Why a Doctor Who Owns Her Practice Can Get Under 30% While Her Salaried Colleague Pays 37% Plus Payroll Tax

Two internists. Same waiting room, same procedures, same billing codes. One draws a W-2 from the hospital system; her top wages hit the 37% federal bracket plus the 0.9% additional Medicare tax on high earners. The other owns her practice through an S corporation and can land her effective federal rate under 30%.

That gap is the way the code is built.

Deduction That Skipped Doctors on Purpose

When Congress wrote Section 199A in 2017, it handed pass-through business owners a 20% deduction on qualified business income (QBI). Pass-through means the business itself pays no federal income tax; profits flow to the owner’s Form 1040. An S corporation is the classic vehicle.

But the statute drew a line around what it calls specified service trades or businesses: medicine, law, accounting, consulting, financial services. Above the income phase-outs, the owner of one of these businesses gets no QBI deduction on the professional service itself. A cardiologist’s fee for reading an echo does not qualify.

A practice-owning doctor cannot simply deduct clinical income. The mechanism is subtler.

How the Owner Actually Gets Under 30%

She reclassifies everything sitting next to the clinical fees, which are stuck as service income.

• Ancillary services. In-office imaging, pathology lab, infusion suite, dispensed drugs, physical therapy. Structured separately, these are equipment and staff producing revenue independent of the doctor’s reputation or skill. The IRS treats them as non-service income, and the 20% QBI deduction applies.
• Procedural revenue. Depending on how the practice separates cognitive care from procedural income, the surgical or interventional line can reduce the service-income drag.
• Real estate rental. The doctor owns the medical office building through an LLC and leases it to her S corp. Rent is deductible to the practice and shows as qualifying rental income on her return, often with a QBI deduction and depreciation shielding much of it.

Add S corp mechanics. She pays herself a reasonable W-2 salary, subject to Social Security and Medicare payroll tax (15.3% combined up to the wage base, then 2.9% Medicare, then 0.9% additional Medicare surtax above $200,000 single). Everything else comes out as distributions, which escape payroll tax.

Stack those moves and the blended federal rate on total household income settles in the high twenties.

Why Her Salaried Colleague Is Stuck

The hospitalist across town collects a W-2. Every dollar is wages. There is no ancillary entity to spin off, no building to lease, no distribution channel to route around payroll tax. Her top dollars hit the 37% top bracket, and the wage runs through Social Security up to the annual wage base and Medicare tax on the whole thing, including the 0.9% add-on above the threshold.

She cannot reclassify wage income.

Economists Who Sized the Gap

The two-doctor comparison appeared on a recent Bloomberg Odd Lots episode, “There’s a Mind-Boggling Number of Rich People in America,” featuring authors of The Everywhere Millionaire, one a professor of economics at Princeton and one a professor of economics and finance at the University of Chicago Booth School of Business. Their point: US tax rules favor the business owner over the employee doing identical work, and medicine is the cleanest example.

What a Salaried Reader Can and Cannot Copy

You cannot turn a W-2 into an S corp. If your employer controls your schedule, patients, and billing, you are an employee.

What a high-earning employee can still do:

• Max the 401(k), including any mega-backdoor Roth.
• Fund an HSA if enrolled in a high-deductible plan; it is the only triple-tax-advantaged account in the code.
• Use a taxable brokerage with ETFs and tax-loss harvesting.
• If a legitimate side business exists, run it through its own entity to capture deductions and retirement-plan room.

Ownership is the dividing line. Everything downstream sits on that side.

Anyone weighing an entity restructuring, or a move from employment to ownership, should run this math with a CPA who has seen the service-business rules break both ways.

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