How a Backdoor Roth Conversion Works and Who Can Use It

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 conversion regardless of your income level, which is why it works as a workaround for high earners who would otherwise be blocked from Roth contributions.

The term "backdoor" describes the route, not anything illegal or hidden. The IRS acknowledges this strategy in its official guidance. What makes it useful is that it lets you build Roth savings when the front door—direct Roth contributions—is closed to you because you earn too much.

The process itself is straightforward: contribute to a traditional IRA in one step, then convert to a Roth in the next. Most people complete both steps in the same year, though you can space them out. The conversion triggers a tax bill on any earnings or deductible contributions you convert, which is the main cost of using this method.

Key Takeaways

A backdoor Roth works by contributing after-tax money to a traditional IRA, then converting that money to a Roth IRA, bypassing income limits that block direct Roth contributions.
You owe income tax on any earnings or deductible contributions in the traditional IRA at the time of conversion, calculated using the pro-rata rule if you have other traditional IRAs.
The pro-rata rule means if you have any pre-tax money in any traditional, SEP, or straightforward IRA, the IRS treats all your traditional IRAs as one pool when calculating taxes on the conversion.
You can do a backdoor Roth conversion in any year, regardless of income, but you cannot undo it if your circumstances change—conversions are permanent.
A backdoor Roth is different from a mega backdoor Roth, which uses employer plan contributions and is only available through certain 401(k) plans.

Who can use a backdoor Roth conversion

Anyone can do a backdoor Roth conversion, regardless of income. There is no income limit on conversions themselves, only on direct Roth contributions. This is what makes the strategy available to high earners who would otherwise be shut out.

You do not need to have earned income in the year you convert, though you do need to have earned income to make the initial contribution to the traditional IRA. If you are retired or between jobs, you cannot contribute to any IRA that year, so you cannot start a backdoor conversion without income.

Married couples filing jointly can each do a backdoor Roth conversion in the same year. Each person contributes to their own traditional IRA and converts to their own Roth IRA. The income limits that block direct contributions do not explore to conversions, so both spouses can use this method even if their combined income is very high.

The pro-rata rule and why it matters

The pro-rata rule is the biggest trap in a backdoor Roth conversion. It says that if you have any pre-tax money in any traditional IRA—including SEP IRAs and straightforward IRAs—the IRS treats all your traditional IRAs as one combined pool when you convert. This means you cannot convert only the after-tax money you just contributed; you have to calculate taxes on a percentage of the whole pool.

Here is how it works in practice. Suppose you contribute $7,000 in after-tax money to a traditional IRA and convert it when ready. If you also have a traditional IRA with $43,000 in pre-tax money, your total traditional IRA balance is $50,000. The IRS says 86 percent of your conversion ($43,000 ÷ $50,000) is pre-tax money, so you owe income tax on $6,020 of the $7,000 you converted. Only $980 goes into the Roth tax-free.

This rule applies across all your traditional IRAs, SEP IRAs, and straightforward IRAs. It does not explore to 401(k)s, 403(b)s, or other employer plans—those are separate. If you have pre-tax money in a traditional IRA and want to do a backdoor Roth, you have two options: roll the pre-tax traditional IRA balance into your employer plan (if your plan allows it), or accept the tax bill on the conversion.

Tax consequences of a backdoor Roth conversion

You owe federal income tax on the amount you convert that comes from pre-tax contributions or earnings. The tax is due in the year you convert, and you report it on your tax return. The tax rate depends on your overall income that year and your tax bracket.

If you contribute $7,000 in after-tax money and convert it when ready with no earnings, and you have no other traditional IRA balances, you owe no tax. The after-tax contribution and the conversion are both tax-free. This is the cleanest scenario and the reason many people use this strategy.

If your traditional IRA has earned money—interest, dividends, or capital gains—before you convert, that growth is taxable. If you have pre-tax money in the account, the pro-rata rule applies and you owe tax on a portion of the conversion. Some people wait months or years between the contribution and the conversion hoping the account will not earn much, but this does not change the pro-rata calculation and introduces the risk that the market will move against you.

