Direct Roth IRA contributions are phased out for single filers with modified adjusted gross income (MAGI) between $150,000 and $165,000, and for married couples filing jointly between $236,000 and $246,000 in 2026. Above those thresholds, you cannot contribute to a Roth IRA directly. The backdoor Roth is a fully legal two-step workaround that has been widely used by high-income earners for over a decade and was explicitly blessed by Congress in a 2018 conference report.
The Two-Step Process
- Make a non-deductible contribution to a traditional IRA. Anyone with earned income can contribute to a traditional IRA regardless of income level -- the income limits only affect deductibility. The 2026 IRA contribution limit is $7,000 ($8,000 if age 50 or older). Because you are above the income threshold for both Roth contributions and deductible traditional IRA contributions (assuming you also have a workplace plan), this contribution goes in after-tax. File Form 8606 with your tax return to record it -- this creates your "basis" and is essential for avoiding double taxation later.
- Convert the traditional IRA to a Roth IRA. After the contribution settles (typically a few business days), initiate a Roth conversion. Since you already paid tax on the contribution (it was non-deductible), only earnings that accumulated between contribution and conversion are taxable. If you convert quickly, earnings are minimal and the taxable amount rounds to near zero.
The Pro-Rata Rule: The Most Important Trap
The backdoor Roth works cleanly only if you have no pre-tax money in any traditional IRA, including SEP-IRAs and SIMPLE IRAs. If you do have pre-tax IRA balances, the pro-rata rule applies -- and it can make the conversion significantly taxable.
How the pro-rata rule works: The IRS looks at your total IRA balance across all traditional IRAs at year-end, not just the account you are converting from. The taxable percentage of your conversion equals the pre-tax portion of your total IRA balance.
Example: You contribute $7,000 non-deductible to a new traditional IRA. But you also have $63,000 in a pre-tax rollover IRA from a previous employer's 401(k). Your total IRA balance is $70,000. Pre-tax ratio: $63,000 / $70,000 = 90%. If you convert the $7,000, 90% of it ($6,300) is taxable -- even though you contributed after-tax dollars. You effectively converted mostly pre-tax money in the IRS's view.
The solution: Roll your existing pre-tax IRA funds into your current employer's 401(k) plan before year-end (the December 31 date is the relevant snapshot for pro-rata). Many 401(k) plans accept incoming rollovers -- check with your plan administrator. Once the pre-tax IRA is empty, the backdoor Roth conversion is clean.
Step-by-Step Execution
- Verify you have no pre-tax IRA balances, or solve the pro-rata problem first
- Open a traditional IRA at your brokerage if you do not already have one
- Contribute $7,000 (or $8,000 if 50+) as a non-deductible contribution -- leave it in cash, do not invest it
- Wait for the contribution to settle (typically 1-3 business days)
- Initiate a Roth conversion of the full balance from the traditional IRA to a Roth IRA at the same institution -- most brokerages allow this online
- File Form 8606 (Part I and Part II) with your tax return for the year of the contribution and conversion
How to Report It on Your Tax Return
- Form 8606, Part I: Reports your non-deductible contribution and establishes your IRA basis
- Form 8606, Part II: Reports the Roth conversion and calculates the taxable amount (should be near zero if done correctly)
- Form 1099-R: Your IRA custodian will send this showing the conversion. Box 2a (taxable amount) may show the full amount -- do not panic. Form 8606 overrides this on your return
- Form 5498: Confirms the Roth conversion was received -- typically issued the following May
The most common and costly mistake: skipping Form 8606 because you think "I already paid tax on it." Without Form 8606 on file for every year you made a non-deductible contribution, the IRS has no record of your basis. When you take Roth distributions years later, they may appear fully taxable. File Form 8606 every year you execute a backdoor Roth, even if you owe no additional tax.
Mega Backdoor Roth: The 401(k) Version
Some 401(k) plans allow a related strategy called the mega backdoor Roth. If your plan permits after-tax (non-Roth) contributions above the standard $23,500 employee deferral limit, and also allows in-service withdrawals or in-plan Roth conversions, you can contribute up to the total 415 limit ($70,000 in 2026) and convert the after-tax portion to Roth. Not all plans allow this -- check your plan documents or contact your HR department.
2026 Roth IRA Income Limits for Reference
If your MAGI is below the phase-out range, you can skip the backdoor entirely and contribute directly. For 2026, direct Roth contributions are fully allowed below $150,000 (single) and $236,000 (married filing jointly). See the full Roth IRA income limits guide for the complete phase-out calculation.
Source
IRS Publication 590-A (Contributions to Individual Retirement Arrangements); IRS Form 8606 instructions; IRS Notice 2014-54 (after-tax rollover rules); Joint Committee on Taxation, JCX-67-17 (2018 conference report acknowledging backdoor Roth).
Timing: When to Execute the Backdoor Roth
Many financial advisors recommend doing the contribution and conversion in the same tax year and as close together as possible -- ideally within days of each other. Letting the non-deductible IRA contribution sit invested for months before converting means the account may have accumulated gains, which become taxable on conversion. Converting quickly keeps the taxable amount as close to zero as possible.
Some taxpayers spread the contribution and conversion across different calendar years to simplify bookkeeping. This is legal but requires careful tracking. If you contribute in December 2026 and convert in January 2027, you report the non-deductible contribution on your 2026 Form 8606 and the conversion on your 2027 Form 8606. The basis established in 2026 carries forward to offset the 2027 conversion.
Does the Backdoor Roth Still Work Under Current Law?
As of 2026, yes. The backdoor Roth has survived multiple rounds of legislative proposals that would have eliminated it, most notably the Build Back Better Act in 2021. Congress has not enacted restrictions on the strategy. The 2018 conference report explicitly acknowledged the backdoor Roth as an accepted practice. There is no guarantee the strategy will remain available indefinitely, which is a reason to use it while it exists. If your income exceeds Roth contribution limits and you are not currently doing backdoor Roth conversions, you are leaving a significant tax advantage unclaimed.
Common Backdoor Roth Mistakes
Beyond the pro-rata rule, several other errors trip up first-time backdoor Roth executions. Investing the non-deductible contribution before converting is a common one -- if your $7,000 grows to $7,200 before you convert, $200 is taxable. Convert quickly while the funds are in cash to minimize this. Another mistake: making the contribution to the wrong account. The non-deductible contribution must go into a traditional IRA, not directly into the Roth. Depositing directly into the Roth without going through the traditional IRA step is a direct Roth contribution and counts against the income limits.
State tax treatment is another consideration that many taxpayers overlook. Most states follow federal tax treatment for IRA conversions, but a handful do not. Some states do not recognize the basis established by non-deductible contributions, meaning the conversion may be partially taxable at the state level even if it is tax-free federally. Check your state's rules before assuming the conversion is also state-tax-free.