For the better part of a decade, the single most valuable tax break available to American small business owners came with an expiration date stamped on it. The Qualified Business Income (QBI) deduction — the rule that lets eligible pass-through owners deduct up to 20% of their business income before they ever calculate tax — was scheduled to vanish at the end of 2025.
That cliff is gone. The 2025 tax law made the QBI deduction permanent, and even sweetened a few of its edges. For a profitable pass-through business, this can be the difference between a 37% top rate and an effective rate closer to 30%, year after year, with no sunset to plan around.
But "permanent" does not mean "automatic." The deduction is riddled with income thresholds, wage tests, and a special trap for service businesses — including most medical and dental practices. At Numbers Right, we see owners leave thousands of dollars on the table every spring simply because no one structured their income to capture it. Here is how Section 199A actually works in 2026, and how to make sure you get every dollar of it.
What the QBI Deduction Actually Is
Section 199A lets owners of pass-through businesses — sole proprietorships, partnerships, S-corporations, and many LLCs — deduct up to 20% of their qualified business income directly on their personal return. It is not a deduction against the business; it flows through to the owner’s Form 1040.
Qualified business income is, broadly, the net profit of your active U.S. business — not investment income, capital gains, S-corp wages you pay yourself, or guaranteed payments to partners. If your S-corp nets $200,000 in QBI, the deduction can shave $40,000 off your taxable income before the rate is even applied.
The QBI deduction rewards how your income is structured, not just how much you earn. Two owners with identical profit can pay wildly different tax depending on entity type, wages, and taxable income.
The Big 2026 Change: It Is Now Permanent
Under the original 2017 law, the QBI deduction was a temporary provision set to expire after 2025. The 2025 tax legislation removed that sunset entirely. The practical effect is enormous: owners can now build multi-year strategies — retirement plan design, entity elections, equipment timing — around a deduction they can count on, rather than racing to use it before it disappeared. The new law also widened the income "phase-in" ranges and added a small minimum deduction for owners with modest active business income.
Who Qualifies — and the Threshold That Changes Everything
The mechanics split sharply at an income line. For 2026, the taxable-income thresholds sit at approximately $200,000 for single filers and $400,000 for married couples filing jointly (these figures are indexed for inflation each year, so confirm the current number before relying on it).
Below the Threshold: The Simple Zone
If your total taxable income is under the threshold, the rule is wonderfully simple: you generally deduct 20% of your QBI, full stop. No wage tests, no asset tests, and — critically — no penalty for being a service business. The deduction is only as reliable as the profit it sits on, which is why disciplined bookkeeping matters.
Above the Threshold: Where It Gets Complicated
Once you cross the threshold, two additional tests apply, and your business type suddenly matters a great deal. For non-service businesses, the deduction is capped at the greater of these two amounts:
- 50% of the W-2 wages your business pays, or
- 25% of W-2 wages plus 2.5% of the unadjusted basis of your qualified depreciable property.
This is why a high-earning sole proprietor with no payroll can lose the deduction entirely above the threshold, while an otherwise identical S-corp that pays reasonable wages keeps it.
The SSTB Trap (Especially for Medical Practices)
Here is the rule that catches the most owners off guard. If your business is a Specified Service Trade or Business (SSTB) and your income climbs above the threshold, the QBI deduction phases out completely — no wages or assets can save it.
Businesses the IRS Treats as SSTBs
- Health — physicians, dentists, veterinarians, and most medical practices
- Law, accounting, and actuarial science
- Consulting, financial services, and investment management
- Performing arts and athletics
- Any business whose principal asset is the reputation or skill of its owners
For physicians and dental practice owners, this is the most important number in your tax plan: once household taxable income clears the joint threshold, the deduction shrinks and then disappears. That makes income management the whole game — the kind of planning our medical practice finance team builds into a year-round strategy rather than an April scramble.
Strategies to Maximize Your QBI Deduction
Because the deduction hinges on taxable income, wages, and entity structure, there are real, legal levers to pull. The right combination depends on your numbers, but these are the moves we use most often.
Common Levers That Preserve or Expand the Deduction
| Lever | How It Helps |
|---|---|
| Retirement contributions | A solo 401(k), SEP, or defined-benefit plan lowers taxable income, potentially dropping you back under the threshold. |
| S-corp wage tuning | For non-service firms above the threshold, paying enough W-2 wages can satisfy the 50% wage test and unlock the deduction. |
| Income timing | Deferring revenue or accelerating expenses across the year-end line can keep taxable income under the cliff. |
| Entity choice | Switching from sole proprietor to S-corp changes how wages and QBI interact — sometimes decisively. |
Notice the tension: paying yourself higher S-corp wages lowers your QBI, since wages are not QBI. Getting this right requires running the numbers both ways — the kind of modeling a CFO advisor or experienced preparer should do before you set your salary, not after.
Common Mistakes That Cost Owners Thousands
The deduction is forgiving below the threshold and unforgiving above it, and most errors cluster in three places.
Setting S-Corp Wages Without Modeling QBI
Owners often set "reasonable compensation" in isolation, then discover it shrank their QBI deduction or, conversely, failed the wage test. Salary and QBI must be solved together — ideally with payroll figures that are accurate to the dollar.
Ignoring Taxable Income Until April
The threshold is based on total taxable income, including a spouse’s wages and investment income — not just business profit. By the time you file, the year is over and the levers are gone. Mid-year projections catch this in time.
Treating Every Practice as Hopeless
Many physicians assume the SSTB rule disqualifies them and stop trying. But with retirement plan funding and smart income timing, a surprising number of practices can pull taxable income back under the threshold and reclaim a five-figure deduction through proper tax planning.
Don’t Leave 20% on the Table
The QBI deduction was always valuable, but its impermanence made long-term planning feel pointless. Now that it is a permanent fixture of the code, every profitable pass-through owner should have a deliberate, multi-year strategy to capture it. For high earners and medical practices in particular, the difference between planning and not is measured in tens of thousands of dollars.
Want to know exactly how much of the 20% deduction you are entitled to — and what to change before year-end to keep it? Schedule a free tax-strategy consultation and our team will model your QBI deduction from real numbers, tune your wages and retirement plan, and build a plan that captures every dollar the law now permanently allows.
