What is a Backdoor Roth IRA?

A Backdoor Roth IRA is not a special account type. It is a two-step maneuver that lets high earners fund a Roth IRA despite exceeding the income limits: contribute to a traditional IRA on a nondeductible basis, then convert that balance to a Roth IRA. Conversions have no income limit, so the front door being closed does not matter.

The strategy exists because of an inconsistency in the tax code. Congress removed the income cap on Roth conversions in 2010 but left the cap on direct Roth contributions in place, which made the workaround available to anyone willing to do the paperwork.

Backdoor Roth IRA Income Limits for 2026

Direct Roth IRA contributions phase out over a range of modified adjusted gross income (MAGI). For 2026:

Below the range you can contribute directly and have no reason to use the backdoor. Inside the range your allowed contribution is reduced. Above it, direct contributions are barred entirely, and the backdoor is the way to fund a Roth IRA. A Mega Backdoor Roth through your 401(k), if your plan allows after-tax contributions, is a separate route to Roth savings that doesn’t depend on IRA rules at all.

The 2026 IRA contribution limit is $7,500, plus a $1,100 catch-up if you are 50 or older. Those limits apply to the contribution step, so the backdoor moves the same amount a direct contribution would.

How to Do a Backdoor Roth IRA, Step by Step

1. Contribute to a traditional IRA and do not deduct it. If you or your spouse is covered by a retirement plan at work, the deduction phases out at incomes no higher than the Roth limits, so at backdoor-level income it isn’t available. If neither of you is covered, the contribution is deductible at any income, and you would choose to treat it as nondeductible on Form 8606 instead.
2. Convert to a Roth IRA. Ask your IRA custodian to convert the balance; the custodian reports it on Form 1099-R.

Then there is the paperwork, which is not optional. File Form 8606 for both the year of the contribution and the year of the conversion. It records your after-tax basis, which keeps the same dollars from being taxed twice; without it, the conversion can be taxed as if it were all pre-tax money.

Because the contribution was already after-tax, converting it produces little or no additional tax. Any investment earnings between contribution and conversion are taxable, so converting promptly, with the money held in cash in between, keeps the tax near zero.

The Pro-Rata Rule Is the Catch

The IRS does not let you choose which dollars you convert. Under the pro-rata rule, every conversion is treated as coming proportionally from all your traditional, SEP, and SIMPLE IRA balances combined. Form 8606 measures that pool as your total IRA balance on December 31 of the conversion year plus any distributions and conversions you made during the year, so converting everything before year-end doesn’t escape the rule. Employer 401(k) balances are excluded.

Say you have $93,000 in a rollover IRA from an old 401(k), all pre-tax, and you contribute $7,500 nondeductible intending a clean backdoor conversion. Your total IRA balance is $100,500, of which $7,500 (7.5%) is after-tax basis. Converting $7,500 means only about $560 comes out tax-free. The remaining $6,940 is taxable income, and you still carry basis forward on the rest.

The usual fix is to eliminate the pre-tax IRA balance before converting, typically by rolling it into your current employer’s 401(k) if the plan accepts incoming rollovers. Since 401(k) balances are invisible to the pro-rata calculation, this restores a clean conversion. The rollover must be completed before December 31 of the conversion year, not merely before the conversion.

Backdoor Roth vs. Mega Backdoor Roth

Similar names, different mechanisms and very different scale.

They are not mutually exclusive. Someone whose plan supports both can do each in the same year.

Is It Legal?

Yes. The concern raised for years was the step transaction doctrine, the idea that the IRS might collapse the contribution and conversion into a single disallowed direct Roth contribution. That has not happened. The conference report accompanying the 2017 tax law explicitly acknowledged the strategy, and there is no statutory waiting period between the two steps.

Legislation to close the backdoor has been proposed and not enacted. That is worth knowing when planning multi-year, since the rule could change.

Frequently Asked Questions

How much can I put into a backdoor Roth? The standard IRA limit, $7,500 for 2026, plus $1,100 if you are 50 or older. The backdoor changes how you get the money in, not how much.

How long should I wait between contributing and converting? There is no required waiting period, and you can convert as soon as the contribution settles. Waiting longer only creates taxable earnings on the contribution.

What if I already have a large traditional IRA? The pro-rata rule will make most of your conversion taxable. Roll the pre-tax balance into an employer 401(k) before December 31 of the conversion year if your plan accepts it, or reconsider the strategy.

Do I need to file anything? Form 8606, for both the contribution year and the conversion year. The form is the record of your after-tax basis, and skipping it can mean paying tax twice on the same dollars.

Can I do a backdoor Roth for my spouse? Yes. Each spouse uses their own IRA, and a non-working spouse can contribute through a spousal IRA based on household earned income. Pro-rata is calculated per person, not jointly.

Does a backdoor Roth conversion have a five-year clock? Mostly no. Under Internal Revenue Code (IRC) Section 408A(d)(3)(F), the five-year rule on conversions only recaptures the 10% early-withdrawal penalty on the portion of a conversion that was taxable. A clean backdoor conversion is almost entirely nondeductible basis that was never taxed on conversion, so withdrawing it within five years doesn’t trigger the penalty. Any taxable portion, such as earnings converted along with the contribution or pre-tax IRA money pulled in by the pro-rata rule, does carry its own five-year period if you are under 59 1/2.