A backdoor Roth IRA is a two-step strategy that lets high earners contribute to a Roth IRA even when their income exceeds the direct contribution limit. There is nothing illegal or even unusual about it — the IRS has acknowledged it as a legitimate strategy. In 2026, the ability to contribute directly to a Roth IRA phases out between $150,000–$165,000 for single filers and $236,000–$246,000 for married filing jointly. If you earn above those thresholds, the backdoor is your path in.
The Two-Step Process
The backdoor Roth works because there is no income limit on converting a traditional IRA to a Roth IRA, even though there is an income limit on contributing directly to a Roth IRA.
- Make a non-deductible contribution to a traditional IRA. In 2026, the limit is $7,000 ($8,000 if you are 50 or older). Anyone with earned income can do this regardless of income level. Because you already paid tax on this money and the contribution is non-deductible, it has a “basis” of $7,000 — meaning it is after-tax money.
- Convert the traditional IRA to a Roth IRA. Shortly after making the contribution (typically within a few days to a week), request a Roth conversion for the full balance. The conversion moves the money from the traditional IRA to the Roth IRA. Because the original contribution was non-deductible, the conversion triggers little to no tax — you’ve already paid tax on the principal, and if there is no growth between contribution and conversion, the taxable amount is $0.
The Pro-Rata Rule: The Most Important Caveat
The backdoor Roth strategy works cleanly only if you have no other pre-tax traditional IRA funds. If you do, the IRS applies the pro-rata rule, which treats all your IRA money as a single pool when calculating how much of a conversion is taxable.
Example: You have $63,000 in a pre-tax IRA from a previous 401(k) rollover, plus the new $7,000 non-deductible contribution — a total of $70,000. When you convert $7,000, the IRS treats 10% of it ($700) as after-tax and 90% ($6,300) as pre-tax. You owe income taxes on that $6,300. The backdoor becomes much less attractive or outright unfavorable in this situation.
Solutions to the pro-rata problem:
- Roll your pre-tax IRA funds into your current employer’s 401(k) before doing the backdoor Roth. 401(k) balances are not included in the pro-rata calculation for IRA conversions.
- If your employer’s plan accepts rollovers, this clears the path for a clean backdoor conversion.
Reporting the Backdoor Roth on Your Tax Return
The backdoor Roth requires Form 8606 to be filed with your tax return every year you make a non-deductible IRA contribution. Form 8606 tracks your IRA basis (the after-tax money you’ve contributed) so the IRS knows which portion of any future conversions or withdrawals is taxable. If you skip this form, you risk being taxed twice on the same money when you withdraw.
Your IRA custodian will also send you Form 1099-R showing the conversion. The taxable amount should be $0 (or close to it) if you completed the conversion promptly with no earnings on the non-deductible contribution.
Mega Backdoor Roth: A More Powerful Variation
If your 401(k) plan allows after-tax contributions and in-service withdrawals or conversions, you can execute a mega backdoor Roth. This lets you contribute an additional $46,500 (the gap between the $70,000 total 401(k) contribution limit and the $23,500 employee limit in 2026) as after-tax 401(k) contributions, then convert them to a Roth IRA or Roth 401(k). Not all employers allow this — you need to check your plan documents.
Is the Backdoor Roth Worth It?
Yes, for most high earners with no pre-existing traditional IRA balances. Roth IRA money grows tax-free, withdrawals in retirement are tax-free, and Roth IRAs have no required minimum distributions during the owner’s lifetime. The $7,000 annual contribution is modest, but compounding over 20–30 years in a tax-free account is meaningful.
If you have a large pre-tax IRA balance and cannot roll it into a 401(k), the pro-rata rule may make the backdoor impractical. Talk to a tax professional about your specific situation before proceeding.
Bottom Line
The backdoor Roth IRA is a straightforward two-step process: make a non-deductible traditional IRA contribution, then convert it to Roth. The main complication is the pro-rata rule, which can create an unexpected tax bill if you have pre-tax IRA balances. File Form 8606 every year. Do it early in the year while the contribution has no time to generate earnings that would trigger tax on conversion.