What a backdoor Roth conversion is

A backdoor Roth conversion is a way to move money into a Roth IRA when your income is too high to contribute directly. You put after-tax money into a traditional IRA, then convert that money to a Roth IRA. The IRS allows this move, and it lets higher earners build a Roth balance that would otherwise be closed to them.

The mechanics are straightforward: you fund a traditional IRA with money you've already paid income tax on, then when ready request a conversion to your Roth IRA. The converted amount moves over, and from that point forward, the money grows tax-free and you can withdraw it tax-free in retirement (as long as you follow the rules).

This is not a loophole or a trick. The IRS acknowledges this strategy in its own guidance. Thousands of people use it every year, and it's a standard move for financial advisors to discuss with high-income clients.

Key Takeaways

  • A backdoor Roth works by funding a traditional IRA with after-tax money, then converting it to a Roth IRA in the same year.
  • You can do a backdoor Roth regardless of your income level, which is why it matters for people who earn too much to contribute to a Roth directly.
  • The conversion itself is not a taxable event if you're converting after-tax money, but you must track basis (the amount you've already paid tax on) carefully.
  • If you have other traditional IRAs with pre-tax money in them, the pro-rata rule may force you to pay tax on part of the conversion.
  • You report the conversion on Form 8606 when you file your tax return, and your brokerage will send you a 1099-R.

Why income limits make a backdoor Roth necessary

The IRS sets income limits on who can contribute directly to a Roth IRA. For 2024, if you're single and earn more than a certain amount, you cannot put new money into a Roth through the normal contribution route. The limit is higher if you're married filing jointly, but it still phases out at higher incomes.

A backdoor Roth bypasses this limit entirely. You're not technically contributing to the Roth—you're converting money that's already in a traditional IRA. The IRS does not restrict conversions based on income, so this path stays open no matter how much you earn.

This is why the strategy exists: it's the only way for high earners to build new Roth balances year after year.

The pro-rata rule and why it matters

The pro-rata rule is the biggest complication in a backdoor Roth. If you have any traditional IRAs, SEP IRAs, or straightforward IRAs with pre-tax money in them, the IRS treats all your IRAs as one pool when you convert. You cannot cherry-pick just the after-tax money to convert.

Here's how it works: if you have $50,000 in a traditional IRA (pre-tax) and you add $7,000 in after-tax money, then convert the $7,000, the IRS says you're converting 12.3% pre-tax money and 87.7% after-tax money. You pay income tax on the pre-tax portion of the conversion. This can wipe out the tax benefit of the backdoor Roth entirely.

The solution is to move any pre-tax IRA money to a workplace plan like a 401(k) or 403(b) if your plan allows it. Once that pre-tax money is out of the IRA system, the pro-rata rule no longer applies to your conversion. This is why many people check their IRA balances before attempting a backdoor Roth.

How to execute a backdoor Roth step by step

The process takes two main steps, though the timing matters.

First, fund a traditional IRA with after-tax money. You can do this at any brokerage that offers IRAs—Fidelity, Vanguard, Charles Schwab, and others all support this. Write a check, transfer from your bank account, or move money from another account. The IRS does not require you to wait any specific time before converting.

Second, request a conversion from your traditional IRA to your Roth IRA. Most brokerages let you do this online or by calling. You specify the amount (usually the full $7,000 or whatever you just deposited) and which Roth IRA to convert it to. The brokerage handles the paperwork and the money moves within days.

Do both steps in the same calendar year. The IRS treats backdoor Roths by the year you make the conversion, not by when you funded the traditional IRA. Many people do the funding in late December and the conversion in early January of the following year, but as long as both happen within one calendar year, you're fine.

Tax reporting and what forms you'll receive

Your brokerage will send you a Form 1099-R for the conversion. This form reports the amount converted and goes to the IRS. You also file Form 8606 with your tax return to report the non-taxable portion of the conversion (the after-tax money you contributed).

Form 8606 is where you tell the IRS that you've already paid tax on the money you converted, so it should not be taxed again. Without this form, the IRS may assume the entire conversion is taxable income. If you're working with a tax preparer or accountant, give them the 1099-R and let them know you did a backdoor Roth—they'll handle the 8606.

If you have a spouse and you both do backdoor Roths, each of you files your own Form 8606. The pro-rata rule applies to each person separately, so if your spouse has no traditional IRAs, their conversion is not affected by yours.

What happens if you have existing traditional IRA money

If you already have a traditional IRA balance—whether from a rollover, an old employer plan, or previous contributions—you have three options before doing a backdoor Roth.

The first option is to move the pre-tax money to a workplace retirement plan. If your employer offers a 401(k), 403(b), or similar plan, and the plan allows incoming rollovers, you can roll the traditional IRA balance into that plan. Once the money is out of the IRA system, the pro-rata rule no longer applies. This is the cleanest solution if your plan allows it.

The second option is to accept the pro-rata tax hit. If you have $100,000 in a traditional IRA and you convert $7,000, you'll owe income tax on roughly 7% of the conversion (the pre-tax portion). This might still be worth it if you expect the Roth to grow significantly over time, but it reduces the benefit.

The third option is to not do a backdoor Roth that year. You can wait until you've moved the pre-tax money out, or you can skip the strategy altogether. There's no penalty for not converting.

Common mistakes to avoid

The most common mistake is forgetting to file Form 8606. If you don't report the non-taxable portion of your conversion, the IRS may tax the entire amount. This creates a double-tax problem: you paid tax when you contributed the after-tax money, and now you're paying tax again on the conversion. Filing the form prevents this.

Another mistake is not checking for existing traditional IRA balances before converting. People sometimes forget about an old rollover IRA or a SEP IRA from self-employment income. The pro-rata rule catches them by surprise, and they end up with a larger tax bill than expected. A quick check of all your IRA accounts takes five minutes and can save you hundreds in taxes.

A third mistake is converting too quickly after funding. While there's no legal waiting period, converting within a few days can sometimes trigger IRS scrutiny if the money hasn't settled. Most advisors recommend waiting at least a few days, though this is more of a caution than a requirement.

Frequently Asked Questions

Can I do a backdoor Roth if I'm married?

Yes. Each spouse can do their own backdoor Roth in the same year. The pro-rata rule applies to each person separately, so if one spouse has traditional IRAs and the other doesn't, only the spouse with the IRAs faces the pro-rata issue. You each file your own Form 8606.

What if I make a mistake and convert too much money?

You can undo a conversion by requesting a recharacterization from your brokerage, though the rules around this changed in recent years. You have until your tax filing important date (including extensions) to undo a conversion. Contact your brokerage to request this—they'll move the money back to the traditional IRA and issue a corrected 1099-R.

Do I have to convert the entire amount I fund, or can I convert part of it?

You can convert any amount you want. Many people fund $7,000 (the annual contribution limit) and convert the full amount, but you could fund $10,000 and convert only $7,000 if you prefer. The pro-rata rule still applies to whatever you convert, so the amount you leave behind doesn't change the tax calculation.

What if my employer plan doesn't allow rollovers?

If you cannot move your traditional IRA money to your workplace plan, you'll face the pro-rata rule on any backdoor Roth conversion. You can still do the conversion, but you'll owe tax on the pre-tax portion. Some people accept this trade-off; others decide the tax hit is too large and skip the backdoor Roth that year.

Can I do a backdoor Roth every year?

Yes. As long as you have earned income and you follow the rules each year, you can do a backdoor Roth annually. Many high earners do this as part of their regular tax and retirement planning. Just remember to file Form 8606 each year you convert.