Roth Conversion Strategy for Physicians: When, How Much, and Why It Matters

Most physicians reach retirement with $1M–$4M+ in traditional 401(k), 403(b), and IRA accounts — and almost nothing in Roth. That ratio wasn't an accident: pre-tax contributions made sense during peak earning years at 37% marginal rates. But it creates a compounding problem in retirement. The IRS requires minimum distributions starting at age 73 (born 1951–1959) or age 75 (born 1960+) under SECURE 2.0. A $3M pre-tax balance at age 73 generates roughly $115,000/year in mandatory taxable distributions — income you can't control, can't defer, and can't shelter. At that point, it's too late to run the math differently. Roth conversions — deliberately paying taxes now to convert pre-tax accounts to Roth — are how physicians get ahead of that problem. The strategy only works if you identify the low-rate windows in your career and act during them, not after.

Why Roth Conversions Are Especially Valuable for Physicians

The physician financial arc makes Roth conversions more valuable than they are for most professions:

• Delayed start, compressed accumulation. A 28-year-old intern who finishes fellowship at 34 has six fewer years to build Roth assets than a peer who started working at 22. Starting conversions early closes that gap.
• Maximized pre-tax contributions during peak years. Physicians who max a 403(b)/401(k) + 457(b) + cash balance plan can shelter $150,000+/year from income taxes. Efficient during working years, but it means a massive pre-tax balance generating large mandatory RMDs later.
• IRMAA exposure. Medicare surcharges begin at $109,000 MAGI for single filers and $218,000 for married couples filing jointly (2026). A physician couple with $3M in pre-tax accounts, $80K in Social Security, and $60K in investment income will likely face Tier 3–Tier 4 IRMAA ($527–$649/month per person) throughout retirement — over $12,000/year in Medicare surcharges alone — unless they systematically reduce their pre-tax balance before RMDs begin. See IRMAA and Medicare Planning for Physicians for the full bracket breakdown.
• Estate efficiency. Inherited traditional IRAs are now subject to the 10-year distribution rule under SECURE 2.0. Your heirs — who may be in high income-earning years — must take all distributions within 10 years and pay ordinary income tax on every dollar. Inherited Roth IRAs follow the same 10-year rule but with no income tax. Converting during low-rate windows shifts the tax burden from your heirs' high brackets to your lower current rate.

The Three Physician Conversion Windows

Window 1: Residency and Fellowship (Ages 27–34)

Residents and fellows typically earn $60,000–$85,000/year. After the 2026 standard deduction of $32,200 (married filing jointly), a household taxable income of $28,000–$53,000 falls in the 12% bracket — the lowest most physicians will ever see as adults.¹

Two Roth moves matter here:

• Direct Roth IRA contributions: At resident income levels, single filers are below the $153,000 phase-out and married filers are below the $242,000 MFJ phase-out, so direct Roth IRA contributions are available — $7,500 base limit for 2026, or $8,600 at age 50+.² Use them. This may be the last time in your career you're under the phase-out threshold.
• Convert any existing pre-tax IRA balance: If you rolled over a 403(b) or 401(k) from a pre-residency job into a traditional IRA, convert it during residency. Converting $40,000 of pre-tax IRA assets at 12% costs $4,800 in tax. That same $40,000 left to grow to $300,000 by retirement would be fully taxed at 32–37% when distributed — a $96,000–$111,000 tax bill. The 12% window is brief. Use it.

Window 2: Career Transition or Income-Gap Year

Physicians experience income dips more often than most: the gap between residency end and first attending check, a year of locum work during burnout, going part-time for family reasons, leaving a health system without immediately starting a new position. These are prime conversion windows. A physician whose income drops from $400,000 to $150,000 in a transition year may find their marginal rate is 22–24% rather than 35–37%. Every dollar converted in that year converts at a dramatically lower rate.

If you're considering a career transition, look at the tax year's projected income before it closes. A $50,000 Roth conversion in a 22% year costs $11,000. In a 37% year, it costs $18,500. The difference is real.

Window 3: Pre-Medicare Early Retirement (Ages 62–72)

This is the highest-leverage window for most physicians. After your last W-2 paycheck clears but before RMDs begin and before you claim Social Security, your taxable income may be lower than at any point since residency. Investment income, some rental income, and possibly modest part-time locum income — but no full attending salary, no 457(b) distributions forcing income recognition. A physician couple retiring at 62 with $80,000/year in portfolio distributions has taxable income of roughly $47,800 after the $32,200 MFJ standard deduction. That's in the 12% bracket — the same rate they saw during residency.

Systematic conversions during this window can permanently reduce the pre-tax balance that will generate forced RMDs at 73 or 75. The math compounds in multiple directions: less pre-tax → smaller RMDs → lower MAGI → lower IRMAA tier → more Roth → MAGI-neutral income in high-surcharge years → better estate outcomes for heirs.

How Much to Convert: Bracket Targeting

The core technique is filling a tax bracket — converting only as much as can be absorbed at a target rate, then stopping before the next bracket cliff. The 2026 federal income tax brackets for single filers (IRS Rev. Proc. 2025-32):¹

Source: IRS Rev. Proc. 2025-32. Standard deduction 2026: $16,100 single / $32,200 MFJ. MFJ brackets are approximate based on IRS inflation-adjusted values. Verify exact thresholds at IRS.gov before filing.

