered well by outlets like Federal Times and GovExec (news sources, not official rules).
Think twice about large traditional TSP withdrawals before Medicare
A large traditional TSP withdrawal increases taxable income.
If you’re not on Medicare yet, a high-income year might not matter for IRMAA right away—but it can matter once you’re in the two-year lookback window.
For TSP rules and withdrawal options, stick with TSP.gov.
Consider Roth strategy carefully (pros and cons)
Roth conversions can reduce future RMDs and future taxable income, which may help later.
But the conversion itself increases MAGI now, which can trigger IRMAA later.
Sometimes the best move is a “partial conversion” that stays under the next IRMAA threshold.
Use the appeal process when a real life event applies
If you retired and your income dropped, you may be able to request a new IRMAA decision.
Start with Social Security’s IRMAA page and forms:
A quick how-to guide for federal retirees: IRMAA planning checklist
Before you retire (or in your last working year)
- Estimate whether your final working year will be a high MAGI year (leave payout can be big).
- If you’re doing a Roth conversion, consider doing it in earlier years when income is lower.
In early retirement (before RMDs)
- Map out a 5–10 year tax plan: pension + TSP + Social Security timing.
- Run “what if” numbers: What happens if you withdraw $20k more? What if you sell investments?
Each fall (before year-end)
- Check your projected MAGI.
- If you’re near an IRMAA threshold, decide whether to:
- reduce a withdrawal,
- delay income,
- harvest gains carefully,
- or accept IRMAA as the cost of the move.
When you get an IRMAA letter
- Compare the income year Medicare used to your tax return.
- If you had a qualifying life event (like retirement), consider an appeal through SSA:
Bottom line: Key takeaways on IRMAA and Medicare premiums
- IRMAA is an income-based add-on to Medicare premiums (Part B and Part D).
- Medicare usually uses a two-year lookback, so today’s retirement income choices can raise premiums later.
- The biggest planning tool is knowing the IRMAA thresholds and avoiding “$1 over the line” moments when you can.
- One-time income events—big TSP withdrawals, Roth conversions, capital gains—often create surprise IRMAA.
- Some people can reduce or remove IRMAA using the SSA appeal process after certain life events (like retirement), but not every income spike qualifies.
- For official rules and current premium charts, stick with CMS, SSA, and IRS.gov.
If you want to go deeper on how federal benefits fit together, check our benefits guide and federal pay info.