A backdoor Roth is a way to move money into a Roth IRA when your income is too high for direct contributions

If your income exceeds the limits for putting money directly into a Roth IRA, a backdoor Roth conversion lets you accomplish the same thing through a two-step process. You contribute to a traditional IRA (which has no income limit), then convert that money to a Roth IRA. The IRS allows this conversion regardless of how much you earn.

The strategy works because the IRS does not restrict who can convert a traditional IRA to a Roth. It only restricts who can contribute directly to a Roth based on income. By using a traditional IRA as an intermediary, you sidestep the income cap.

This is a legal tax strategy, not a loophole. The IRS acknowledges it in its own guidance. However, it requires careful execution because a mistake — particularly if you have other traditional IRA money already saved — can create an unexpected tax bill.

Key Takeaways

  • A backdoor Roth involves contributing to a traditional IRA, then immediately converting it to a Roth IRA, bypassing income limits that block direct Roth contributions.
  • You must report the conversion on Form 8606 when you file taxes, and you will owe income tax on any pre-tax money in the account at the time of conversion.
  • If you have existing traditional IRA, SEP IRA, or SIMPLE IRA balances, the IRS treats all your IRAs as one pool for tax purposes, which can create a large tax bill you did not expect.
  • The conversion itself is free, but the tax liability depends on how much pre-tax money you already have in any traditional IRA account.

The two-step process: contribution, then conversion

Step one is straightforward: you open or use an existing traditional IRA and contribute money to it. For 2024, you can contribute up to $7,000 per year (or $8,000 if you are 50 or older). A traditional IRA has no income limits, so anyone can contribute regardless of earnings.

Step two happens immediately after. You contact your IRA custodian (the bank or brokerage holding the account) and request a conversion of that money from the traditional IRA to a Roth IRA. The custodian processes this conversion, and the money moves to your Roth account. You report the conversion on Form 8606 when you file your tax return.

The timing matters. Some people contribute in early January and convert within days. Others wait until after they file taxes the following year. The key is that the conversion must happen in the same tax year as the contribution for the strategy to work cleanly. If you contribute in 2024 and convert in 2025, you will have to report both the contribution and the conversion on your 2024 taxes, which complicates things.

Why the pro-rata rule creates a tax surprise

The biggest trap in a backdoor Roth is the pro-rata rule. When you convert money from a traditional IRA to a Roth, the IRS looks at all your traditional IRA accounts — not just the one you are converting from. It treats them as a single pool for tax purposes.

Here is how it works: if you have $50,000 in a traditional IRA from an old 401(k) rollover, and you contribute $7,000 to a new traditional IRA and convert it, the IRS does not let you convert only the $7,000 you just put in. Instead, it calculates what percentage of your total IRA balance is pre-tax money (money that was never taxed). You owe income tax on that same percentage of the $7,000 you converted.

Example: You have $50,000 in pre-tax traditional IRA money. You contribute $7,000 to a traditional IRA and convert it. Your total is now $57,000. The pre-tax percentage is $50,000 ÷ $57,000 = 88%. You owe income tax on 88% of the $7,000 converted, which is $6,160. Only $840 goes into the Roth tax-free.

This rule applies to traditional IRAs, SEP IRAs, and SIMPLE IRAs. It does not apply to 401(k)s, 403(b)s, or other employer plans. If you have an old 401(k) with pre-tax money, you should roll it into your employer's current 401(k) plan (if allowed) before doing a backdoor Roth, to remove it from the pro-rata calculation.

What you owe in taxes and when you pay it

You owe income tax on the converted amount at your ordinary income tax rate. If you convert $7,000 and the pro-rata rule means $6,000 of it is taxable, and your tax bracket is 24%, you owe $1,440 in federal income tax on that conversion. You may also owe state income tax depending on where you live.

You do not pay this tax when you convert. Instead, you report it on Form 8606 (Part II) when you file your tax return for the year of the conversion. The tax is due when you file, just like any other income tax. If you do not have the cash to pay it, you can pay it from your regular income, but you cannot use money from the IRA itself.