A physician couple (MFJ) in early retirement with $70,000 in dividend and interest income has taxable income of ~$37,800 after the standard deduction. They're in the 12% bracket. They can convert up to ~$61,800 more in Roth conversions before hitting the 22% bracket, or up to ~$174,500 more before hitting the 24% bracket — each dollar at their chosen rate.

The IRMAA Cliff: Stop Before You Jump

Roth conversions count as MAGI for IRMAA purposes in the year they are recognized. Your 2026 Medicare premiums are based on 2024 MAGI — so conversions you make in 2026 will affect your 2028 Medicare premiums. The key thresholds for 2026 IRMAA surcharges (from your 2024 MAGI):

• Tier 1 starts at $109,000 single / $218,000 MFJ — adds $1,148/year per person
• Tier 2 starts at $137,000 single / $274,000 MFJ — adds $2,885/year per person
• Tier 3 starts at $171,000 single / $342,000 MFJ — adds $3,780/year per person
• Tier 4 starts at $205,000 single / $410,000 MFJ — adds $5,555/year per person

The practical implication: if a $20,000 Roth conversion pushes you from Tier 1 to Tier 2, you pay an extra $2,885 in IRMAA surcharges for that Medicare year — plus the tax on the conversion. In some cases that math still works. In other cases, you're better off stopping the conversion $1 under the cliff. Run the numbers before December 31 of each year, adjusting the conversion amount to land just below the next IRMAA threshold.

Physicians younger than 63 who are pre-Medicare don't need to worry about IRMAA yet — convert aggressively while you can. The IRMAA calculation begins mattering once you're within 2–3 years of Medicare enrollment. See the full IRMAA Medicare Planning Guide for a year-by-year coordination framework.

The Pro-Rata Rule: A Trap for Residents

Residents who do backdoor Roth IRA contributions (nondeductible traditional IRA → convert to Roth) often have pre-existing traditional IRA balances from an old rollover. This triggers the pro-rata rule: the IRS treats all your traditional IRA assets as a pool, and each conversion is taxed proportionally. A $7,500 nondeductible contribution into a traditional IRA that also holds $67,500 of pre-tax rollover assets means 90% of the conversion is taxable — even if you only intended to convert the new after-tax contribution. The fix is to roll the pre-tax IRA balance into your employer's 401(k) or 403(b) before doing the backdoor Roth, if the plan accepts incoming rollovers. See Backdoor Roth IRA for Physicians for step-by-step mechanics and the reverse rollover solution.

Roth 401(k) as a Parallel Strategy

You don't have to convert existing balances to get Roth exposure. If your employer's plan offers a Roth 401(k) or Roth 403(b) option, directing some or all of your $24,500 deferral (2026 limit) there builds Roth assets without a current conversion — and since 2024, Roth 401(k) accounts no longer have lifetime RMDs (SECURE 2.0 §325).³ The tradeoff: you're making the contribution at your current marginal rate (which may be 37% during peak attending years) rather than deferring and converting later at a lower rate. Roth 401(k) contributions make most sense for residents and fellows who expect their future rate to be higher, or for practice owners who want Roth diversification without managing conversion logistics.

Common Physician Roth Conversion Mistakes

1. Converting nothing during residency. The 12% bracket disappears the moment the first attending paycheck arrives. Physicians who don't convert existing pre-tax balances during training leave a permanent low-rate window unused.
2. Waiting until after RMDs begin. Roth conversions after age 73 (or 75) cannot count toward the RMD amount — you must take the RMD first, then decide whether to convert additional amounts. At that point, total income (RMD + SS + investment income + conversion) easily pushes into IRMAA Tier 3 or Tier 4. Converting when income is already high partially defeats the purpose.
3. Converting in a 457(b) distribution year. Non-governmental 457(b) plans must be distributed within two years of separation. Physicians who add a Roth conversion to a year they're also receiving $300,000–$400,000 in 457(b) proceeds are converting at 37% — often the worst possible time. Coordinate conversion years around known income spikes.
4. Ignoring state income tax. A physician in California (13.3% top state rate) pays a combined federal + state rate of up to 50.3% at peak income — but may pay 0% state on conversions if they retire to Florida, Nevada, Texas, or another no-income-tax state. If you plan to relocate at retirement, factor state rates into the pre-retirement conversion decision. Converting in a state with high income tax for 30 years before moving is suboptimal if conversions could be executed post-move at zero state tax.
5. Over-converting past the IRMAA cliff. Jumping from Tier 1 to Tier 2 IRMAA for a conversion you could have spread over two years costs ~$2,885/year in extra Medicare surcharges for as long as your income stays in that tier. Model the cliff before executing.
6. Using Roth funds to pay the conversion tax. The conversion tax should be paid from outside savings, not from the Roth account being built. Paying the tax from a non-retirement account preserves the full converted amount inside the Roth wrapper. Using Roth funds effectively reduces the amount converted and loses the tax-free compounding on those withdrawn dollars.

Decision Framework: Should You Convert This Year?