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Tax Planning

Backdoor Roth IRA: How It Works and the Pro-Rata Trap

A backdoor Roth is a nondeductible traditional IRA contribution converted to Roth. The pro-rata rule makes it taxable if you hold pre-tax IRA money.

Backdoor Roth IRA: How It Works and the Pro-Rata Trap

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What is a backdoor Roth IRA?

  • Earners above the Roth income limits contribute to a traditional IRA without a deduction, then convert it to a Roth IRA.
  • In 2026, direct Roth contributions phase out at MAGI of $153,000–$168,000 single and $242,000–$252,000 joint.
  • The 2026 IRA limit is $7,500, plus $1,100 at age 50 or older.
  • Traditional IRA contributions and Roth conversions have no income limits.
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Mega Backdoor Roth: Turning After-Tax 401(k) Money Into Roth SavingsRoth IRA Rules and LimitsTraditional IRA Deduction Rules

Full Guide

What is a backdoor Roth IRA?

  • Earners above the Roth income limits contribute to a traditional IRA without a deduction, then convert it to a Roth IRA.
  • In 2026, direct Roth contributions phase out at MAGI of $153,000–$168,000 single and $242,000–$252,000 joint.
  • The 2026 IRA limit is $7,500, plus $1,100 at age 50 or older.
  • Traditional IRA contributions and Roth conversions have no income limits.

How does the pro-rata rule work?

  • The taxable share of a conversion depends on the mix of pre-tax and after-tax money across all your traditional, SEP, and SIMPLE IRAs.
  • The calculation uses your IRA balances on December 31 of the conversion year, not on the day you convert.
  • You can't convert only the after-tax dollars while pre-tax IRA money exists.
  • Each spouse's IRAs are counted separately, and 401(k) and 403(b) balances aren't included.

How can you avoid a pro-rata tax bill?

  • If your employer plan accepts roll-ins, moving pre-tax IRA money into it before year-end removes it from the calculation.
  • Rolling in trades IRA investment choices for the plan's menu, fees, and rules.
  • Converting all pre-tax IRA money is another route, but it creates taxable income now.
  • A SEP or SIMPLE IRA from side self-employment counts in the calculation, which often surprises people.

What paperwork does it require?

  • Form 8606 reports each year's nondeductible contribution and tracks your after-tax basis.
  • The same form reports the conversion and calculates its taxable portion.
  • Skipping Form 8606 risks paying tax twice on the same dollars and carries a $50 penalty.
  • Earnings between contribution and conversion are taxable when converted.

Is the backdoor Roth allowed?

  • Each step, a nondeductible contribution and a conversion, is permitted by statute.
  • The conference report on the 2017 tax law described this two-step approach as available to higher earners.
  • Proposals to restrict it have been introduced in Congress, and none had been enacted as of September 2026.
  • Each conversion starts its own five-year clock for the 10% penalty on converted amounts withdrawn before 59½.

How is it different from a mega backdoor Roth?

  • The mega backdoor uses after-tax 401(k) contributions, converted to Roth inside the plan or rolled to a Roth IRA.
  • It requires a plan that allows after-tax contributions and in-plan conversions or in-service withdrawals.
  • Total 2026 contributions to a 401(k) from all sources can't exceed $72,000, not counting catch-ups.
  • Both strategies can be used in the same year when the plan permits.

Key takeaways

  • The backdoor Roth pairs a nondeductible IRA contribution with a Roth conversion.
  • Pre-tax IRA balances on December 31 drive the pro-rata tax.
  • File Form 8606 every year you make a nondeductible contribution.
  • Confirm execution and reporting with your CPA.
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Related Topics

Tax Planning

Mega Backdoor Roth: Turning After-Tax 401(k) Money Into Roth Savings

A mega backdoor Roth uses after-tax 401(k) contributions, then converts them to Roth; in 2026 the total plan cap is $72,000 before catch-ups.

Retirement Planning

Roth IRA Rules and Limits

For 2026, you can put $7,500 in a Roth IRA ($8,600 at 50+) if MAGI is below $153,000 single or $242,000 joint; qualified withdrawals are tax-free.

Retirement Planning

Traditional IRA Deduction Rules

For 2026, you can contribute $7,500 ($8,600 at 50+) to a traditional IRA; the deduction phases out by income only if you or a spouse has a workplace plan.

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