What Is A Backdoor Roth IRA And How Does It Work

A backdoor Roth IRA is a strategy for high earners to bypass Roth IRA income limits by making a non-deductible contribution to a Traditional IRA and then converting that money to a Roth IRA. It works because there are no income limits on Roth conversions, but you must handle the pro-rata rule carefully to avoid unexpected taxes.

The backdoor Roth IRA two-step transaction

This maneuver is entirely legal and widely used by individuals whose modified adjusted gross income exceeds the annual thresholds published by the IRS, which the agency sets at $161,000 for single filers or $240,000 for married couples filing jointly for the 2025 tax year; always confirm the current year’s figures directly on the official IRS website.

The mechanics are straightforward. First, you open or use an existing conventional IRA and contribute the maximum annual amount, which the Internal Revenue Service establishes at $7,000 for 2025, plus an extra $1,000 if you are age 50 or older, as a non-deductible input. You do not claim a tax deduction for this funding on your return. Second, you convert that entire standard IRA balance to a Roth IRA. The conversion should happen as soon as possible after the input, ideally within a day or two, before any investment gains accrue. If you wait, even a small gain will be taxable when converted. Most brokerage platforms, such as Vanguard, Fidelity, or Schwab, offer a “Convert to Roth” option in their online account dashboard. Select the standard IRA account, input the amount you just contributed, and confirm the conversion. The money moves into your Roth IRA, where it can grow tax-free and be withdrawn tax-free in retirement, subject to the 5-year rule for earnings.

The pro-rata rule pitfall

The biggest trap is the pro-rata rule, which applies when you have any pre-tax money in any standard IRA, SEP IRA, or SIMPLE IRA. The IRS treats all your classic IRA balances as one combined pool, regardless of which account holds them. If you hold a pre-tax IRA balance of $50,000, based on your own account statements, and you make a $7,000 non-deductible addition, then convert $7,000 to a Roth, the IRS considers 87% of the conversion ($50,000 ÷ $57,000) to be taxable pre-tax money. This can trigger a large, unexpected tax bill, making the backdoor strategy nearly useless unless you eliminate the pre-tax balances first. The fix is to roll those pre-tax IRA balances into a 401(k), 403(b), or governmental 457(b) plan that accepts rollovers from iras. If your employer’s plan allows it, you can move the pre-tax money into the workplace plan before year-end, leaving only the non-deductible basis in your classic IRA. A related resource, the rollover pension to IRA article, explains how to move pension lump sums into an IRA, but for the backdoor Roth, you are doing the reverse, moving IRA money into a 401(k) to avoid the pro-rata rule.

Reporting the backdoor Roth on your taxes

Correct tax reporting is essential to avoid double taxation. You must file Form 8606 with your annual tax return. Part I of the form records the non-deductible classic IRA addition, your “basis.” You enter the funding amount, note that it is non-deductible, and carry the basis forward. Then, Part II reports the Roth conversion, showing the total amount converted and the taxable portion. If you convert immediately with no gains, the taxable amount is zero, and the basis is fully applied. If you fail to file Form 8606, the IRS may treat the entire conversion as taxable income, effectively taxing your after-tax money a second time. Tax software like TurboTax or H&R Block will walk you through the steps, but you must explicitly tell the software that the conventional IRA funding was non-deductible. For a deeper understanding of how IRA timing rules affect withdrawals, the IRAs: What to Know and How to Handle It hub provides comprehensive guidance on contribution limits, conversion strategies, and the 5-year rule for Roth accounts.

Unlike a direct Roth contribution, a backdoor Roth IRA legally circumvents the income-eligibility phaseout range by pairing a non-deductible deposit with a conversion, a sequence that cannot be replicated with a standard brokerage account or a pre-tax retirement plan alone.