Who: U.S. retirees and near-retirees with IRAs, 401(k)s, taxable investments, rental property or planned Roth conversions.
What: Eleven specific financial moves that commonly raise your Modified Adjusted Gross Income (MAGI), trigger higher Medicare IRMAA surcharges or increase the portion of Social Security that’s taxable — and what to do about them today.
When: Updated for July 2026 with fresh field observations, regulatory reminders and concrete action items.
Where: For taxpayers subject to U.S. federal tax, Medicare and Social Security rules.
Why it matters: Because the Social Security Administration still uses a two‑year MAGI lookback to set IRMAA, SECURE 2.0 shifted Required Minimum Distribution (RMD) timing, and recent market and life-event sequencing is concentrating taxable events into fewer years. Small moves this year can raise costs for multiple years.
Context: what’s changed since June 2026 — and why July matters
The legal mechanics remain the same, but patterns have shifted. SECURE 2.0 (enacted March 2022) raised the RMD start age to 73 for most people beginning in 2023 — that delay reduced near-term taxable withdrawals but has concentrated larger RMDs into later years. Meanwhile, the Social Security Administration continues to set IRMAA (Income‑Related Monthly Adjustment Amount) using your MAGI from two years earlier, so calendar-year spikes show up with a lag.
Two regulatory facts to keep top of mind:
- IRMAA lookback: Your MAGI from two years prior is what the SSA uses when it sets Part B and D surcharges. Practically: a large taxable event in 2024 typically affects 2026 premiums.
- Missed-RMD penalty relief: SECURE 2.0 reduced the excise tax for missed RMDs from 50% to 25%, and to 10% if corrected timely in many cases; you still must act fast if you miss one.
11 stealth tax triggers retirees keep tripping (July 2026 update)
1) Accidentally tripping IRMAA with an otherwise “normal” move
An otherwise sensible Roth conversion, capital gain or severance payment can push your MAGI over an IRMAA cliff and raise Medicare premiums for the following two years. In July 2026 the lesson hasn’t changed: run the two‑year lookback before any large taxable event.
Do this now: Run a two‑year MAGI projection. If you’re near a threshold, split the transaction across calendar years, use tax‑loss harvesting, or delay taxable events until a lower‑income year.
2) Underestimating the “tax on tax” from Social Security’s provisional income
When provisional income (AGI plus tax‑free interest plus half of Social Security) crosses statutory thresholds, up to 85% of benefits can become taxable. That makes an IRA withdrawal more costly in practical terms than the marginal tax rate suggests.
Do this now: Model claiming age with your withdrawal plan. If delaying benefits reduces provisional income and total lifetime tax, it’s worth considering.
3) The RMD avalanche after years of deferring
Delaying RMDs reduces near‑term taxes but concentrates larger required payouts later, especially if accounts grew in 2023–2025. Those concentrated RMDs can create multi‑year MAGI spikes and IRMAA consequences.
Do this now: Use modest Roth conversions or partial distributions in lower-income windows to smooth future RMDs.
4) Converting to Roth without planning for IRMAA
Roth conversions permanently remove future tax exposure but create taxable income in the conversion year that counts for IRMAA and provisional income.
Do this now: Set a conversion cap tied to a marginal-tax target and IRMAA cliff levels on your two‑year lookahead. Convert over multiple years rather than all at once.
5) Taking distributions in the wrong order
Spending taxable‑account gains first or emptying tax‑deferred accounts without sequencing can push you into phaseouts and higher Medicare surcharges.
Do this now: Build a three‑bucket withdrawal plan (taxable, tax‑deferred, Roth) and test sequencing scenarios for both current and projected MAGI.
6) Selling a rental or concentrated stock position “all at once”
Large, single‑year gains spike MAGI. Where possible, plan multi‑year sales, consider installment sales, or donate appreciated shares to reduce immediate MAGI.
Do this now: If you’ve got a big disposition planned, ask your adviser to map its IRMAA and provisional‑income impact over the next three years.
7) Missing the obvious: use Qualified Charitable Distributions (QCDs)
QCDs up to $100,000 per year (individuals age 70½ or older) exclude those amounts from AGI and therefore lower MAGI. That still works in 2026 and is one of the simplest IRMAA‑aware moves.
Do this now: If you itemize charity or plan gifts, route them as QCDs from an IRA rather than donating after taking distributions.
8) Confusing taxable income, MAGI and provisional income
Medicare and Social Security use different income measures than the IRS tax‑bracket tables. Tracking only “taxable income” leaves blind spots.
Do this now: Track three figures annually: taxable income on the return, MAGI (for IRMAA), and provisional income (for Social Security taxation). Demand to see all three in your advisor’s model.
9) Underwithholding on lumpy retirement income
IRA withdrawals, capital gains and one‑time severance payments can leave you underpaid for estimated tax purposes and subject to penalties.
Do this now: Use withholding on IRA distributions or make quarterly estimated payments timed to realization events.