Some people pay the tax from a separate savings account so the full $7,000 (or whatever amount they contributed) ends up in the Roth. Others let the tax liability reduce their refund or increase what they owe. Either way, the tax is separate from the conversion itself.

Who should consider a backdoor Roth and who should avoid it

A backdoor Roth makes sense if you earn too much to contribute directly to a Roth IRA and you want to save money in a Roth account for tax-free growth. It is most useful for high earners who do not have significant pre-tax IRA balances already.

You should avoid a backdoor Roth if you have a large balance in a traditional IRA, SEP IRA, or SIMPLE IRA from a previous job or rollover. The pro-rata rule will create a tax bill that may outweigh the benefit. In that case, you might instead look at a Roth conversion of your entire traditional IRA balance (if you can afford the tax), or explore whether your employer's 401(k) plan allows Roth contributions or in-service conversions.

If you are self-employed or a business owner, a SEP IRA or Solo 401(k) may offer better options than a backdoor Roth. A Solo 401(k) with a Roth option, for instance, lets you make Roth contributions without the pro-rata rule getting in the way.

The paperwork: Form 8606 and what your custodian handles

Your IRA custodian (your bank or brokerage) handles the conversion itself. They move the money from the traditional IRA to the Roth IRA and send you a confirmation. They also send Form 1099-R to you and the IRS, reporting the conversion amount.

You are responsible for filing Form 8606 with your tax return. This form tells the IRS how much you converted, how much of it was pre-tax, and how much was after-tax (if any). Part I of the form covers non-deductible contributions to traditional IRAs. Part II covers conversions. You must file it even if you do not owe tax on the conversion, or the IRS may assess penalties.

Keep records of your contribution and conversion for at least three years. If you contributed after-tax money to the traditional IRA before converting, you will need to show proof that you already paid tax on it, so the IRS does not tax it again.

Timing: when to do a backdoor Roth and when to wait

Most people do a backdoor Roth in January or early February, right after the new year. This gives you the full year to let the money grow in the Roth before you have to report it on taxes. It also gives you time to correct any mistakes before filing.

If you are unsure whether you will have a large bonus or other income that year, you might wait until late in the year when you know your final income. However, waiting until December means you have only a few weeks to complete the conversion before the tax year ends, which can be tight if your custodian is slow.

Some people do multiple backdoor Roths in a single year if they have the cash. You can contribute and convert up to $7,000 per person per year (or $8,000 if 50 or older). If you are married and both spouses have income above the Roth limit, you can each do a backdoor Roth in the same year.

Frequently Asked Questions

Is a backdoor Roth legal?

Yes. The IRS acknowledges backdoor Roths in its own guidance and does not prohibit them. Congress has discussed closing the strategy, but as of now it remains available. Doing a backdoor Roth is not tax evasion or fraud — it is a recognized tax strategy.

What happens if I have a 401(k) from a previous job?

A 401(k) does not trigger the pro-rata rule. Only traditional IRAs, SEP IRAs, and SIMPLE IRAs count. If you have an old 401(k), you can leave it where it is or roll it to your current employer's plan (if allowed). Rolling it out of an IRA avoids the pro-rata problem entirely.

Can I undo a backdoor Roth if I make a mistake?

Yes, but only within a limited window. You can recharacterize a conversion (treat it as if it never happened) by October 15 of the year after the conversion. After that deadline, the conversion is permanent. If you made a mistake with the pro-rata calculation, you may owe additional tax, but you cannot reverse it.

Do I have to do a backdoor Roth every year?

No. A backdoor Roth is optional. You can do one in some years and skip others depending on your income and cash flow. There is no requirement to do it annually, though many high earners do because they want to maximize Roth savings each year.

What if my income drops below the Roth limit partway through the year?

If your income ends up below the limit for direct Roth contributions, you can contribute directly to a Roth instead of using a backdoor. You do not have to do a backdoor Roth if you do not need to. However, if you have already done the backdoor conversion, it is done — you cannot undo it just because your income changed.