The Backdoor Roth IRA

Why physicians need the back door

For 2026, the ability to contribute directly to a Roth IRA phases out between $153,000 and $168,000 of income for single filers, and between $242,000 and $252,000 for married-filing-jointly. Most attending physicians clear both ceilings and are locked out of the front door entirely. The IRS left the back door open on purpose. You contribute to a traditional IRA (no income limit on the contribution) and then convert it to a Roth (no income limit on conversions). The end state is identical to a direct Roth contribution: $7,500 of after-tax money compounding tax-free, withdrawable tax-free in retirement. Congress explicitly blessed this in the 2017 tax law. Every high-earning physician without a pre-tax IRA balance should be doing it — and the one trap that ruins it is a rule you already half-know from the pro-rata calculations in your training.

The pro-rata rule (IRC §408(d)(2))

When you convert, the IRS treats every traditional, SEP, and SIMPLE IRA you own as one combined pool and taxes the conversion in proportion to how much of that pool is pre-tax money. It does not let you cherry-pick the after-tax dollars you just contributed.

The mechanics of the backdoor Roth are trivial. Exactly one rule determines whether your conversion is tax-free or a surprise tax bill.

Why it matters: Workplace plans — 401(k), 403(b), 457(b), solo 401(k) — are NOT in the pool, so they never trigger pro-rata. Only the IRA family does. That single distinction is the whole game: a clean $0 IRA balance on December 31 means a fully tax-free conversion; a leftover rollover IRA from residency means most of your conversion gets taxed.

The four-step picture

Tap each card. The steps are simple. The pro-rata rule is the trap.

What the pro-rata rule actually costs

New attending in the 32% marginal bracket, with a $60,000 rollover IRA left over from a residency 403(b). They contribute $7,500 non-deductible and convert it.

Bottom line: The same $7,500 conversion that is completely free for a colleague with no IRA balance costs this physician about $2,133 in tax — and strands $6,667 of basis to untangle next year. The fix is never to skip the backdoor; it is to empty the IRA pool first by rolling the $60,000 into a 403(b), where it does not count toward pro-rata.

The residency rollover IRA that quietly blocks the door

Here is how most physicians botch their first backdoor Roth. Years earlier, leaving residency, a brokerage rep suggested they “roll over” an old 403(b) into a traditional IRA. It felt tidy and responsible. It also planted a pre-tax IRA balance that now makes every backdoor conversion partly taxable under the pro-rata rule — quietly, every single year they leave it sitting there.

How to avoid it: Before your first backdoor Roth, check every traditional, SEP, and SIMPLE IRA you own. If any holds pre-tax money, roll it INTO your current employer's 401(k)/403(b) — or a solo 401(k) if you have 1099 income — because workplace plans are exempt from pro-rata. Confirm the plan accepts incoming roll-ins, complete the roll-in, and verify a $0 IRA balance before December 31 of the conversion year. And never roll a workplace plan the other direction, into an IRA, if you intend to keep doing backdoor Roths.

Your backdoor Roth lifetime value

The pro-rata trap

What triggers pro-rata

Step-by-step this year

• Confirm no pre-tax traditional/SEP/SIMPLE IRA balance on December 31. If there is, roll it into your 401k/403b first.
• Contribute $7,500 ($8,600 if 50+) to a traditional IRA in January for cleanest timing.
• Convert to Roth within days. Do not let the money grow in the traditional IRA — growth is taxable.
• File Form 8606 every year you do the backdoor. The form establishes basis and protects you from double taxation.
• Married couples: each spouse can do their own backdoor Roth — $15,000-$17,200 combined annually.

Do this next: Open your brokerage app. Check your traditional/SEP/SIMPLE IRA balances. If clean, start the backdoor Roth now. If not, contact HR about a 403b roll-in.