When Deferring Taxes Now Can Cost You Later
Most tax advice starts and ends with "defer as much as you can." That's often right — but not always. Here's when today's tax break becomes tomorrow's tax bill.
By Sanjay Pamurthy, CFP® & Devin Talbot, MBA | Artham Advisors | July 2026
Quick Answer: 401(k), IRA, cash balance plan, and real estate depreciation all work the same way — they lower your tax bill today by pushing income into the future. That's a bet, not a guarantee: it only pays off if your future tax rate is lower than today's. For high earners who save aggressively, that bet can go wrong in three ways — tax rates or brackets could rise, required withdrawals could push you into a higher bracket than you ever had while working, and tax-deferred accounts left to heirs skip the step-up in basis that taxable accounts get. The fix isn't to stop deferring — it's to diversify across tax-deferred, Roth, and taxable accounts so you're not betting everything on one outcome.
1.
Why Tax Deferral Is the Default Advice
If you've gotten financial advice as a physician, you've heard some version of "max out your 401(k)," "consider a cash balance plan," or "use accelerated depreciation on that rental property." All of these strategies share the same basic move: they push a tax bill from this year into some future year. A 401(k) or traditional IRA contribution shrinks this year's taxable income and grows tax-deferred until withdrawal. A cash balance plan does the same thing at a much larger scale for high-income practice owners. Accelerated depreciation on real estate front-loads deductions, shrinking taxable income today in exchange for a smaller deduction — and a taxable "recapture" — later.
All of this is genuinely useful — deferral can meaningfully lower your tax bill in your highest-earning years. But it's worth being clear-eyed about what deferral actually is: not a guaranteed tax reduction, but a bet.
2.
The Hidden Assumption: Deferral Is a Bet on Future Tax Rates
Every dollar you defer today is a dollar you'll eventually pay tax on later — at whatever your tax rate happens to be at that time. Deferral only "wins" if that future rate is lower than the rate you'd pay today. This is sometimes called tax bracket arbitrage: you're not avoiding tax, you're shifting it from a year you're confident is high-tax to a year you're hoping will be lower-tax.
For a resident earning $65,000 who expects to be an attending earning $350,000 within a few years, that bet is close to a sure thing — defer now, at a low rate, and it's very likely you'll never see that rate again. But for a high-earning, aggressive saver who spends modestly and accumulates a large balance over a long career, the bet gets much less certain. The larger a tax-deferred balance grows, the harder it becomes to guarantee a lower rate in retirement.
3.
Three Ways Deferral Can Backfire
Tax Rates and Brackets Can Change
Deferral assumes tomorrow's tax law looks something like today's. It might not. Tax rates and bracket thresholds are set by Congress and have shifted meaningfully over time, in both directions. A multi-decade deferral bet is, in part, a bet on future legislation entirely outside your control.
The Tax Torpedo and the Widow's Penalty
A large tax-deferred balance doesn't just get taxed on withdrawal — it can force a specific problem in retirement. Required minimum distributions (RMDs), which begin at age 73 or 75 depending on birth year, are mandatory whether or not you need the income, and a sufficiently large balance can push an otherwise modest retirement income into a much higher bracket than you were ever in while working. Layer on Social Security becoming taxable and Medicare's income-related surcharges (IRMAA), and the effective marginal rate on that last RMD dollar can run well above your stated tax bracket — a pattern often called the tax torpedo.
It gets worse for a surviving spouse. After one spouse dies, the survivor typically files as a single taxpayer the following year — and many single-filer bracket thresholds sit at roughly half of the married-filing-jointly thresholds. The same RMD that was comfortably taxed at a moderate rate as a couple can land in a meaningfully higher bracket for a widow or widower, with an account balance that hasn't changed at all. Financial professionals call this the widow's penalty.
Loss of the Step-Up in Basis for Heirs
Assets you hold in a taxable brokerage account get a valuable break at death: their cost basis "steps up" to fair market value, wiping out capital gains tax on decades of appreciation for whoever inherits them. Traditional IRAs, 401(k)s, and cash balance plan rollovers don't get this treatment. The IRS treats them as "income in respect of a decedent" — the tax bill you deferred simply transfers to your heirs, who owe ordinary income tax on every dollar withdrawn, generally within 10 years of your death under current law. A large pre-tax balance left to a high-earning adult child can end up taxed at a higher rate in their hands than it would have been in yours.
Title | Taxable Brokerage Account | Traditional IRA / 401(k) |
|---|---|---|
Withdrawal timeline | No forced timeline | Generally within 10 years (SECURE Act) |
Tax owed by heir | Little to none on gains through your death | Ordinary income tax on the full pre-tax balance |
Basis at your death | Steps up to fair market value | No step-up — retains your original basis |
4.
