A Roth conversion is one of the most powerful — and most misunderstood — moves in retirement planning. At its core it's simple: you take money sitting in a pre-tax account (a traditional IRA, 401(k), SEP-IRA, or similar) and move it into a Roth IRA, paying income tax on the converted amount today so you never owe tax on it again. The decision of whether to convert, and how much, depends entirely on your tax rate now versus your expected rate in retirement.
What changed in 2026
- Tax brackets are indexed for inflation, so the 2026 bracket thresholds shifted upward slightly — meaning a slightly larger conversion may still fit inside the 22 % or 24 % bracket before you cross into 32 %.
- Required Minimum Distribution (RMD) age is now 75 following the SECURE 2.0 changes, which lengthens the window between retirement and forced withdrawals — giving more runway for strategic conversions.
- State tax picture matters more than ever. A growing number of states exempt Roth distributions entirely; factor your state rate into the conversion math.
- The "backdoor" Roth remains viable for high earners who cannot contribute directly to a Roth IRA due to income limits.
How a Roth conversion works mechanically
- You direct your IRA custodian (or 401(k) plan, if allowed) to move a dollar amount from the traditional/pre-tax account to a Roth IRA.
- The moved amount is added to your gross income for that tax year.
- You pay ordinary income tax at your marginal rate on the converted sum.
- The money sits in the Roth, grows tax-free, and qualified withdrawals (after age 59½ and a 5-year hold) are completely tax-free.
No contribution limit applies to conversions. You can convert $5,000 or $500,000 — what constrains you is the tax bill you can absorb.
The tax cost in plain numbers
| Converted amount |
Marginal rate |
Approximate tax due |
| $10,000 |
22 % |
~$2,200 |
| $30,000 |
24 % |
~$7,200 |
| $50,000 |
32 % |
~$16,000 |
| $100,000 |
35 % |
~$35,000 |
These are simplified estimates. Your actual bill depends on your full income picture. Pay the tax from outside the IRA — paying it from the converted funds shrinks the Roth balance and reduces the long-run benefit.
When a Roth conversion makes sense
Low-income years. The conversion is taxed at your current rate. A year with a job gap, a leave of absence, large deductions, or a business loss is the ideal window.
Early retirement before Social Security. Many retirees have a "sweet spot" from age 60–70 when income is lower than it was while working and lower than it will be when RMDs + Social Security stack up.
Long time horizon. The tax-free compounding pays off most when you have 15–25 years for the converted assets to grow.
You expect higher future rates. If tax rates rise (a common planning assumption) or if your income will be higher in retirement, locking in today's rate is rational.
Estate planning. Roth IRAs pass to heirs income-tax-free; heirs can stretch withdrawals over 10 years with no tax on growth.
The partial-conversion strategy
Rather than converting everything at once, many planners recommend "bracket-filling" conversions:
- Estimate your total taxable income for the year.
- Find the top of your current bracket (e.g., the 22 % bracket ends at ~$100,525 for single filers in 2026 after inflation adjustments — confirm current IRS tables).
- Convert only enough to fill that bracket without crossing into the next.
- Repeat each year during your low-income window.
This spreads the tax hit over multiple years and avoids a single large bill that might push you into a higher bracket or trigger IRMAA surcharges on Medicare premiums.
Roth conversion vs. contributing directly
| Action |
Income limit applies? |
Tax effect |
| Direct Roth IRA contribution |
Yes (phaseout ~$150k–$165k single, 2026 est.) |
After-tax dollars in, no tax on growth |
| Roth conversion |
No limit |
Pay tax on converted amount now, no tax later |
| Backdoor Roth (contribute non-deductible, then convert) |
No limit |
Pro-rata rule applies if you have other IRA balances |
How to pick the right conversion amount
- Project your full-year income including wages, Social Security, dividends, and any other sources.
- Identify your marginal bracket and how much room remains before the next bracket.
- Convert up to that room — or less if the tax bill would be a hardship.
- Check for IRMAA triggers — if you are on Medicare or close to it, a large conversion can raise your Part B and Part D premiums two years later.
- Consult a fee-only financial planner for a multi-year conversion plan if your balances are significant.
Common mistakes
Converting in a high-income year. If you are still working at peak salary, converting often costs more in tax than the long-run benefit justifies. Run the numbers.
Paying the conversion tax from the IRA. Withholding 20–30 % from the converted amount costs you compounding on those dollars for decades. Pay from savings or a taxable account.
Ignoring the 5-year rule. Each conversion starts its own 5-year clock for penalty-free withdrawal of converted principal (before 59½). Plan accordingly.
Forgetting state taxes. Some states tax IRA withdrawals and Roth conversions; a few do not. Know your state's treatment before converting large amounts.
Not updating withholding or estimated taxes. A large conversion can trigger an underpayment penalty if you do not adjust your withholding or pay estimated quarterly taxes.
What to skip
- Converting everything in one year unless you are in an unusually low bracket and have abundant outside cash to pay the bill.
- Roth conversions when you are in the 32 %+ bracket with no near-term bracket drop expected — the math rarely favors it.
- Ignoring the backdoor route if you are a high earner with no pre-tax IRA balance — it avoids the income limit cleanly.
FAQ
Is there an income limit to do a Roth conversion?
No. Unlike direct Roth IRA contributions, conversions have no income ceiling. Anyone can convert regardless of income.
What happens if I change my mind after converting?
The TCJA (2017) eliminated "recharacterization" of conversions — you cannot undo a conversion. Think carefully before converting large amounts.
Do I need a Roth IRA open before converting?
Yes. Open one before you initiate the conversion; the receiving account must exist. There is no cost to open a Roth IRA at most major brokers.
How does a Roth conversion affect my Social Security benefits?
Converting adds to your MAGI in the conversion year, which can affect how much of your Social Security is taxable if you are already receiving it. Plan conversions before you start benefits when possible.
Where to go next
See What is a 401k match in 2026, What is vesting in 2026, and How to save for retirement if self-employed in 2026.