If you make too much to contribute to a Roth IRA directly, you've probably heard about the backdoor Roth — the workaround where you fund a traditional IRA and convert it.
It's legal, it's popular, and for years it's been the retirement move that quietly worked in the background for higher earners.
Here's the catch that's tripping people up this tax season: the conversion step creates a taxable event, and the IRS wants its cut reported on the right form, in the right year.
Miss it, and you can end up owing taxes on money you thought was already handled — or worse, paying penalties on a form you filed wrong.
You contribute to a traditional IRA — up to $7,000 for 2024, or $8,000 if you're 50 or older.
Because your income is above the deduction limit, that contribution isn't tax-deductible, which is exactly what you want.
Since you already paid tax on it, the conversion is usually tax-free.
The problem is what's called the pro-rata rule.
If you have any other traditional IRA money sitting around — an old 401(k) rollover, a SEP IRA, a SIMPLE IRA — the IRS doesn't let you convert just the after-tax dollars.
It looks at all your IRA balances together and taxes the conversion proportionally.
Someone with $50,000 in a rollover IRA and a $7,000 backdoor contribution could suddenly owe tax on most of that conversion.
The fix most CPAs recommend is rolling existing pre-tax IRA money into a workplace 401(k) before December 31 of the year you do the conversion.
That clears the deck so the pro-rata rule doesn't apply.
But many people learn this too late, after the calendar has already flipped.
Your IRA custodian issues Form 1099-R for the conversion, and you have to file Form 8606 to track the after-tax basis.
Skip the 8606 and the IRS has no way to know you already paid tax on that money.
The result: a letter, a bill, and an afternoon on hold with the agency.
Conversions are reported for the year they happen, not the year you contribute.
So a contribution made in early 2025 for tax year 2024, then converted in 2025, shows up on 2025's taxes.
Mixing those up is one of the most common errors tax preparers see.
The move is still worth it for many people.
Tax-free growth, no required minimum distributions, and a tax-free bucket in retirement are hard to beat.
But it isn't a set-it-and-forget-it strategy.
It needs a check on your other IRA balances, a look at your marginal tax bracket, and a conversation with a tax pro before you click convert.
If you've done a backdoor Roth in the past and never filed Form 8606, it's worth going back and checking.
The IRS allows you to file missing forms without a penalty in many cases, and cleaning it up now is far cheaper than getting a notice later.
The bottom line: the backdoor Roth is a legitimate tool, but it rewards people who read the fine print and punishes those who don't.
Final Thoughts
Treat it like the tax maneuver it is — because that's exactly what it is.