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A Roth IRA conversion moves retirement money from a pre-tax account into a Roth IRA. You generally pay income tax on the pre-tax amount converted now, while future qualified Roth IRA withdrawals can be tax-free.
The important question is not simply whether tax rates will rise. It is whether paying tax on those retirement dollars today is likely to produce a better after-tax result than leaving them pre-tax and paying tax when you withdraw them later.
There is no income limit for Roth conversions and no annual dollar cap on how much you can convert. But a larger conversion can push more income into higher tax brackets and affect other income-based costs.
Key takeaways
- Pre-tax amounts converted to a Roth IRA are generally taxable in the year of conversion.
- There is no annual Roth conversion limit, but converted dollars can span multiple tax brackets.
- Partial conversions can help you manage the tax bill instead of converting an entire account at once.
- The pro-rata rule, Roth five-year rules, ACA subsidies, Medicare IRMAA, and state taxes can all affect the real cost of a conversion.
Roth conversion vs. backdoor Roth IRA
A Roth conversion and a backdoor Roth IRA both involve moving money into a Roth IRA, but they solve different problems.
| Feature | Roth conversion | Backdoor Roth IRA |
|---|---|---|
| What it does | Moves existing retirement money into Roth | Uses a nondeductible Traditional IRA contribution followed by a conversion |
| Conversion limit | No annual dollar cap | No conversion cap, but the contribution limit still applies |
| 2026 IRA contribution limit | Not applicable to converted money | $7,500, or $8,600 if age 50+ |
| Tax impact | Pre-tax amounts converted are generally taxable | Often little conversion tax if there are no other pre-tax IRA balances and little or no gain before conversion |
| Common use | Moving existing pre-tax retirement savings to Roth | Getting new money into Roth when direct contributions are restricted |
For 2026, the IRA contribution limit is $7,500, or $8,600 if you qualify for the age-50 catch-up contribution.
If income prevents you from contributing directly to a Roth IRA, see our backdoor Roth IRA guide.
How Roth conversion taxes work
A taxable Roth conversion is generally added to your income for the year.
Suppose a single filer earns $75,000 in wages and makes a $25,000 fully taxable conversion.
In a simplified example:
- Wages: $75,000
- Roth conversion: $25,000
- Income before deductions: about $100,000
If the taxpayer takes the 2026 standard deduction of $16,100 and has no other relevant adjustments or deductions, taxable income would be roughly $83,900.
The conversion is not necessarily taxed entirely at one rate.
Federal income tax is progressive, so converted dollars sit on top of your other taxable income and may fall into more than one tax bracket.
For example, the 22% federal bracket for a single filer in 2026 applies to taxable income above $50,400 through $105,700.
That is why it is more useful to estimate the additional tax created by the conversion than to simply multiply the conversion amount by your current marginal rate.
Paying the tax
If possible, paying the conversion tax with money outside the retirement account keeps more money invested inside the Roth.
Using retirement money to cover the tax reduces the amount that reaches the Roth. If you are under 59½, amounts distributed rather than converted may also face a 10% additional tax unless an exception applies.
A conversion can also increase the amount of tax you need to pay during the year, so you may need to adjust withholding or make estimated tax payments.
How much should you convert?
Roth vs Traditional IRA Calculator
One common approach is bracket filling: converting enough to use some or all of a target tax bracket without automatically moving a large amount into the next bracket.
Suppose a single filer has $70,000 of taxable income before a conversion in 2026.
The 22% bracket ends at $105,700, leaving:
$105,700 – $70,000 = $35,700
of room before the 24% bracket begins.
If that person makes a fully taxable $25,000 conversion:
- Taxable income rises to $95,000
- The conversion remains within the 22% bracket
- Estimated additional federal income tax is about $5,500
That does not mean $25,000 is the optimal conversion. It only shows how bracket room can be used when planning a partial conversion.
Bracket-filling conversion calculator
Use the calculator to estimate how much additional taxable income may fit within a selected 2026 federal tax bracket.
Treat the result as a planning estimate, not a recommendation. It does not account for every deduction, credit, state tax, ACA premium tax credit, Medicare IRMAA threshold, Social Security interaction, or other tax rule that could affect your actual conversion cost.
When can a Roth conversion make sense?
A conversion is often worth evaluating when your tax situation is temporarily different from normal.
You have a lower-income year. A job transition, sabbatical, business-income decline, or early retirement can leave more room in lower tax brackets.
You expect the converted dollars to face a higher tax rate later. Future pensions, RMDs, Social Security, or other retirement income could increase the marginal rate on future Traditional IRA withdrawals.
You want to reduce future RMDs. Converting reduces your pre-tax retirement balance. Traditional IRAs eventually become subject to required minimum distributions, with the applicable starting age depending on birth year. Roth IRA owners generally do not have lifetime RMDs.
You have a long investment horizon. Assets moved to Roth have more time to potentially grow before retirement, although investment returns are never guaranteed.
Market values have fallen. If a conversion already fits your tax plan, lower asset values may let you convert more shares for the same taxable dollar amount. A market decline by itself is not a reason to convert.
When should you be careful?
The federal tax bracket is only part of the conversion decision.
A conversion deserves additional scrutiny if it would push substantial income into a rate you expect to avoid later or if you do not have enough outside cash to comfortably cover the tax.
There are also several less obvious effects:
- ACA Marketplace coverage: A taxable conversion increases income and can reduce premium tax credits.
