Short answer: IRMAA is not a smooth percentage. Medicare uses income ranges. Cross into the next range and the surcharge changes to that tier.
Why the cliff matters
A small amount of extra Medicare MAGI can create a larger premium change than people expect. This is especially important before year-end Roth conversions, IRA withdrawals, capital gains, or one-time consulting income.
Do not stop just over a bracket
If a plan intentionally crosses a threshold, the better question may be whether the extra income is worth the full surcharge. Sometimes the answer is no. Sometimes the answer is yes because the conversion or withdrawal accomplishes a bigger tax goal. The mistake is crossing the line by accident.
Education sponsor placement for bracket planning tools, retirement income software, or advisor-client resources.
Cliff planning checklist
- Estimate Medicare MAGI before executing a large income event.
- Find the next bracket, not just the current bracket.
- Leave a margin for dividends, interest, fund distributions, or tax-exempt interest.
- Use the calculator again after tax documents are clearer.
Common cliff events
Roth conversions, RMDs, taxable IRA withdrawals, taxable stock sales, home sale gains, and tax-exempt municipal bond interest are common reasons people unexpectedly cross a threshold.
Next step: estimate your surcharge and use the IRMAA planning checklist before the income event.