10) Treating HSA strategy as an afterthought
HSAs remain a tax‑efficient medical funding vehicle. Paying current medical costs out of pocket and reimbursing from the HSA later preserves tax‑advantaged growth without raising MAGI.
Do this now: Keep receipts, maintain a written reimbursement schedule, and preserve HSA balances where possible.
11) Failing to stress‑test the surviving spouse squeeze
After a spouse’s death, household income can stay the same while filing status shifts to single, often producing higher tax and IRMAA exposure for the survivor.
Do this now: Run a survivor projection, consider limited Roth conversions while both spouses are alive, and review life‑insurance timing to plug taxable income gaps.
Impact: who this hits and how much it can cost
Anyone with mixed account types and MAGI near phaseout bands is at risk: married couples, landlords selling property, people planning Roth conversion windows, and survivors. Concrete costs vary by bracket and benefit amounts, but IRMAA surcharges commonly add hundreds per month to Medicare premiums and a shift from 20% to 85% taxable Social Security can change taxable income by thousands annually. The takeaway: timing and sequencing matter more than a single-year marginal rate.
Reactions from the field (July 2026)
Retirement planners I spoke with in June and July 2026 report more clients surprised by IRMAA impacts tied to 2023–2025 account growth and delayed RMDs. Custodians and advisors say the most common mistakes are aggregating gains into one calendar year and failing to model provisional income when clients are near Social Security phaseouts.
"Model the three income numbers and watch the two‑year lookback — most mistakes are planning oversights, not intent," says a fee‑only retirement tax specialist in Boston (who asked to remain unnamed to speak candidly about client trends).
What’s next — immediate actions for July 2026
- Pull your federal returns for 2022–2025 and estimate MAGI for 2026–2027; identify cliff risks.
- If you expect a large gain this year, consult a CPA or tax‑specialist and consider multi‑year sales, installment sales, or QCDs.
- Set a yearly Roth conversion ceiling tied to both a marginal‑tax target and IRMAA thresholds on your two‑year lookahead.
- If you missed an RMD, correct it immediately with the plan custodian and file IRS Form 5329 only after consulting your adviser; SECURE 2.0’s relief may apply.
- If you get an IRMAA notice you believe is wrong due to a life‑changing event, file SSA Form SSA‑44 to request reconsideration and gather supporting documents.
Your rights
You have the right to detailed, itemized MAGI and provisional‑income projections from any paid adviser. You have the right to appeal an IRMAA determination using SSA Form SSA‑44 if your income change resulted from a qualifying life‑changing event (marriage, divorce, death of a spouse, loss of pension or work‑related income reduction). If you missed an RMD, you may be eligible for penalty relief under SECURE 2.0 if corrected quickly — speak to your custodian and tax counsel immediately.
Next steps (what you can do this week)
- Gather federal returns for the past four years and estimate expected MAGI for the next two years.
- List planned large transactions and ask an advisor to model MAGI, provisional income and IRMAA effects across those years.
- If you make charitable gifts, consider QCDs up to $100,000 if eligible.
- Schedule a 60‑minute call with a CPA or CFP specializing in retirement taxes and bring your multi‑year MAGI projection.
FAQ
How does IRMAA get calculated and when will it affect my premiums?
The Social Security Administration calculates IRMAA using your Modified Adjusted Gross Income (MAGI) from two years earlier. For example, your 2024 MAGI typically determines your Medicare Part B and D surcharges for 2026. If a life‑changing event reduced your income, you can file SSA Form SSA‑44 to request reconsideration with supporting documents.
Can a Qualified Charitable Distribution (QCD) reduce my Medicare premiums?
Yes. QCDs of up to $100,000 per year (from IRAs for owners age 70½ or older) are excluded from AGI and therefore lower MAGI used for IRMAA. To count, the gift must be transferred directly from the IRA custodian to the qualifying charity.
What if I missed an RMD?
Correct the missed distribution with your custodian immediately. File IRS Form 5329 only after consulting your adviser; under SECURE 2.0 the excise tax for missed RMDs was reduced (from 50% to 25% and to 10% if corrected promptly in many cases). Timely correction and documentation improve chances for penalty relief.
Should I stop Roth conversions because of IRMAA?
No. Roth conversions remain a powerful tool to reduce future RMDs and taxable income. But do them strategically: cap conversions to avoid IRMAA cliffs, spread them over years, and run multi‑year simulations before acting.
Who should I hire to help with this?
Hire a CPA or fee‑only CFP with documented experience in retirement tax planning. Ask for sample projections showing taxable income, MAGI and provisional income across at least three years. If you pay for advice, you have the right to clear, itemized projections.
Bottom line: As of July 2026, retirement tax planning remains about the shape of income across years, not just a single tax year. Run a two‑year MAGI lookahead before any large move, sequence transactions to avoid cliffs, and consult a qualified advisor this week if you’re near a threshold. Your rights include appealing IRMAA decisions (SSA‑44) and requesting RMD penalty relief; use them if necessary.