Backdoor Roth IRA

A two-step strategy that allows high earners who exceed the Roth IRA income limits to fund a Roth IRA indirectly — by making a non-deductible traditional IRA contribution and then converting it to Roth.

The backdoor Roth IRA is a legal workaround for the Roth IRA income limits. Direct Roth IRA contributions are phased out for single filers with MAGI above $146,000 and eliminated above $161,000 (2024); for married filing jointly, the phase-out runs from $230,000 to $240,000. High earners above these limits cannot contribute directly to a Roth IRA. The backdoor strategy circumvents this: you make a non-deductible contribution to a traditional IRA (no income limits apply), then immediately convert that traditional IRA to a Roth IRA. The conversion is a taxable event only on the pre-tax portion — and since the contribution was non-deductible (after-tax), there's ideally nothing to tax.

The mechanics are straightforward in isolation but complicated by the pro-rata rule. When you convert a traditional IRA to Roth, the IRS looks at all your traditional, SEP, and SIMPLE IRA balances combined — not just the account you contributed to. If you have $90,000 in a pre-tax traditional IRA and add $7,000 in a non-deductible contribution ($97,000 total), only 7.2% of any conversion ($7,000/$97,000) is tax-free. The remaining 92.8% is taxable as ordinary income at conversion. The pro-rata rule effectively negates the backdoor strategy if you have significant pre-tax IRA balances.

The cleanest backdoor Roth setup requires zero pre-tax IRA balances. To achieve this: either roll any existing traditional IRA balances into a current employer's 401(k) (if the plan accepts incoming rollovers — not all do) before making the backdoor contribution, or convert the entire traditional IRA to Roth in a year when you have low income. Once pre-tax IRA balances are cleared, contribute the annual maximum ($7,000 for 2024, $8,000 if age 50+) to a traditional IRA as a non-deductible contribution, wait a brief period (some advisors recommend days to a month — there is no required waiting period), then convert to Roth.

The backdoor Roth must be properly documented on your tax return to avoid double-taxation. You file Form 8606 each year you make a non-deductible IRA contribution, establishing your 'basis' in the traditional IRA (the after-tax amount). When you convert, you again file Form 8606 to report the conversion and show that the basis offsets the taxable portion. Failing to track basis via Form 8606 can result in the IRS treating your Roth conversion as fully taxable — paying tax on money you already paid tax on. Keeping Form 8606 records indefinitely is essential.

Step-by-Step Process

  • Step 1: Confirm you have no pre-tax IRA balances (traditional, SEP, or SIMPLE IRA) — or plan to clear them before proceeding.
  • Step 2: Open a traditional IRA at a brokerage if you don't have one. Contribute the maximum non-deductible contribution ($7,000/$8,000 for 2024).
  • Step 3: Keep the contribution in cash (money market) within the traditional IRA — this avoids the complication of gains that would be partially taxable at conversion.
  • Step 4: Wait for the contribution to settle (typically 1-3 business days).
  • Step 5: Initiate a Roth conversion of the traditional IRA balance to a Roth IRA (same brokerage or a different institution).
  • Step 6: File Form 8606 with your tax return for the contribution year (reporting basis) and the conversion year (reporting the conversion as tax-free due to basis).
  • Repeat annually: the backdoor is a year-by-year strategy — the contribution and conversion happen each year you're over the income limit.

The Pro-Rata Rule

  • The pro-rata rule: when you convert, the IRS aggregates ALL your traditional IRA accounts (including SEP and SIMPLE IRAs) to determine what fraction of your conversion is pre-tax vs after-tax.
  • Example: $100,000 pre-tax rollover IRA + $7,000 non-deductible contribution = $107,000 total. Fraction that is after-tax: $7,000 / $107,000 = 6.5%. Only 6.5% of any conversion is tax-free; the rest is ordinary income.
  • Workaround: roll pre-tax IRA balances into a current employer 401(k) before doing the backdoor — this removes them from the IRA aggregation, clearing the pro-rata issue.
  • If you can't roll over to a 401(k): consider doing a full Roth conversion of all pre-tax IRA balances in a low-income year — pay the tax once and clear the deck for future backdoor contributions.
  • Roth IRA conversions don't create pro-rata issues for future backdoor contributions — only pre-tax balances in traditional/SEP/SIMPLE IRAs matter.

Backdoor Roth vs Regular Roth Contribution

  • Same result: once the conversion is complete, the money is in a Roth IRA with the same tax-free growth and withdrawal rules as a direct Roth contribution.
  • Same contribution limits: the backdoor doesn't provide additional contribution room beyond the annual IRA limit — it's just an alternative path to get there.
  • Administrative overhead: the backdoor requires tracking Form 8606, managing IRA balances to avoid pro-rata issues, and understanding conversion mechanics — it's more complex than a direct contribution.
  • Congressional scrutiny: the backdoor Roth has periodically been targeted by tax reform proposals; as of 2024 it remains legal, but its future is uncertain — front-loading Roth contributions while the strategy is available is prudent.

Example

A software engineer earns $230,000 MAGI — above the Roth IRA phase-out. She has no pre-tax IRA balances (her prior 401(k) rollover went into her current employer's 401(k)). In January, she contributes $7,000 to a traditional IRA (non-deductible — she can't deduct it because she's also covered by a workplace retirement plan). The contribution sits in a money market fund. Three days later, she converts the entire $7,000 to a Roth IRA. Since the only balance was her non-deductible contribution, the conversion is tax-free (basis = $7,000, taxable amount = $0). She files Form 8606 with her return. Next January, she repeats the process.