Quick Answer
A Roth conversion moves money from a Traditional IRA to a Roth IRA. You pay income tax on the converted amount now; the money then grows tax-free forever. Conversions make sense when your current tax rate is lower than your expected retirement rate. The backdoor Roth lets high earners contribute despite income limits. Conversions are now irreversible — you cannot recharacterize after the Tax Cuts and Jobs Act.
What Is a Roth Conversion?
A Roth conversion is the process of moving assets from a pre-tax retirement account — Traditional IRA, SEP-IRA, SIMPLE IRA, or a rolled-over 401(k) — into a Roth IRA. The key mechanic: the amount you convert is treated as ordinary income in the year of conversion. You pay tax now. In exchange, that money grows tax-free for the rest of its life in the Roth account, and qualified withdrawals in retirement are completely tax-free.
This is a fundamentally different deal from the Traditional IRA's tax-deferred model, where you defer taxes until withdrawal. With a Roth, you invert the tax timing — paying now at today's known rate instead of later at an unknown future rate.
The math of whether a conversion makes sense comes down to one question: will your tax rate in retirement be higher or lower than your current rate? If higher — convert now. If lower — it may not be worth it.
Traditional vs Roth: The Fundamental Trade-off
Pay Now vs. Pay Later: Same Tax Rate = Same Result
If your tax rate stays exactly the same from today to retirement, a Roth conversion is mathematically neutral. The advantage comes from the difference in rates.
Traditional IRA — Pay Later
- Contribution: $6,500 (pre-tax deductible)
- After 30 years at 8%: ~$65,400
- Withdraw at 22% tax rate: $50,900 net
- Required Minimum Distributions start at 73
- Heirs pay income tax on inherited amounts
Roth IRA — Pay Now
- Contribution: $6,500 (after-tax — you already paid 22%)
- After 30 years at 8%: ~$65,400
- Withdraw tax-free: full $65,400 net
- No Required Minimum Distributions ever
- Heirs inherit tax-free (10-year rule applies)
Note: Example assumes 22% tax rate both now and in retirement. Numbers simplified for illustration.
When a Roth Conversion Makes Financial Sense
You expect to be in a higher tax bracket in retirement
If you're early in your career and expect income to grow significantly, or if you have a large Traditional IRA that will generate substantial RMDs, your retirement tax rate could easily exceed your current rate. Converting now at a lower rate saves money over the long term.
You have a temporarily low-income year
Career break, sabbatical, startup year with low income, early retirement before Social Security kicks in — any year with unusually low taxable income is an opportunity to convert at a low rate. You can fill up your current tax bracket with converted income without jumping to a higher rate.
You have a long time horizon
The longer the converted money has to grow tax-free, the more valuable the Roth treatment becomes. A 35-year-old converting $50,000 gets 30+ years of tax-free compounding. A 62-year-old converting the same amount gets far less tax-free runway.
Tax rates are expected to rise
The Tax Cuts and Jobs Act's individual tax rate reductions are scheduled to expire after 2025 unless Congress extends them. Converting before rates revert to higher levels could lock in today's lower rates permanently.
Estate planning — tax-free inheritance
Roth IRAs are passed to heirs without the income tax burden of Traditional IRAs. If you have significant wealth and want to leave tax-efficient assets to beneficiaries, Roth conversions are one of the most powerful estate planning tools available.
When a Roth Conversion Does NOT Make Sense
You're near retirement with low expected income
If you're close to retirement and expect low taxable income (small RMDs, Social Security below threshold, minimal other income), your retirement tax rate may actually be lower than today's rate. Converting at a higher rate to save at a lower rate is a losing trade.
You can't pay the tax from outside the IRA
If you have to use the converted funds themselves to pay the tax bill, you lose a significant portion to taxes and early withdrawal penalties. Conversions make the most financial sense when you can pay the tax from taxable accounts or current income.
Conversion pushes you into a much higher bracket
Converting a large amount in one year can push income into a significantly higher bracket, making the tax cost excessive. It's usually better to do partial conversions over multiple years, filling up each bracket without jumping to the next.
You need the money within 5 years
Each Roth conversion has its own 5-year clock. Withdrawing converted amounts before 5 years (and before age 59½) triggers a 10% penalty on the principal. If you may need the funds soon, a conversion is risky.
The Backdoor Roth IRA: High-Income Strategy
In 2026, the ability to contribute directly to a Roth IRA phases out for single filers above $150,000 MAGI and joint filers above $236,000. The backdoor Roth IRA is a legal workaround for those above these limits.
