Backdoor Roth IRA: How It Works, Step by Step

If you earn too much to contribute directly to a Roth IRA (for 2026, that means a Modified Adjusted Gross Income above $168,000 for single filers or $252,000 for married couples filing jointly, subject to change), the backdoor Roth IRA is a legal conversion strategy that gives you an indirect path to the same benefits. You contribute to a traditional IRA on an after-tax basis, then convert those dollars to a Roth IRA. From that point forward, the money grows tax-free.

The conversion itself is not complicated. However, one tax rule, the pro-rata rule, can significantly change the math depending on what is already sitting in your traditional IRA accounts. That planning detail is where the real value of understanding this strategy comes in, and it is the piece we will spend the most time on below.

One important distinction before we get into the steps: a backdoor Roth IRA is not the same as the mega backdoor Roth strategy, which involves after-tax contributions to your employer’s 401(k) plan and significantly higher contribution limits. The regular backdoor Roth uses your personal IRA accounts, and you can execute it regardless of what your employer’s retirement plan offers.

How the Backdoor Roth IRA Works, Step by Step

The backdoor Roth involves three steps, and none of them are particularly complex on their own.

Step 1: Contribute to a traditional IRA. You make a non-deductible, after-tax contribution to a traditional IRA. For 2026, the contribution limit is $7,500, or $8,600 if you are age 50 or older (subject to change). There are no income limits on making non-deductible traditional IRA contributions. 

Step 2: Convert to a Roth IRA. You convert that traditional IRA balance to a Roth IRA. There are no income limits on Roth conversions, and there is no cap on the amount you can convert. Because you contributed after-tax dollars and are converting before significant earnings accumulate, the tax impact of the conversion itself can be minimal, provided you do not have other pre-tax IRA balances. (More on that in the next section.)

Step 3: Report the contribution and conversion on your tax return. You track the non-deductible contribution on IRS Form 8606 and report the conversion when you file. This documentation is important because it is how your CPA confirms you are not taxed again on dollars you have already paid taxes on. The IRS guidelines on IRA contributions outline the current limits and reporting requirements.

The timing between Steps 1 and 2 can be as short as a few days. Many people complete the contribution and conversion within the same week, because the goal is to convert before the traditional IRA balance generates meaningful earnings. Any earnings that do accumulate before conversion would be taxable.

The Pro-Rata Rule: The Planning Detail That Can Change the Math

The three steps above are straightforward in isolation. But there is one tax rule that can significantly complicate the outcome, and it is the reason the backdoor Roth does not work equally well for everyone: the pro-rata rule.

The IRS treats all of your traditional IRA accounts (traditional, rollover, SEP, and SIMPLE IRAs) as a single pool when calculating the tax impact of any conversion. If you have existing pre-tax balances in any of those accounts, you cannot simply convert just your new non-deductible contribution and avoid taxes. The taxable and non-taxable portions of your conversion are determined proportionally based on your total IRA balance.

Consider a hypothetical scenario: you have $200,000 in a rollover IRA from a previous employer, all of which is pre-tax money. You contribute $7,500 to a new traditional IRA on an after-tax basis with the intention of executing a backdoor Roth conversion. Your total traditional IRA balance is now $207,500, and your after-tax basis is $7,500, roughly 3.6% of the total. Under the pro-rata rule, only about 3.6% of your $7,500 conversion (approximately $270) would be tax-free. The remaining $7,230 would be taxable as ordinary income. That largely defeats the purpose of the strategy.

The planning move: If your employer’s 401(k) plan accepts incoming rollovers (and many do), you may be able to roll your pre-tax IRA balances into the 401(k) before executing the backdoor Roth. This removes the pre-tax dollars from the IRA pool, which means your new after-tax contribution can be converted with little to no tax impact. This is not an option for everyone, but it can be one of the most effective ways to make the backdoor Roth work if you have accumulated pre-tax IRA balances over the course of your career.

All of this to say: the backdoor Roth can be a meaningful strategy, but it works best when your traditional IRA landscape is either empty or can be consolidated into an employer plan first. Your tax professional and wealth advisor can help you evaluate whether this step makes sense before you execute.

Is the Backdoor Roth IRA Going Away?

This is one of the most common questions we hear, and it is understandable. Over the past several years, Congress has proposed legislation that would have eliminated or restricted the backdoor Roth strategy. The Build Back Better Act in 2021, for example, included provisions that would have closed this pathway for higher-income taxpayers.

Those provisions did not become law. The One Big Beautiful Bill Act (OBBBA), signed in 2025, focused primarily on making the individual income tax rates under the Tax Cuts and Jobs Act permanent. It did not include any restrictions on backdoor Roth conversions. As of 2026, the strategy remains fully legal and available.

That said, tax law is always subject to change, and future legislation could revisit this at any time. This is one reason many tax professionals encourage acting on what the current tax code allows rather than waiting to see what might change. We do not know what tax policy will look like in the future, but we know what it looks like now, and the backdoor Roth remains part of it.

Is a Backdoor Roth Worth It?

The answer depends almost entirely on your specific tax situation, and particularly on whether the pro-rata rule creates a meaningful tax cost for you.

When it can make strong sense: If you have little to no pre-tax money in traditional IRAs — or you can roll those balances into a 401(k) — the backdoor Roth is one of the most direct ways to continue building tax-free retirement dollars each year. Over a 20-year period, $7,500 in annual contributions compounding tax-free can add up to meaningful wealth, and the long-term benefit is amplified by the fact that Roth IRAs are not subject to required minimum distributions.

When the math gets more complicated: If you have significant pre-tax IRA balances that cannot be moved into an employer plan, the pro-rata rule can erode much of the tax advantage. In those situations, the cost of conversion may not justify the long-term Roth benefit, depending on your current tax bracket and your expected bracket in retirement. This is where the analysis becomes very specific to your numbers.

There are also other paths to Roth dollars worth considering alongside the backdoor strategy. Roth 401(k) contributions have no income restrictions and allow significantly larger annual contributions, up to $24,500 for 2026, plus catch-up amounts for eligible participants (subject to change). If your employer plan offers a Roth option, that can be a more direct path with fewer moving parts. And depending on your broader financial picture, Roth conversions during lower-income years, converting leftover 529 funds to a Roth IRA under the SECURE 2.0 Act, and the wider set of tax strategies for high-income earners may also play a role in your overall plan.

For a deeper look at the specific pros, cons, and risks of the backdoor Roth strategy, we will be publishing a dedicated guide later this year.

Backdoor Roth vs. Mega Backdoor Roth

Because the two terms are often used interchangeably (and they should not be), here is a brief comparison:

The mega backdoor Roth allows for substantially higher contributions, but the reality is that many employer plans do not support it. We wrote a detailed breakdown of the mega backdoor Roth strategy and why it rarely works in practice.

What to Do Next

The backdoor Roth IRA can be a valuable piece of a broader tax planning strategy, but whether it fits your situation depends on the specifics — your current IRA balances, your income trajectory, your employer plan options, and how the pro-rata rule applies to you. These are exactly the kinds of planning details that benefit from a conversation with someone who sees your full financial planning picture.

For more context on Roth conversion strategies and common mistakes to avoid, watch our discussions on Off the Wall and this episode on Roth IRA planning, or listen to What People Get Wrong About Roth IRAs and Conversions on the Between Sips podcast (Spotify).

At Monument, we work with high-achieving professionals navigating these decisions every day. If you are wondering whether a backdoor Roth belongs in your strategy — or if there is a more effective path to the same goal — let’s talk. Our complimentary Wealth Check is a great place to start.

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