Building Tax Diversification Instead of Pure Deferral
None of this means deferral is a mistake — for most high earners in peak earning years, meaningful deferral is still the right move. The fix isn't to stop deferring, it's to avoid betting your entire tax outcome on a single guess about the future.
HOLD A MIX OF ACCOUNT TYPES: Contribute to traditional accounts for the immediate deduction, but also fund Roth accounts — Roth 401(k), backdoor Roth IRA, or mega backdoor Roth where available — so a portion of your savings grows completely tax-free with no RMDs.
CONVERT IN LOW-INCOME YEARS: A gap between retirement and RMDs, a slow year in practice, or a sabbatical can be a good window to convert traditional balances to Roth at a lower rate — a strategy often called "filling the bracket."
PLAN CASH BALANCE PLAN PAYOUTS AHEAD OF TIME: A cash balance plan rollover creates a large pre-tax IRA balance overnight. Decide in advance how you'll manage that balance — including its effect on backdoor Roth contributions and future RMDs — rather than reacting after the fact.
REMEMBER DEPRECIATION ISN'T FREE, EITHER: Depreciation recapture on real estate is taxed at sale, generally at a rate up to 25% federally. It's usually still a favorable trade, but it's a partial offset, not a free deduction.
Bottom line: Deferral is a valuable tool, not a guaranteed win. Use it deliberately in your highest-earning years, but build tax diversification alongside it so a large pre-tax balance doesn't become a bigger problem in retirement — or a bigger bill for your heirs.
→ Related:
Not sure if you're over-deferring?
Most physicians have never modeled what their tax-deferred balances will actually look like at RMD age — or what they'll cost their heirs. We'll help you find the right balance between tax-deferred, Roth, and taxable savings for your specific situation, and build a plan for Roth conversions and cash balance payouts before you need one. No products, no commissions. We are fee-only and fiduciary; we earn nothing from any product or referral tied to your tax planning.
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Frequently Asked Questions
Not always. Deferral lowers your tax bill today, but it only produces a real long-term benefit if your tax rate when you withdraw the money is lower than your rate today. For high earners who save aggressively over long careers, that assumption doesn't always hold — which is why pairing deferral with Roth and taxable accounts is usually a better approach than deferring as much as possible.
The tax torpedo describes how required minimum distributions from a large tax-deferred account, combined with the taxation of Social Security benefits and Medicare's IRMAA surcharges, can push the effective marginal tax rate on your last dollar of income well above your stated tax bracket in retirement.
It's the higher tax bill a surviving spouse can face after filing as a single taxpayer instead of married filing jointly. Because many single-filer tax brackets are roughly half as wide as married-filing-jointly brackets, the same retirement account balance and required distributions can push a widow or widower into a meaningfully higher bracket than the couple faced together.
No. Traditional IRAs, 401(k)s, and similar pre-tax accounts are treated as "income in respect of a decedent" and do not receive a step-up in basis at death. Heirs owe ordinary income tax on the full balance as they withdraw it, generally within 10 years under current law. Taxable brokerage accounts, by contrast, do get a step-up, which can eliminate capital gains tax on appreciation that occurred during your lifetime.
Usually not. For most physicians in peak earning years, tax-deferred contributions still provide real value. The goal isn't to stop deferring — it's to balance deferral with Roth and taxable savings so you aren't relying entirely on a bet that your future tax rate will be lower.
Hold a mix of traditional (tax-deferred), Roth, and taxable accounts rather than concentrating savings in one type. Consider Roth conversions in lower-income years, contribute to Roth 401(k) or backdoor Roth accounts alongside traditional contributions, and plan ahead for how large pre-tax balances — like a cash balance plan rollover — will be distributed or converted over time.
Further Reading & Sources
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Kitces.com: Finding Your Tax Equilibrium Rate When Liquidating Retirement Accounts
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Kitces.com: The IRD Deduction Inherited IRA Beneficiaries Often Miss
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White Coat Investor: Roth vs. Tax-Deferred — The Critical Concept of Filling the Brackets
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White Coat Investor: Tax Diversification to Reduce Taxes
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White Coat Investor: Step Up in Basis — What You Need to Know
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Physician on FIRE: The Cash Balance Plan
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Bogleheads Wiki: Income in Respect of a Decedent
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Bogleheads Wiki: Traditional versus Roth
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Disclosure: This article is for educational purposes only and does not constitute personalized financial, legal, or tax advice. Tax rates, thresholds, and rules referenced here reflect 2026 figures and are subject to change; consult a qualified CPA or tax attorney about your specific situation. Artham Advisors LLC is a registered investment adviser (SEC disclosure). Registration does not imply a certain level of skill or training. Past performance is not indicative of future results. © 2026 Artham Advisors.