Retirement & Tax Strategy
Roth Conversion Guide
When to convert, how much to convert, and the strategies the wealthy use to build tax-free retirement income — explained by someone who does them every year.
Updated April 2026 · ~14 min read
What Is a Roth Conversion?
A Roth conversion moves money from a tax-deferred account (traditional IRA, traditional 401(k), SEP IRA, SIMPLE IRA) into a Roth IRA. You pay income tax on the converted amount this year, and in return the money grows tax-free and withdrawals in retirement are completely tax-free.
Think of it as paying your tax bill early at a known rate instead of gambling on what rates will be in 20 or 30 years. If you convert $50,000 at a 22% federal rate, you owe $11,000 in taxes now, but that $50,000 (and everything it grows into) is never taxed again.
There is no income limit on Roth conversions. Anyone can convert regardless of how much they earn. There is also no limit on how much you can convert in a single year. The only constraint is how much tax you are willing to pay.
When to Convert: 7 Scenarios Analyzed
The decision to convert depends entirely on your current tax bracket versus your expected future tax bracket. Here are the most common scenarios:
Lower income year (sabbatical, layoff, early retirement)
Your taxable income is temporarily low, pushing you into the 12% or 22% bracket instead of your usual 32%+.
This is the golden window. Converting at 12% when you normally pay 32% means you save 20 cents on every dollar converted. Fill up the lower brackets with conversions.
Early retiree before Social Security and RMDs kick in
You are retired but haven't started Social Security (age 62-70) and don't have RMDs yet (age 73+).
These are the 'gap years' with low taxable income. Convert enough each year to fill the 12% or 22% bracket. Once Social Security and RMDs start, your taxable income rises and conversions become more expensive.
You expect to be in a higher tax bracket in retirement
Large traditional IRA/401(k) balances, pension income, or you believe tax rates will increase overall.
If future rates are higher, paying taxes now at today's rate is a better deal. A $1M traditional IRA at age 73 generates $37,700+ in RMDs — that's potentially $37K+ in forced taxable income you can't control.
You want to leave a tax-free inheritance
Your beneficiaries (non-spouse) must empty an inherited IRA within 10 years under the SECURE Act, often at their peak earning years.
Inheriting a traditional IRA means your kids pay taxes on distributions at their rate (potentially 32-37%). Inheriting a Roth IRA means 10 years of tax-free withdrawals. You pay the tax now so they don't have to.
You are in your peak earning years (35-55, high bracket)
Household income over $400K, taxed at 32-37% federal plus state taxes.
Converting at 35%+ makes the math very hard to justify unless you are certain rates will be even higher in retirement. Focus on backdoor Roth and mega backdoor Roth instead — those involve new contributions, not conversions of existing pre-tax money.
You need the money within 5 years
You might need to access the converted funds before 5 years have passed.
Converted amounts have their own 5-year clock. Withdrawing converted amounts within 5 years triggers a 10% penalty if you're under 59.5. If you're over 59.5, the 5-year rule doesn't apply to converted amounts (only earnings).
Your state has no income tax
You live in a state like Florida, Texas, Nevada, or Washington with no state income tax.
You avoid state taxes on the conversion entirely. If you might move to a state with income tax later, converting now in a no-tax state is even more valuable.
Glen's Take
I do a backdoor Roth every single year. The 15 minutes it takes to contribute to a non-deductible traditional IRA and convert to Roth is the highest ROI activity in my financial life. It is free money — well, free tax-free growth.
The biggest mistake I see is people waiting for the "perfect" time to convert. There is no perfect time. If you are in a low bracket, convert. If you are in a high bracket, do the backdoor Roth for new money and wait for a low bracket year to do larger conversions. The worst strategy is doing nothing and letting your traditional IRA grow into a tax bomb that explodes when RMDs start at age 73.
The Roth Conversion Ladder (Early Retirees)
The Roth conversion ladder is the cornerstone strategy for early retirees who need to access retirement money before age 59.5 without paying the 10% early withdrawal penalty.
Here is how it works:
Convert $50K from traditional IRA to Roth. Pay taxes on the $50K. Start the 5-year clock.
Convert another $50K. Live off taxable savings, side income, or Roth contributions (always penalty-free).
Keep converting $50K each year. Still living off taxable savings and Roth contributions.
The Year 1 conversion is now past its 5-year clock. Withdraw it penalty-free. Each subsequent year, another $50K becomes available.
