If you make too much money to contribute to a Roth IRA, you've probably heard the workaround: fund a traditional IRA, convert it, and pay tax on the gains.
It's called the backdoor Roth, and for years it ran quietly in the background for high earners who didn't qualify for the front door.
Now a mix of updated IRS guidance and fresh scrutiny on the pro-rata rule is tripping up people who thought they had it figured out.
Here's the catch that keeps biting savers.
The pro-rata rule looks at *all* your traditional IRA money on December 31 of the conversion year, not just the account you're converting.
If you have a rolled-over 401(k) or an old deductible IRA sitting around, the IRS treats your after-tax contributions as a slice of one big pie.
That means a chunk of your "tax-free" conversion suddenly becomes taxable.
Say you contribute $7,000 after-tax and convert it, but you also have $63,000 in a rollover IRA.
Under the pro-rata formula, roughly 90% of your conversion is taxable.
People expect a clean $7,000 conversion and get a surprise tax bill in the thousands.
The fix is often to move that pre-tax money into a workplace 401(k) before December 31, which is allowed at many employers but not all.
The contribution limits themselves shift with inflation.
For 2025, the IRA limit is $7,000, with a $1,000 catch-up if you're 50 or older.
Roth income phase-outs also adjust each year, so the exact salary where you lose direct Roth eligibility creeps upward.
If you're near the line, checking the current numbers matters more than relying on what you remembered two years ago.
Conversions are reported on Form 8606, and that form has to be filed with the return for the year of the conversion—even if no tax is owed.
Plenty of people skip it because their tax software didn't flag it, then face a letter from the IRS months later.
If you do a conversion in 2025, the taxable amount lands on your 2025 return, filed in early 2026.
There's also the five-year rule to keep straight.
Each conversion starts its own five-year clock for penalty-free access to the converted amount if you're under 59½.
It's separate from the five-year rule on Roth earnings.
Converting every January, as some people do, builds a stack of overlapping clocks that are easy to lose track of.
Congress never banned it, and the IRS has acknowledged the two-step maneuver in its own guidance.
But "legal" and "simple" are different things.
The people who get burned are usually the ones who converted without checking their other IRA balances first.
The practical move: before you convert, add up every traditional, SEP, and SIMPLE IRA you own.
If the pre-tax total is large, talk to your plan administrator about rolling it into a 401(k) first.
If it's small or zero, the backdoor stays clean.
Either way, run the numbers before December, not in April when the 8606 is already late. **Our take:** The backdoor Roth is still one of the better deals available to high earners, but it rewards people who read the fine print and punishes people who assume.
Final Thoughts
Spend an hour with your account balances before you convert—that hour is cheaper than the tax bill.