The Roth IRA is one of the most powerful accounts available to investors. Everything inside it grows completely tax-free, and you pay nothing on withdrawals in retirement. The problem is that the IRS restricts who can contribute based on income, and a lot of people earn too much to use it the normal way.

In 2026, the ability to contribute directly to a Roth IRA phases out for single filers earning between $153,000 and $168,000, and disappears entirely above $168,000. For married couples filing jointly, the phase-out runs from $242,000 to $252,000.

The backdoor Roth IRA is the legal workaround. It has been widely used since 2010, Congress is aware of it, and it is explicitly legal. Here is exactly how it works.

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The core idea: There is no income limit on contributing to a Traditional IRA without a deduction, and no income limit on converting a Traditional IRA to a Roth IRA. The backdoor Roth combines those two steps to get money into a Roth regardless of your income.

Who needs this

If your income is below the phase-out threshold, just contribute directly to a Roth IRA. The backdoor strategy is only necessary if you earn above $153,000 as a single filer or $242,000 as a married couple filing jointly in 2026. If you are in that situation, the backdoor gives you access to the same tax-free growth that lower earners get through the front door.

The two steps

1
Contribute to a Traditional IRA without taking the deduction
Open a Traditional IRA if you do not already have one and contribute up to the 2026 limit of $7,500 (or $8,600 if you are 50 or older). Use after-tax dollars. Do not claim a deduction on your taxes for this contribution. This is called a non-deductible IRA contribution, and it creates what the IRS calls "basis" in your IRA, meaning the IRS already knows this money has been taxed.
2
Convert the Traditional IRA to a Roth IRA
Log into your brokerage account and initiate a Roth conversion. Most major brokerages, Fidelity, Vanguard, Schwab, let you do this entirely online in a few minutes. The money moves from your Traditional IRA into your Roth IRA. Do this as quickly as possible after the contribution, ideally within days. The longer you wait, the more any investment gains accumulate and become taxable at conversion. If you convert immediately after contributing, there is essentially nothing to tax.

Once the money is in the Roth IRA, it behaves exactly like a direct Roth contribution. It grows tax-free and comes out tax-free in retirement.

The one trap: the pro-rata rule

The backdoor Roth works cleanly only if you have no other pre-tax money sitting in Traditional IRAs, SEP IRAs, or SIMPLE IRAs. If you do, the pro-rata rule kicks in and the conversion becomes partially taxable, sometimes significantly so.

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The pro-rata rule: The IRS treats all your Traditional, SEP, and SIMPLE IRA balances as one combined pool. When you convert, the tax-free portion is calculated as a ratio of after-tax money to total IRA balance. You cannot cherry-pick which dollars you convert.

Here is what this looks like with real numbers. Say you contribute $7,500 to a Traditional IRA in January with after-tax dollars, planning a clean backdoor conversion. But you also have a $92,500 rollover IRA from an old 401(k) sitting at the same brokerage. Your total IRA balance is $100,000, of which only $7,500 is after-tax.

Pro-rata calculation example

After-tax contribution (new) $7,500
Pre-tax rollover IRA balance $92,500
Total IRA balance $100,000
After-tax percentage 7.5%
Tax-free portion of $7,500 conversion $563
Taxable portion of conversion $6,937

Instead of a clean tax-free conversion, you owe ordinary income taxes on $6,937. At a 32% marginal rate, that is over $2,200 in unexpected taxes on a move you thought would cost nothing. This is the single most common mistake people make with the backdoor Roth.

How to neutralize the pro-rata rule

The most effective solution is to roll your pre-tax IRA balances into your current employer's 401(k) before executing the backdoor conversion. Most 401(k) plans accept incoming rollovers. Once the pre-tax IRA money is inside the 401(k), it no longer counts in the pro-rata calculation. Your IRA balance drops to zero, and the next year's backdoor conversion is clean.

If your 401(k) does not accept rollovers, you have fewer clean options. You could convert the entire pre-tax IRA balance in a single year and pay the taxes, which makes sense for some people if they expect their tax rate to rise significantly in the future. Or you could simply skip the backdoor Roth that year and invest in a taxable brokerage account instead, which is a perfectly reasonable alternative.

The paperwork: Form 8606

Every year you make a non-deductible IRA contribution, you must file Form 8606 with your tax return. This form tells the IRS that the contribution was made with after-tax dollars and establishes your basis. Without it, the IRS has no record that the money was already taxed, and the entire conversion could be treated as taxable income. Do not skip this form. Your tax software will prompt you for it if you answer the questions correctly.

Deadlines

You have until April 15, 2027 to make your 2026 Traditional IRA contribution. However, the conversion itself must be completed by December 31, 2026 to count as a 2026 conversion. Most people contribute and convert in the same transaction or within days of each other to minimize any taxable gains that accumulate between the two steps.

The quick version

  • Direct Roth IRA contributions phase out above $153,000 (single) and $242,000 (married) in 2026
  • The backdoor Roth is legal, widely used, and works regardless of income
  • Step 1: contribute $7,500 to a Traditional IRA without taking a deduction
  • Step 2: convert the Traditional IRA to a Roth IRA immediately
  • The pro-rata rule makes the conversion partially taxable if you have other pre-tax IRA balances
  • Fix the pro-rata problem by rolling pre-tax IRA money into your 401(k) first
  • Always file Form 8606 to document your non-deductible contribution

This is one of the few strategies in personal finance where the people who earn more actually have to do more work to access the same benefit. But the tax-free compounding on the other side is worth it.