Wealth Building · 14 min read
The Backdoor Roth IRA
Congress closed the front door. Physicians use the back door. Completely legal. Worth $7,500 of tax-free growth per year — forever.
Reviewed by Jonathan Shafer, DO, July 2026. Disclosure: the reviewer is the founder and owner of Attending Financial LLC. This is education, not individualized financial advice.
Why physicians need the back door
For 2026, the ability to contribute directly to a 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 (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 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 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 is the trap.
Step 1 — Traditional IRA contribution
Contribute up to $7,500 for 2026 ($8,600 if 50+, with the $1,100 catch-up) to a traditional IRA. There is no income limit on the contribution itself. Mark it as non-deductible on Form 8606.
Step 2 — Immediate conversion
Convert the entire traditional IRA balance to a Roth IRA. Do this the same week to avoid taxable growth. Brokerage will issue Form 1099-R.
The pro-rata rule trap
If you have ANY pre-tax money in ANY traditional, SEP, or SIMPLE IRA on December 31, the conversion is taxed proportionally. A $60,000 rollover IRA + $7,500 backdoor contribution → only $833 of the conversion is tax-free; the rest is taxed at your marginal rate.
Mega backdoor Roth
If your 401k/403b allows after-tax contributions and in-service conversions, you can route a large after-tax sum into Roth: the 2026 total §415(c) limit is $72,000, minus your $24,500 employee deferral and any employer match — often $40,000+ of extra Roth room. Worth checking with HR; most plans do not allow it.
What the pro-rata rule actually costs
New attending in the 32% , with a $60,000 rollover IRA left over from a residency . 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 . Years earlier, leaving residency, a brokerage rep suggested they “roll over” an old into a . It felt tidy and responsible. It also planted a pre-tax IRA balance that now makes every backdoor conversion partly taxable under the — 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
Project the tax-free value of doing the every year for the rest of your career.
The pro-rata trap
A new attending wants to start the . They have a $60,000 rollover IRA from a residency they rolled over. They also have a 403b at their current job.
They want to contribute $7,500 to a and convert. Without action on the rollover IRA, only $833 of the conversion is tax-free.
Just do the backdoor — pay the small tax bill
On a $7,500 conversion with a $60,000 pre-tax IRA, approximately $6,667 of the conversion is taxable at marginal rate (32 percent = ~$2,100 tax bill). You also have a continuing problem for future years.
Roll the $60,000 rollover IRA into the current 403b first, then do the backdoor — the better choice
Correct sequence. 403b balances do not count toward the pro-rata calculation. After the roll-in, your traditional IRA balance is zero, and the backdoor conversion is fully tax-free. Confirm with HR that your 403b accepts roll-ins.
Skip the backdoor Roth this year
Possible but unnecessary. The roll-in solution is straightforward at most institutions. Skipping costs you the lifetime tax-free compound growth on this year contribution.
What triggers pro-rata
The single most important thing to check before doing a .
The pro-rata rule applies to your backdoor Roth conversion when:
Pro-rata looks across all your traditional/SEP/SIMPLE IRAs as one combined balance on December 31. 401k/403b balances do NOT count. Solo 401k balances do NOT count. Only the IRA family triggers pro-rata.
Your once-a-year backdoor Roth routine
Done in the right order, the whole thing is a 30-minute task each January. Here is the sequence.
- Confirm a $0 balance across all traditional, SEP, and SIMPLE IRAs. If anything pre-tax remains, roll it into your 401(k)/403(b) and let it settle before converting. — Before you start
- Contribute $7,500 ($8,600 if 50+) to a traditional IRA — ideally in January so the full year compounds tax-free. — January
- Convert the full balance to Roth within a few days, before it grows — any growth before conversion is taxable. — Same week
- File IRS Form 8606 for every year you do this. It records your basis and prevents double taxation. — At tax time
- Have your spouse do their own backdoor Roth too — each of you gets the full limit, $15,000–$17,200 combined. — Same window
- Ask HR whether your plan allows after-tax contributions plus in-service conversions (the mega backdoor). If yes, it unlocks far more Roth room. — Once
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.