The ladder requires 5 years of living expenses outside the traditional IRA. This is why financial independence advocates emphasize building a taxable "bridge" account before early retirement.
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Backdoor Roth IRA: Step by Step
The backdoor Roth is a two-step process that lets high earners (above the Roth IRA income limits) still get money into a Roth IRA every year. It is completely legal and IRS-sanctioned.
Contribute to a traditional IRA (non-deductible)
Contribute $7,000 (2026 limit; $8,000 if 50+). Do NOT deduct it on your tax return. File Form 8606 to report the non-deductible contribution.
Convert the traditional IRA to a Roth IRA
Call your broker (or click a button online) to convert the traditional IRA to Roth. Since you already paid taxes on the contribution, the conversion should be tax-free.
Avoid the pro-rata trap
If you have ANY pre-tax money in ANY traditional IRA (including SEP and SIMPLE IRAs), the pro-rata rule applies and part of the conversion is taxable. Solution: roll all pre-tax IRA money into your 401(k) before doing the backdoor Roth.
Mega Backdoor Roth: The $46K Strategy
The mega backdoor Roth is the most powerful Roth funding strategy available. It lets you contribute up to $46,000+ per year into a Roth — far beyond the normal $7,000 limit.
Here is how it works:
- Total 401(k) limit (2025): $70,000 (includes all sources: employee, employer, after-tax)
- Employee pre-tax/Roth: $23,500
- Employer match: Varies (e.g., $5,000)
- Remaining room for after-tax: $70,000 - $23,500 - $5,000 = $41,500
You make after-tax contributions to your 401(k), then immediately convert them to Roth (either in-plan Roth conversion or roll out to a Roth IRA). Since the contributions were after-tax, the conversion is (mostly) tax-free.
Requirements: Your employer's 401(k) must allow (1) after-tax contributions AND (2) in-service withdrawals or in-plan Roth conversions. Not all plans offer this — check with HR.
The 3 Roth 5-Year Rules (Yes, There Are Three)
The "5-year rule" is actually three separate rules that apply to different situations. Confusing them can cost you money.
5-Year Rule #1: Roth Contributions
Contributions (not conversions, not earnings) can always be withdrawn tax-free and penalty-free at any time. No 5-year rule applies to direct Roth contributions. This is one of the best features of the Roth.
5-Year Rule #2: Roth Conversions
Each conversion has its own 5-year clock. If you withdraw converted amounts within 5 years AND you're under age 59.5, you pay a 10% early withdrawal penalty (but no income tax, since you already paid tax on the conversion). After age 59.5, there is no penalty on converted amounts regardless of the 5-year rule.
5-Year Rule #3: Roth Earnings
Earnings are tax-free and penalty-free only if: (a) the Roth has been open for at least 5 years, AND (b) you are 59.5 or older (or disabled, or using $10K for first home). Both conditions must be met. The 5-year clock starts January 1 of the year of your first Roth contribution or conversion ever.
Roth Conversion Tax Math: A Real Example
Let's say you are a single filer with $80,000 in taxable income. You want to convert $25,000 from your traditional IRA to Roth.
2025 Tax Bracket Analysis
- Current taxable income: $80,000 (22% bracket, up to $103,350)
- Room left in 22% bracket: $103,350 - $80,000 = $23,350
- Converting $25,000 means: $23,350 taxed at 22% + $1,650 taxed at 24%
- Tax on conversion: ($23,350 x 0.22) + ($1,650 x 0.24) = $5,137 + $396 = $5,533
- Effective rate on conversion: 22.1%
If that $25,000 grows at 8% for 25 years, it becomes $171,212 — and you will never pay a cent of tax on it. The $5,533 you paid today saved you $37,667+ in future taxes (at a 22% rate).
The key insight: you want to convert enough to fill your current bracket but not so much that you push yourself into a significantly higher bracket. Use our Roth Conversion Calculator to model the exact numbers for your situation.
5 Common Roth Conversion Mistakes
Paying the conversion tax from IRA funds
Fix: Pay taxes from a separate taxable account. Using IRA funds to pay taxes reduces the amount converting to Roth AND may trigger a 10% penalty if you're under 59.5.
Forgetting about Medicare IRMAA surcharges
Fix: A large conversion can bump your Modified AGI above IRMAA thresholds, increasing Medicare Part B and D premiums for 2 years. Plan conversions to stay below $103,000 (single) / $206,000 (married) to avoid surcharges.
