How to Do a Backdoor Roth IRA in 2026
Quick Answer
A backdoor Roth is a four-step process: (1) Contribute $7,000 non-deductibly to a traditional IRA, (2) Immediately convert to Roth IRA, (3) File Form 8606 reporting the non-deductible contribution, (4) No tax is owed on the conversion (assuming no pre-tax IRA balances). Repeat annually. High earners above Roth phase-out limits ($146,000 single, $230,000 married) can use backdoor Roths to build unlimited tax-free wealth legally.
Why Backdoor Roths Exist
Roth IRAs have income phase-out limits ($146,000–$156,000 for single, $230,000–$240,000 for married). High earners can't contribute directly.
However, the IRS allows anyone to convert a traditional IRA to a Roth, regardless of income. The backdoor Roth exploits this by:
- Putting non-deductible money in a traditional IRA.
- Converting it to Roth (where the contribution was post-tax, so no tax owed).
- Building a Roth IRA with tax-free growth.
Repeated annually, backdoor Roths let high earners build unlimited Roth wealth.
Prerequisites: Clean Up Your IRAs
The "pro-rata rule" complicates backdoor Roths if you have pre-tax IRA balances. Solution: roll traditional IRAs into your 401(k) before the backdoor Roth.
Step 0: Verify your 401(k) plan accepts rollovers.
Call HR or check your plan document. Most 401(k)s accept incoming rollovers.
Step 1: Initiate IRA-to-401(k) rollover.
Contact your IRA custodian (Fidelity, Schwab, etc.) and request a rollover of your traditional IRA balance to your 401(k). This takes 1–2 weeks.
After rollover completion, your traditional IRA balance should be $0 (or nearly $0).
This step is crucial. If you skip it and have a $50,000 traditional IRA, the pro-rata rule will apply, making your backdoor Roth conversion taxable.
The Four Steps of Backdoor Roth
Step 1: Contribute $7,000 Non-Deductibly to Traditional IRA
Open a traditional IRA or use an existing one (after rolling out pre-tax balances in Step 0).
Contribute $7,000. Important: Do not deduct this contribution (you can't deduct it anyway if your income is over phase-out limits for deductibility).
Document that this is a non-deductible contribution. Some custodians have a checkbox for this; others require you to note it.
Timing: You can contribute anytime in the calendar year or up to the tax deadline (April 15 next year for the prior year's contribution).
Step 2: Immediately Convert to Roth
Within days of the contribution (ideally 2–7 days), instruct your custodian to convert the $7,000 from the traditional IRA to your Roth IRA.
The conversion should happen quickly. The IRS's position is that conversions should happen "immediately" after non-deductible contributions. Letting the money sit and earn returns before converting can attract IRS scrutiny (though in practice, waiting a few weeks is typically fine).
Most custodians can process conversions online or via phone in minutes.
Step 3: File Form 8606
When you file your tax return, include Form 8606 (Nondeductible IRAs). This form tells the IRS:
- You made a non-deductible contribution of $7,000.
- You converted $7,000 to a Roth.
- Taxable conversion amount: $0 (since the entire $7,000 was non-deductible).
Form 8606 example:
- Line 1: Non-deductible contribution = $7,000
- Line 2: Basis in traditional IRAs = $7,000
- Line 3: Amount converted = $7,000
- Line 4 (final): Taxable amount = $0
This form proves to the IRS that your conversion is tax-free.
Step 4: Repeat Annually
Each January (or before tax deadline), repeat the process:
- Contribute $7,000 non-deductibly to traditional IRA.
- Convert immediately to Roth.
- Report on Form 8606 for that tax year.
Over 40 years (ages 25–65), you've contributed $280,000. At 8% annual return, it grows to $1,200,000+, entirely tax-free.
The Pro-Rata Rule Trap
If you have any pre-tax IRA balance when you convert, the pro-rata rule applies:
Pro-ratio calculation: (Pre-tax IRA balance / Total IRA balance) × Converted amount = Taxable conversion
Example:
- You have a $50,000 traditional IRA with pre-tax money.
- You contribute $7,000 non-deductibly to a traditional IRA.
- Total IRA balances: $57,000.
- Pre-tax percentage: $50,000 / $57,000 = 87.7%.
- You convert the $7,000.
- Taxable conversion: 87.7% × $7,000 = $6,140 (you owe tax on $6,140).
This defeats the purpose. The solution is to roll the $50,000 into your 401(k) before contributing and converting.