Backdoor Roth: Step-by-Step
Make a non-deductible Traditional IRA contribution
Contribute up to $7,000 ($8,000 if 50+) to a Traditional IRA. There is no income limit for non-deductible contributions. File Form 8606 to record the after-tax basis.
Wait briefly for the contribution to clear
Most advisors recommend waiting a few days for the funds to settle before converting. Some brokers require this; others allow immediate conversion.
Convert the Traditional IRA to Roth
Convert the full balance to your Roth IRA. Since you contributed after-tax dollars and there was minimal or no investment gain, you owe little or no tax on the conversion.
Report on Form 8606
File Form 8606 with your tax return to document the non-deductible contribution basis and the conversion. This prevents you from being taxed again on the after-tax amounts.
The Pro-Rata Rule: The Biggest Backdoor Roth Trap
If you have any pre-tax money in any Traditional IRA, SEP-IRA, or SIMPLE IRA, the IRS applies the pro-rata rule when calculating the tax on your conversion. You cannot cherry-pick the after-tax money to convert — the IRS treats all your IRA funds as one pool.
Example:
You have $90,000 in a Traditional IRA (pre-tax) and add $10,000 as a non-deductible contribution. Total IRA: $100,000 — 90% pre-tax, 10% after-tax. If you convert $10,000, the IRS says only 10% of it ($1,000) is after-tax. You owe tax on the remaining $9,000 — not zero. The backdoor Roth only works cleanly if you have NO pre-existing pre-tax IRA funds.
IRA Accounts Trigger a Second Wash Sale Trap
Active Roth converters who also tax-loss harvest in taxable accounts face a hidden danger: if you sell a position at a loss in your brokerage account and buy the same (or substantially identical) security inside any IRA within the 30-day window — including the Roth you just funded — the IRS disallows the loss permanently. Unlike the usual wash sale where the loss is deferred to the replacement lot, an IRA replacement purchase destroys the loss forever. You never get it back.
The more IRA accounts you actively manage (Traditional + Roth + spousal IRAs), the wider the cross-account surface area becomes — especially in the weeks surrounding a conversion when you may be rebalancing across all of them simultaneously.
Wash Sale Rule: Full Breakdown + IRA TrapsThe Two 5-Year Rules You Need to Know
Roth IRAs have two separate 5-year rules, and confusing them is a common and expensive mistake:
5-Year Rule #1: Roth IRA Contributions
To withdraw Roth IRA earnings tax-free, you must have had a Roth IRA open for at least 5 years AND be 59½ or older. This 5-year clock starts on January 1 of the year you first made any Roth IRA contribution — and it only needs to be satisfied once, ever, for all your Roth accounts.
- Applies to: earnings withdrawals
- Clock starts: January 1 of first contribution year
- Only one 5-year clock per person (not per account)
- You can always withdraw contributions penalty-free
5-Year Rule #2: Roth Conversions
Each Roth conversion has its own 5-year clock. If you withdraw converted amounts before 5 years have passed AND before age 59½, you owe a 10% early withdrawal penalty on the converted principal — even though you already paid income tax on it when you converted.
- Applies to: converted principal (not earnings)
- Separate 5-year clock per conversion
- Only matters if under 59½
- After 59½, this rule is irrelevant
How to Actually Do a Roth Conversion: Step by Step
Decide how much to convert
Calculate how much you can convert without jumping into a higher tax bracket. Fill up the current bracket — stop at the next bracket threshold. Partial conversions over multiple years are often more tax-efficient than a single large conversion.
Open a Roth IRA if you don't have one
You need a Roth IRA account at your broker before you can convert. Most major brokers (Fidelity, Schwab, Vanguard, etc.) allow you to open a Roth IRA with no minimum deposit and convert the same day.
Initiate the conversion at your broker
Log into your brokerage account and find the "IRA conversion" or "Roth conversion" option. You'll choose which Traditional IRA funds to convert and the amount. Most brokers process this in 1–3 business days.
Pay the taxes from outside the IRA
Do NOT withhold taxes from the conversion itself. Have the full amount transferred to the Roth IRA, then pay the tax bill from your taxable account. Withholding reduces the converted amount and can trigger a 10% early withdrawal penalty on the withheld portion if under 59½.
File Form 8606 with your tax return
Report the conversion on Form 8606 as part of your annual tax return. This documents the conversion and the taxable amount. The 1099-R from your broker will also reflect the conversion.