Conversion room
How much can you convert before each IRMAA threshold?
| Target | MAGI ceiling | Conversion room | Monthly premium |
|---|
2026 IRMAA, Roth conversion and RMD planner
Retirement Tax Cliff Calculator
Estimate how much Roth conversion or IRA withdrawal room you have before Medicare premiums, taxable Social Security, RMDs, and federal brackets start biting harder.
CMS 2026 IRMAA tables
IRS 2026 tax brackets
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Scenario view
See the pressure points before you move money
RMD projection
Required minimum distribution runway
| Year | Age | Projected RMD | Year-end balance |
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Methodology
Built for search intent, but backed by official tables
This calculator estimates IRMAA MAGI, taxable Social Security, federal tax, Roth conversion room, and RMD exposure using public 2026 figures. It is built as an educational planning tool, not tax, legal, investment, or Medicare advice.
IRMAA
Uses CMS and SSA 2026 Part B and Part D income-related monthly adjustment amount tables. IRMAA MAGI is modeled as AGI plus tax-exempt interest.
Federal tax
Uses IRS 2026 ordinary brackets, standard deductions, age 65 additions, and the temporary senior deduction phaseout. Qualified dividends and long-term gains are stacked after ordinary income.
Social Security
Uses the IRS Publication 915 style provisional income approach. Depending on filing status and income, up to 85 percent of benefits may be taxable.
RMDs
Uses the IRS Uniform Lifetime Table factors for a planning estimate. Beneficiary rules, first-year deferrals, inherited IRAs, QCDs, and plan-specific exceptions can change real outcomes.
Planning guides
Read the retirement tax cliff guides
Each guide answers one high-intent planning question with official IRS, CMS, or SSA source links, examples, and a natural next step back into the calculator.
FAQ
Retirement tax cliff questions
How does a Roth conversion trigger IRMAA?
A Roth conversion is taxable income. It can raise MAGI above a Medicare IRMAA threshold, which can increase Part B premiums and Part D surcharges after Medicare applies the two-year lookback.
What does "room before next IRMAA tier" mean?
It estimates the gap between your no-conversion IRMAA MAGI and the next official 2026 IRMAA threshold for your filing status. That gap is the rough amount of conversion room before the next tier.
Why can Social Security become taxable?
The IRS uses provisional income, which includes half of Social Security plus other income and tax-exempt interest. As provisional income rises, more benefits can become taxable, up to 85 percent.
Can I rely on this for filing taxes?
No. Use it as a planning estimate. Real returns can involve itemized deductions, state taxes, NIIT, QCDs, inherited IRA rules, first-year RMD timing, Medicare appeals, and other details.