The §199A wage trap, and why most S-corp calculators are wrong

Section 199A gives owners of pass-through businesses a deduction of up to 20% of qualified business income. It was made permanent by the One Big Beautiful Bill Act in July 2025, and for 2026 it interacts with the S-corp decision in a way that trips up almost every simple calculator.

The naive S-corp calculation goes like this:

• Profit is $200,000.
• Pay yourself $80,000 in salary; take $120,000 in distributions.
• You avoid 15.3% self-employment tax on $120,000.
• That is roughly $18,000 saved. Elect immediately.

The arithmetic is right and the answer is wrong, because moving $120,000 out of self-employment income also moved it out of the §199A base — and then, depending on your income, may have rescued the deduction from disappearing altogether.

Force one: wages are not qualified business income

QBI is the net income of the trade or business. W-2 wages paid to you as an employee are explicitly excluded. So every dollar you shift from distribution to salary is a dollar removed from the QBI base, and the deduction is 20% of that base.

The cost is about 20 cents of deduction per dollar of salary, worth your marginal rate. In the 24% bracket that is roughly 4.8 cents of real tax per dollar shifted. Against the 15.3% payroll tax you are avoiding, electing still wins — but by noticeably less than the naive number suggested.

Force two: above the threshold, wages are what save the deduction

For 2026 the §199A threshold is $201,750 of taxable income for single filers and $403,500 for joint filers. Below it, you take 20% of QBI and the analysis stops. Above it, a limitation phases in over the next $75,000 (single) or $150,000 (joint) — widened from $50,000 and $100,000 by the OBBBA.

Once fully phased in, the deduction is capped at the greater of:

• 50% of the W-2 wages paid by the business, or
• 25% of W-2 wages plus 2.5% of the unadjusted basis of qualified property.

Read that again with a sole proprietor in mind. A sole proprietor pays no W-2 wages. They have no meaningful qualified property either, if the business is a laptop and a phone. So above the phase-in range, their cap is essentially zero — and the deduction they thought was worth tens of thousands collapses to the OBBBA minimum of $400.

The arithmetic, at $400,000 of profit

Single filer, no other income, fully past the phase-in range:

The sole proprietor has more QBI and gets almost none of the deduction. The S corporation has less QBI and keeps all of it, because it paid wages. At a 32% marginal rate that difference alone is worth roughly $14,000 — before counting a single dollar of payroll tax saved.

Where the optimum actually sits

Two opposing forces mean there is a genuine interior optimum rather than a corner solution. Setting 20% of QBI equal to 50% of wages and solving gives a tax-optimal salary of roughly 28% of profit.

Which is a slightly awkward result, because 28% is below what most practitioners would defend as reasonable compensation. In practice, then, the legal floor binds before the arithmetic one does — and the honest conclusion is that at high profit the two constraints nearly coincide, so a salary around 30% to 40% of profit is close to optimal and defensible at the same time. How to build that number properly is here.

If you are a specified service business, none of this may apply

For an SSTB — consulting, law, health, accounting, financial services, athletics, performing arts, or any business whose principal asset is the reputation or skill of its owners — the deduction phases out completely across the same range. Past $276,750 of taxable income (single) or $553,500 (joint), the deduction is gone regardless of how much you pay in wages.

That simplifies the S-corp decision considerably: with no deduction to protect, the analysis reverts to payroll tax against compliance cost. It also makes anything that lowers taxable income unusually valuable while you are inside the phase-out, because each dollar of reduction restores deduction as well as reducing tax. A solo 401(k) contribution in that band can carry an effective rate well above your nominal bracket.