The IRMAA Risk at $100K Retirement Income
IRMAA (Income-Related Monthly Adjustment Amount) increases Medicare Part B and Part D premiums for retirees with MAGI above $106,000 single ($212,000 married) in 2025. For a retiree with $100,000 income a large RMD easily crosses this threshold — adding $576-$3,456/year in additional Medicare premiums depending on income level.
2025 IRMAA tiers for Medicare Part B (single filer)
| MAGI (Single) | Standard Part B Monthly | IRMAA Surcharge | Total Monthly | Annual IRMAA Cost |
|---|---|---|---|---|
| Under $106,000 | $174.70 | $0 | $174.70 | $0 |
| $106,000–$133,000 | $174.70 | $69.90 | $244.60 | $838.80 |
| $133,000–$167,000 | $174.70 | $174.70 | $349.40 | $2,096.40 |
| $167,000–$200,000 | $174.70 | $279.50 | $454.20 | $3,354 |
| $200,000–$500,000 | $174.70 | $384.30 | $559 | $4,611.60 |
RMD Planning at $100K Income Level
Margaret Foster in Scottsdale has $100,000 retirement income (Social Security $28K, pension $45K, investment income $27K) and a $1.2 million traditional IRA. Her age-73 RMD is $45,283 — likely pushing her MAGI above $130,000 and triggering the first IRMAA tier. The combined tax impact: 24% on the RMD plus $838/year in IRMAA.
Medicare uses your income from 2 years prior to determine IRMAA. Your 2027 Medicare premiums are based on 2025 income. A large 2025 RMD creates higher 2027 Medicare costs. This two-year lag means RMD income management requires planning 2+ years in advance.
RMD strategy impact on IRMAA at $100K income level
| RMD Strategy | RMD Taxable | MAGI | IRMAA Tier | Combined Tax Impact |
|---|---|---|---|---|
| No planning | $45,283 | $145,283 | Tier 2 ($174.70 surcharge) | 24% + $2,096/yr IRMAA |
| $10,000 QCD | $35,283 taxable | $135,283 | Tier 2 ($174.70 surcharge) | 24% + $2,096/yr IRMAA |
| $25,000 QCD | $20,283 taxable | $120,283 | Tier 1 ($69.90 surcharge) | 24% + $838/yr IRMAA (saves $1,258) |
| Large QCD or conversion (pre-RMD) | Reduced RMD | Under $106,000 | No IRMAA | Saves $2,096+/yr IRMAA |
Pre-RMD Roth Conversion Strategy at $100K
The most comprehensive strategy for a $100K income retiree approaching RMD start: perform Roth conversions in the 10 years before age 73 that stay within the 22%-24% bracket. Converting $50,000/year for 10 years reduces the IRA balance by approximately $500,000, cutting the age-73 RMD by $18,868 and potentially avoiding IRMAA triggers entirely.
- Pre-RMD Roth conversions reduce IRA balance and future RMD amounts permanently
- QCDs up to $105,000/year satisfy RMD while excluding the amount from income
- IRMAA planning: manage income to stay below IRMAA thresholds — each tier is worth thousands
- Consider Roth 401k if still working — employer contributions avoid future RMD accumulation
Model Your RMD + IRMAA Tax Impact at $100K
Enter your balance and income to calculate your full RMD tax burden including Medicare premium implications.