If your income is too high to contribute directly to a Roth IRA, the Backdoor Roth is one of the cleanest ways to still get money into tax-free growth.
But it’s also one of those strategies that’s simple in theory… and easy to mess up in practice.
Here are the two biggest mistakes we see (and how to avoid them).
1) Forgetting the “pro-rata rule”
A Backdoor Roth works best when your Traditional IRA balance is $0.
Why? Because the IRS doesn’t let you convert “just the after-tax dollars.” Instead, they look at all of your pre-tax IRA money combined (Traditional IRA, Rollover IRA, SEP IRA, SIMPLE IRA) and apply a percentage rule.
So if you contribute $7,000 after-tax and convert it… but you also have $93,000 sitting in an old rollover IRA, the IRS may treat most of your conversion as taxable.
Fix: If you have pre-tax IRA money, a common workaround is to roll it into your 401(k) (if your plan allows it) before doing the Backdoor Roth.
2) Contributing… but skipping Form 8606
Backdoor Roth IRAs depend on properly tracking “after-tax basis.” That happens on IRS Form 8606.
Miss this and you can end up paying tax twice:
once when you earn the money… and again when you convert it.
Fix: Make sure Form 8606 is filed for the year of the contribution/conversion. (Even if you use a CPA, don’t assume it’s automatic—ask explicitly.)
The “clean” Backdoor Roth checklist
If you want the smoothest execution:
✅ Confirm you don’t have other pre-tax IRA balances (or roll them into a 401(k))
✅ Make a non-deductible Traditional IRA contribution
✅ Convert to Roth IRA shortly after
✅ File Form 8606 correctly
Why it’s worth doing
A Backdoor Roth isn’t just a tax trick. It’s a way to build a tax-free bucket that can give you flexibility later, especially when you’re managing future tax brackets, early retirement years, or big life transitions.
If you want, we can quickly sanity-check whether you’re a good candidate and help you avoid the pro-rata trap before it becomes a surprise on your tax return.