- Medicare: A large conversion can increase MAGI and potentially trigger higher Part B and Part D premiums through IRMAA. Medicare generally looks at income from two years earlier.
- Social Security: Additional income can increase the taxable portion of Social Security benefits.
- State taxes: The same conversion can have a different total cost depending on where you live.
- Early withdrawals: If you expect to use converted money before age 59½, the Roth five-year rules require extra attention.
This is why a conversion that looks attractive based only on a federal bracket can become less appealing after the other effects are included.
The pro-rata rule
The pro-rata rule is especially important if you have made nondeductible Traditional IRA contributions while also holding pre-tax IRA money.
Suppose you have:
- $90,000 of pre-tax IRA money
- $10,000 of nondeductible basis
- $100,000 total
Only 10% of the combined balance represents after-tax money.
If you convert $10,000, you cannot simply designate the conversion as the $10,000 of after-tax money. In this simplified example, approximately $9,000 would be taxable and $1,000 would represent previously taxed basis.
The calculation generally considers Traditional, SEP, and SIMPLE IRA balances together rather than treating each IRA separately.
Conversions from these IRAs to Roth IRAs are generally reported on Form 8606, which is also used to track nondeductible IRA basis.
One possible workaround
If your employer’s 401(k) accepts incoming rollovers, you may be able to move eligible pre-tax IRA money into the plan while leaving nondeductible basis in the IRA.
That can reduce the pro-rata problem for a later conversion, but not every employer plan accepts incoming rollovers. Compare the plan’s rules, fees, and investment options before using this strategy.
The Roth IRA five-year rules
There are two different five-year concepts that commonly cause confusion.
The first applies to qualified Roth IRA distributions. The Roth IRA must satisfy the five-tax-year requirement, and another qualifying condition generally must apply, such as reaching age 59½, before earnings can be withdrawn as part of a qualified distribution.
The second applies to conversions. Each conversion can have its own five-tax-year period for determining whether the 10% additional tax applies to certain withdrawals of taxable converted amounts before age 59½.
Roth IRA ordering rules also matter. Distributions are generally treated as coming from regular contributions first, followed by conversion amounts and then earnings.
If you plan to leave the Roth untouched for retirement, these rules may be less important in practice. They matter much more when Roth conversions are part of an early-retirement withdrawal strategy.
How to do a Roth conversion
The process itself is usually simpler than the tax planning.
- Estimate your taxable income. Include other income and deductions rather than looking only at salary.
- Choose a conversion amount. Consider federal and state taxes plus ACA, Medicare, and Social Security effects where relevant.
- Set up the receiving Roth IRA. You can use an existing Roth IRA or open one with a provider that supports conversions.
- Request the conversion or rollover. Traditional and SEP IRA assets can generally be converted directly. Eligible employer-plan money may also be rolled directly to a Roth IRA, so a Traditional IRA is not always required as an intermediate step.
- Plan for taxes and check the investment. Make sure you can cover the tax and verify how the converted assets are invested after the transaction settles.
A SIMPLE IRA has an additional restriction. During the two-year period beginning when you first participate in the SIMPLE IRA plan, you generally cannot convert or roll that money to a Roth IRA. Broader rollover and conversion options generally become available after that period.
Your custodian will generally issue Form 1099-R for a reportable distribution. IRA conversions are generally reported on Form 8606, while employer-plan rollovers can involve different reporting.
Frequently asked questions
Is there an income limit on Roth IRA conversions?
No. Income limits on direct Roth IRA contributions do not prevent Roth conversions.
For 2026, the direct Roth contribution phase-out range is $153,000 to $168,000 for single and head-of-household filers and $242,000 to $252,000 for married couples filing jointly.
There is also no annual dollar cap on Roth conversions.
Can I undo a Roth conversion?
Generally, no. Roth conversions made under current law cannot be recharacterized back into a Traditional IRA, so estimate the tax impact before completing the transaction.
Should I convert if I am in the 22% bracket?
Being in the 22% bracket does not automatically make a conversion worthwhile.
Compare the marginal tax cost today with the likely tax treatment of those dollars later, while also considering state taxes, future RMDs, ACA or Medicare effects, Social Security, and how you will pay the conversion tax.
Can I convert a 401(k) directly to a Roth IRA?
An eligible distribution from a Traditional 401(k) or another qualifying employer plan may be rolled directly to a Roth IRA. You do not necessarily have to roll it into a Traditional IRA first.
Your plan’s distribution and rollover rules still apply.
What is the best year for a Roth conversion?
There is no universally best year.
Lower-income years are often worth evaluating because more of the conversion may fit into lower tax brackets. Early retirement, a career break, or an unusually low-income year can create such a window.
Bottom line
A Roth IRA conversion is ultimately a tax-timing decision.
The goal is not simply to pay tax now instead of later. It is to determine whether paying tax on specific retirement dollars today is likely to produce a better after-tax outcome than leaving them pre-tax.
Partial conversions can be useful when you have room in a target tax bracket, especially during lower-income years. But federal brackets are only part of the calculation. ACA subsidies, Medicare IRMAA, Social Security, state taxes, future RMDs, and the cash available to pay the tax can all change the result.
For related planning, see our backdoor Roth IRA guide, Roth conversion ladder guide, and 401(k) rollover guide.
Tax consequences depend on your individual circumstances. For a large conversion, consider reviewing the transaction with a qualified tax professional before executing it.