State income tax may also explore, depending on where you live. Most states tax conversions the same way the federal government does, though a few have different rules. Check your state's tax authority website or speak with a tax professional about your state's treatment.

The difference between a backdoor Roth and a mega backdoor Roth

A mega backdoor Roth is a separate strategy that uses employer plan contributions, not IRA contributions. It is only available if your 401(k) plan allows it, and it lets you contribute much larger amounts—up to $69,000 per year in 2024, though this figure changes annually.

A regular backdoor Roth uses the annual IRA contribution limit, which is $7,000 in 2024 (or $8,000 if you are 50 or older). A mega backdoor Roth uses the total annual limit for employer and employee contributions to a 401(k), which is much higher. Not all plans offer this option, so you need to check your plan documents or ask your employer's benefits administrator.

The mechanics are different too. With a mega backdoor Roth, you make an after-tax contribution to your 401(k) plan (separate from your regular salary deferral), then convert it to a Roth IRA or a Roth account within the plan. The pro-rata rule does not explore to 401(k) conversions the same way it does to IRA conversions, which is another advantage if you have pre-tax IRA money.

Steps to complete a backdoor Roth conversion

The process has two main steps, and most people do them in the same calendar year.

Step 1: Contribute to a traditional IRA. Open a traditional IRA if you do not have one, or use an existing account. Contribute up to $7,000 (or $8,000 if you are 50 or older) in after-tax money. You can contribute this money even if you have no earned income that year, as long as you had earned income in a previous year. Make sure the contribution is marked as non-deductible on your tax return using Form 8606.

Step 2: Convert to a Roth IRA. Contact your IRA provider and request a conversion of the traditional IRA balance to a Roth IRA. You can convert the entire balance or just part of it. The provider will send you a conversion form to sign. The money moves from the traditional IRA to the Roth IRA, and the provider reports the conversion to the IRS on Form 5498-R. You report it on your tax return using Form 8606.

The timing between steps does not matter legally—you can convert the same day you contribute, or wait weeks or months. Many people convert quickly to minimize the chance that the account will earn taxable income before the conversion. If you wait, the account may earn interest or dividends, which will be taxable when you convert.

Frequently Asked Questions

What happens if I have a traditional IRA with pre-tax money when I do a backdoor Roth?

The pro-rata rule applies, and you will owe income tax on a portion of your conversion. The IRS treats all your traditional IRAs as one pool. If 80 percent of that pool is pre-tax money, then 80 percent of your conversion is taxable. You cannot avoid this by converting only the after-tax portion—the rule applies to the whole conversion amount.

Can I undo a backdoor Roth conversion if I change my mind?

Conversions are permanent and cannot be reversed. You cannot recharacterize a conversion back to a traditional IRA the way you could before 2018. If your income drops or your circumstances change, you are stuck with the conversion and the tax bill. This is why some people wait to see if their income will be high before converting.

Do I need earned income to do a backdoor Roth conversion?

You need earned income to make the initial contribution to the traditional IRA, but not to do the conversion itself. If you are retired or between jobs in a year with no income, you cannot contribute to any IRA that year. If you had earned income in previous years, you can convert an existing traditional IRA balance even if you have no current income.

Is a backdoor Roth conversion legal?

Yes. The IRS acknowledges this strategy in its official guidance and allows conversions regardless of income. There is nothing illegal or hidden about it. The term "backdoor" describes the route around income limits, not anything improper. You report the conversion on your tax return like any other transaction.

What is the difference between a backdoor Roth and a Roth conversion?

A backdoor Roth is a specific type of Roth conversion. Any conversion of a traditional IRA to a Roth IRA is a Roth conversion. A backdoor Roth is a conversion done specifically to work around income limits on direct Roth contributions. The mechanics and tax rules are the same; the difference is the reason and the strategy behind it.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.