Ignoring the pro-rata rule
Fix: If you have pre-tax IRA money and try a backdoor Roth, a portion of the conversion will be taxable. Roll pre-tax money into your 401(k) first.
Converting too much in one year
Fix: Converting $500K in a single year pushes you into the 37% bracket. Spreading it over 5-10 years at lower rates saves significantly more. This is where the conversion ladder shines.
Not considering state taxes
Fix: States like California tax conversions at up to 13.3%. If you plan to relocate to a no-income-tax state, consider waiting to convert until after you move.
Recommended Resources
Tools & books I actually use and recommend
Interactive Brokers
Low commissions, global market access, and professional-grade tools. This is where I hold my positions.
Open an AccountThe Psychology of Money
Morgan Housel on why managing money is about behavior, not intelligence. Short, brilliant chapters you'll re-read.
View on AmazonA Random Walk Down Wall Street
Burton Malkiel's classic case for index investing. The book that convinced millions to stop stock-picking.
View on AmazonSome links above are affiliate links. I only recommend products I personally use. See my full disclosures.
Frequently Asked Questions
What is a Roth conversion?
A Roth conversion moves money from a traditional IRA or traditional 401(k) into a Roth IRA. You pay income tax on the converted amount in the year of conversion. After that, the money grows tax-free and withdrawals in retirement are tax-free. There is no income limit on conversions — anyone can convert regardless of how much they earn.
How much should I convert to a Roth each year?
The optimal conversion amount fills your current tax bracket without pushing you into the next one. For example, if you're single and your taxable income is $80,000, you're in the 22% bracket (up to $103,350 in 2025). You could convert up to $23,350 at 22%. Converting more would be taxed at 24%. Many advisors recommend filling the 22% or 24% bracket as a sweet spot.
What is a backdoor Roth IRA?
A backdoor Roth is a legal workaround for high earners who exceed Roth IRA income limits ($161,000 single / $240,000 married in 2026). You contribute to a non-deductible traditional IRA, then immediately convert it to a Roth IRA. Since you already paid taxes on the contribution (it was non-deductible), the conversion is tax-free — assuming you have no other pre-tax IRA balances (pro-rata rule).
What is a mega backdoor Roth?
The mega backdoor Roth lets you contribute up to $46,000 extra per year (2025 limit; $70,000 total 401(k) limit minus $23,500 employee contribution minus employer match) via after-tax 401(k) contributions, then convert those to a Roth IRA or Roth 401(k). This requires your employer's 401(k) plan to allow after-tax contributions AND in-service distributions or in-plan Roth conversions. Not all plans offer this, but if yours does, it is the most powerful Roth funding strategy available.
What is the pro-rata rule and how does it affect backdoor Roth?
The pro-rata rule says the IRS treats all your traditional IRA money as one pool — you cannot cherry-pick which dollars to convert. If you have $95,000 pre-tax and $5,000 after-tax in your traditional IRAs, converting $5,000 does not mean you only convert the after-tax money. Instead, 95% of the conversion ($4,750) is taxable. Solution: roll all pre-tax IRA money into your employer's 401(k) before doing a backdoor Roth. This leaves only after-tax dollars in the IRA.
Can I undo a Roth conversion?
No. Since 2018, recharacterization of Roth conversions has been permanently eliminated by the Tax Cuts and Jobs Act. Once you convert, it is done — you owe tax on the converted amount for that year. This makes it important to calculate the tax impact before converting rather than trying to undo it later.
Does a Roth conversion count as income for Social Security?
A Roth conversion increases your Adjusted Gross Income (AGI) for the year, which can cause up to 85% of your Social Security benefits to be taxable. It does NOT count as earned income for Social Security tax purposes (no FICA). This is another reason early retirees should do conversions in the gap years before Social Security starts.
The Bottom Line
A Roth conversion is one of the most powerful tools in the tax code — if you time it right. The ideal conversion happens in low-income years when your marginal rate is lower than what you expect to pay in retirement. Backdoor and mega backdoor strategies let high earners fund Roth accounts regardless of income limits.
The worst outcome is doing nothing and letting a large traditional IRA grow into a tax time bomb that detonates at age 73 when RMDs force you to take distributions at whatever rate Congress decides.
Disclaimer: This is educational content, not tax advice. Consult a qualified CPA or tax professional for advice specific to your situation. Glen Bradford is not a CPA, enrolled agent, or tax attorney.
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