Critical step: Before any backdoor Roth, ensure you have $0 (or near $0) in traditional, SEP, and SIMPLE IRAs. Rolling them into a 401(k) is the fix.
Mega Backdoor Roth
Some 401(k) plans allow in-plan Roth conversions or after-tax (non-Roth) contributions, creating a "mega backdoor Roth."
How it works:
- Contribute up to $46,000 (2026 limit for total employee + employer contributions is $69,000; subtract $23,500 employee deferral = $45,500 remaining).
- This after-tax amount is contributed to the 401(k).
- Immediately convert to Roth 401(k) or roll to Roth IRA.
- Tax-free conversion (like regular backdoor Roth).
Result: You've contributed $23,500 traditional + $45,500 mega backdoor = $69,000 total retirement savings, with $45,500 in tax-free Roth.
Ask your plan administrator if they allow after-tax contributions and in-plan Roth conversions.
Spousal Backdoor Roths
Married couples can each do a backdoor Roth:
- Spouse 1: $7,000 non-deductibly to traditional IRA, convert to Roth.
- Spouse 2: $7,000 non-deductibly to their own traditional IRA, convert to their Roth IRA.
- Total: $14,000 backdoor Roths annually.
Important: Each spouse must have their own separate IRA. Don't put both spouses' money in one IRA; it complicates pro-rata calculations.
Each spouse files their own Form 8606.
Timing: Best Time to Contribute
Contribute early in the year (January–February) to:
- Minimize the time between contribution and conversion (reduce pro-rata rule risk).
- Let the converted funds grow tax-free for the full year.
- Give yourself time to catch errors before tax filing (April 15 next year).
Or, wait until you've calculated your final income (September–October) to ensure you're eligible (over Roth phase-out limits, confirming you need backdoor Roth).
Most people contribute early (January) and don't overthink it.
Watch Out for Employer Plans
If you're a business owner with employees, backdoor Roths are more complex. Employees might demand matching contributions if you're contributing to a 401(k). This can complicate or prevent the strategy.
Sole proprietors and business owners without employees have no issue.
Common Mistakes
Not rolling out pre-tax IRAs: Leaving a traditional IRA with pre-tax money triggers pro-rata taxation, making the conversion partly taxable.
Delaying the conversion: Contributing in January but converting in June. The longer you wait, the more gains accrue in the traditional IRA, which are taxable upon conversion.
Forgetting Form 8606: Failing to file Form 8606 creates tax reporting issues. The IRS won't know the conversion is tax-free.
Mixing spousal accounts: If married, each spouse needs their own traditional IRA for clarity. Shared accounts complicate pro-rata calculations.
Contributing more than allowed: Contributing $8,000 when the limit is $7,000. This triggers a 6% penalty on excess contributions.
Tax Reporting
Form 8606 is filed with your Form 1040. The form reconciles:
- Non-deductible contributions made.
- Conversion amounts.
- Taxable conversion (if any).
The custodian also files Form 5498 (IRA contribution reporting) and Form 1099-R (distribution/conversion reporting). The IRS matches these forms to your return to verify accuracy.
Withdrawal Rules for Backdoor Roths
After conversion, your backdoor Roth follows standard Roth IRA rules:
- Five-year rule: You must hold the account 5 tax years before withdrawing earnings tax-free (contributions can be withdrawn anytime).
- Age 59.5: Withdrawals of both contributions and earnings are tax-free if age 59.5+ and held 5 years.
- Before 59.5: Withdrawals of contributions (what you put in) are tax-free and penalty-free. Withdrawals of earnings are taxed + 10% penalty.
Since you're converting non-deductible contributions (no earnings to speak of), you can withdraw the $7,000 contribution anytime without tax or penalty.
Recurring Backdoor Roths: Automation
After the first year, repeat the same process annually:
- January: Contribute $7,000 non-deductibly to traditional IRA.
- Within 1 week: Convert to Roth.
- Tax filing: Report on Form 8606.
Many advisors recommend automating this—setting up a calendar reminder each January.
Sources
- Internal Revenue Service. "Roth Conversions." IRS.gov.
- Internal Revenue Service. Form 8606: Nondeductible IRAs.
- Internal Revenue Service. "Pro-Rata Rule." IRS.gov.
- IRS Publication 590-A: Contributions to Individual Retirement Arrangements (IRAs).
- IRS Publication 590-B: Distributions from Individual Retirement Arrangements (IRAs).
- CFA Institute. "Backdoor Roth Strategies for High-Earner Planning."