Backdoor Roth IRA Step-by-Step for H1B Holders
By WealthyDesis Team · August 6, 2026
A backdoor Roth IRA is really just a nondeductible traditional IRA contribution that you convert to a Roth soon after. It’s a workaround for anyone whose income sits above the direct Roth contribution limit. The mechanics are simple enough, except for one rule that trips up nearly everyone the first time: the pro-rata rule, which taxes your conversion based on all your traditional IRA money, not just what you just put in.
Who actually needs this
For 2026, direct Roth IRA contributions phase out between $153,000 and $168,000 MAGI for single filers, and between $242,000 and $252,000 for married couples filing jointly. Above those numbers, a direct Roth contribution isn’t on the table at all. The backdoor route is the only way in.
Traditional, SEP, or SIMPLE IRA — Rollover 401(k)s don't count here.
Direct Roth IRA eligibility (2026 limits)
—
Backdoor contribution room this year
—
Pro-rata taxable portion of the conversion
—
—
Educational estimate, not tax advice — verify current-year MAGI phase-outs at IRS.gov before filing, and note the pro-rata rule counts every traditional/SEP/SIMPLE IRA you own as of Dec 31, even ones unrelated to this conversion.
The steps
- Check for existing pre-tax IRA money. Add up any traditional, SEP, or SIMPLE IRA balances you hold anywhere, as of December 31 of the year you plan to convert. Zero balance? Skip to step 3, you’re set up for a clean backdoor.
- If you do have pre-tax IRA money, consider rolling it into a 401(k) first. Most employer 401(k) plans accept incoming rollovers from traditional IRAs, and doing this before you convert removes that balance from the pro-rata calculation entirely, since 401(k) balances don’t count toward the IRA aggregation rule.
- Contribute to a nondeductible traditional IRA. The limit is $7,500 for 2026, or $8,600 if you’re 50 or older with the $1,100 catch-up.
- Convert the traditional IRA balance to a Roth IRA. Do it fairly promptly. Any investment growth between the contribution and the conversion is taxable, since only your original nondeductible contribution counts as basis that’s already been taxed.
- File Form 8606 for both the contribution year and the conversion year. This is the paper trail proving to the IRS how much of the money was already taxed.
A worked example — the pro-rata rule in action
Arjun, single, has a rollover traditional IRA worth $50,000 from a 401(k) he consolidated after switching jobs on his way to a green card. His 2026 MAGI is $190,000, well above the Roth phase-out ceiling, so a backdoor Roth is his only route to a Roth IRA.
He contributes $7,500 to a new nondeductible traditional IRA and converts it the same week. The pro-rata rule won’t let him treat that $7,500 in isolation:
- Total IRA money as of Dec. 31: $50,000 pre-tax plus $7,500 new after-tax basis, or $57,500 total.
- Taxable percentage of the conversion: $50,000 ÷ $57,500 = 87%.
- Taxable amount on his $7,500 conversion: 87% × $7,500 = $6,525, taxed as ordinary income.
He ends up owing tax on $6,525 of a $7,500 conversion, nowhere near the clean, tax-free move he expected. Had he rolled that $50,000 into his current employer’s 401(k) before converting (assuming the plan accepts incoming rollovers, and most do), his pro-rata percentage would have dropped to roughly zero, and the conversion would have come in close to tax-free.
Why this is often cleaner for immigrants than for US-born high earners
Most backdoor Roth guidance online is written for someone in their 40s or 50s who’s accumulated a decade-plus of pre-tax IRA rollovers, which is exactly what drives a high pro-rata percentage. A lot of H1B holders show up with no prior US retirement accounts at all: no old employer 401(k)s sitting around, no SEP-IRA from a previous business. If that’s your situation, your pro-rata percentage starts at or near zero by default, and the backdoor Roth genuinely can be close to tax-free with no extra rollover maneuvering. The trick is doing it before a job change leaves you with a rollover IRA, not after.
What happens if this is mismanaged
- Skipping Form 8606: without it, the IRS has no record that your contribution was already taxed, and you risk paying tax on the same money twice when you eventually withdraw it in retirement.
- Converting without checking for existing pre-tax IRA balances: the pro-rata rule applies whether or not you remember an old rollover IRA sitting at a previous employer’s brokerage. Forgetting a $50,000 balance doesn’t make it invisible to the IRS.
- Letting the contribution sit and grow before converting: earnings between the nondeductible contribution and the conversion become taxable, so converting within days rather than months avoids creating a taxable gain you didn’t need.
- Filing the wrong tax year on Form 8606: a contribution made in January for the prior tax year plus a conversion done that same month can span two different Form 8606 filings. Mixing these up is one of the most common backdoor Roth paperwork errors.
Use the calculator above to check your own eligibility and estimate your pro-rata tax hit before you convert. Already maxing this out and your 401(k) plan allows after-tax contributions? The Mega Backdoor Roth is the next lever worth looking at.
Frequently asked questions
Is the backdoor Roth IRA legal?
Yes. It's a two-step transaction — a nondeductible traditional IRA contribution followed by a Roth conversion — that the IRS has acknowledged and provided reporting forms for (Form 8606). There's no minimum required waiting period between the two steps under current law.
What is the pro-rata rule?
If you're holding any pre-tax money in a traditional, SEP, or SIMPLE IRA as of December 31 of the conversion year, the IRS treats every dollar you convert as a proportional mix of pre-tax and after-tax money. You can't just cherry-pick the new nondeductible contribution to convert tax-free.
Do I need to file anything with my taxes?
Yes, Form 8606, in both the year you make the nondeductible contribution and the year you convert. This is what tells the IRS how much of your IRA basis was already taxed, so you don't get taxed on it twice at withdrawal.
How much can I contribute to a backdoor Roth IRA in 2026?
The regular IRA contribution limit applies — $7,500 for 2026, traditional and Roth combined — since a backdoor Roth is really just a nondeductible traditional IRA contribution that gets converted, not a separate, bigger limit. Savers who want more room use a mega backdoor Roth through an employer 401(k) instead.
Written by WealthyDesis Team
Reviewed for accuracy against current IRS and USCIS guidance at time of publishing.
More in Retirement & Tax-Advantaged Accounts