Quick Answer
Before doing a Roth conversion, estimate your current tax bracket, next tax bracket, IRMAA tier, taxable Social Security impact, future RMD exposure, state taxes, and how you will pay the tax. A conversion is strongest when it fills a low-tax year without creating avoidable premium or cash-flow problems.
1. Start With The Purpose
Do not convert just because Roth accounts sound attractive. A conversion should solve a specific problem: lowering future RMDs, using a temporarily low bracket, improving surviving-spouse flexibility, reducing taxable estate exposure, or creating tax-free assets for later spending.
2. Estimate Base Income First
Before adding a conversion, estimate income that already exists: wages, pension, Social Security, interest, dividends, capital gains, rental or business income, and existing IRA withdrawals. The conversion stacks on top of that income.
3. Check Federal Tax Brackets
The IRS 2026 inflation adjustments include updated tax brackets and standard deductions. A common strategy is to convert enough to fill a target bracket, but not so much that the next bracket or another cliff changes the result.
4. Check IRMAA
If you are on Medicare or close to Medicare age, estimate IRMAA MAGI. A conversion that looks fine for federal tax can still raise Medicare premiums in a future year. The important number is room before the next threshold.
5. Check Social Security Taxation
If you receive Social Security, a conversion may cause more benefits to become taxable. This can raise the effective tax rate during the phase-in range. The effect is not obvious unless you calculate it.
6. Project RMDs
Large pre-tax balances can create future required withdrawals. Estimate RMDs before deciding that today's conversion cost is too high. Sometimes paying some tax now reduces a larger forced-income problem later.
7. Decide How To Pay The Tax
Many planners prefer paying conversion tax from cash or taxable assets rather than withholding from the converted retirement account. Using retirement assets to pay the tax can reduce how much actually reaches the Roth account.
8. Watch State Taxes And ACA Credits
This calculator focuses on federal tax, IRMAA, Social Security, and RMD planning. State taxes, Affordable Care Act subsidies, net investment income tax, and other rules may matter. A tax professional can help model those items before you execute a large conversion.
Pre-Conversion Checklist
- What is my no-conversion MAGI?
- What federal bracket am I trying to fill?
- Will this cross an IRMAA threshold?
- Will more Social Security become taxable?
- How much future RMD pressure am I reducing?
- Can I pay the tax without disrupting my cash reserve?
- Does the surviving spouse scenario change the answer?
- Have I reviewed state tax and professional advice?
Next step: Run the checklist through the calculator with several conversion amounts.
Test conversion amounts