What Are Personal Services Under Federal Tax Law?

Under federal tax law, personal services are professional activities where the value delivered comes from an individual’s training, skill, and judgment rather than from a product, inventory, or capital equipment. The Internal Revenue Code singles out eight fields as personal services and applies distinct rules to businesses that operate in them, covering the tax year they must use, the accounting method they can elect, how losses are treated, how much income they can retain, and when the IRS can reallocate income back to the owner. Getting the classification wrong can trigger income reallocation, a forced change in accounting method, and unexpected tax bills.

The Definition That Drives the Rules

The core idea is straightforward. If a business earns money primarily through human effort and specialized knowledge, it falls into the personal services category. A surgeon’s value comes from years of training, not from the operating table. A consultant’s deliverable is judgment and advice, not a manufactured item.

Federal law captures this by asking two questions: is the performance of services the corporation’s principal activity, and are those services substantially performed by the people who own the business? When the answer to both is yes, the entity is treated as a personal service corporation with obligations that don’t apply to ordinary C corporations.¹

Congress built these rules because high-earning professionals could otherwise park income inside a corporate shell to access lower brackets or defer compensation indefinitely. The personal services classification closes those doors.

The Eight Fields

Internal Revenue Code Section 448(d)(2) lists the professional fields that qualify as personal services:²

Health, including medical practices, dental offices, physical therapy clinics, and veterinary services³
Law, including firms and solo practices
Engineering, across civil, mechanical, electrical, and other specialties
Architecture, including design and planning firms
Accounting, including CPA firms and bookkeeping practices
Actuarial science, covering firms providing risk assessment and statistical analysis
Performing arts, meaning actors, musicians, and other performers whose income depends on personal talent
Consulting, where the deliverable is professional advice rather than a product

These fields share a common thread: the practitioner’s skill is what the client is buying. The IRS has confirmed that health extends to veterinary services, so a veterinary practice organized as a C corporation faces the same classification rules as a medical clinic.³

One boundary is worth flagging. The consulting category covers businesses whose primary service is advice. A firm that earns most of its revenue from selling products and offers consulting as an add-on likely falls outside the classification, because the IRS looks at the corporation’s principal activity rather than its marketing.

When a Corporation Is Treated as a PSC

Operating in one of the eight fields isn’t enough on its own. The IRS applies a three-part test during a testing period, generally the prior tax year.³

The Function Test

The corporation’s principal activity must be performing personal services in one of the eight fields. Under Treasury regulations, 95 percent or more of employee time must be devoted to qualifying services. A medical practice where nearly all staff hours go to patient care passes easily. A firm that calls itself a consulting company but earns 60 percent of its revenue from equipment sales would not.

The Performance Test

The employee-owners must substantially perform the services themselves. The IRS considers this met if more than 20 percent of the corporation’s compensation cost for personal services goes to services performed by employee-owners during the testing period.³ This prevents owners from hiring staff to do all the work while collecting corporate-level tax benefits.

The Ownership Test

Employee-owners must hold more than 10 percent of the fair market value of the corporation’s outstanding stock on the last day of the testing period.¹ An employee-owner is someone who both works for the corporation and owns stock. Constructive ownership rules apply, so stock held by family members or related entities can count toward the threshold.

For the stricter “qualified personal service corporation” definition used in accounting method rules under Section 448, substantially all of the corporation’s stock must be held by current employees performing services, retired employees, their estates, or heirs, with the estate and heir window limited to two years after the employee’s death.² Losing this status, for instance when an outside investor acquires a large stake, can force an immediate change in accounting method.

How PSCs Are Taxed

All C corporations, including personal service corporations, currently pay a flat 21 percent federal income tax rate.⁴ The rate itself is no longer the pressure point it once was, but several structural constraints still apply only to PSCs.

Mandatory Calendar Year

A PSC must use the calendar year as its tax year unless it can prove a legitimate business purpose for a different period.⁵ The desire to defer income to shareholders does not count. This rule shuts down the older strategy of setting a fiscal year-end that creates a timing gap between when the corporation deducts compensation and when the employee-owner reports the income.

A PSC can elect a non-calendar fiscal year under Section 444, but the election comes with strings. The corporation must make required payments to the IRS that approximate the tax benefit of the deferral, and if it fails to distribute enough compensation to employee-owners during the deferral period, its deductions for those payments get capped.⁶

Cash Method of Accounting

Most C corporations must use the accrual method, which recognizes income when earned and expenses when incurred. Qualified personal service corporations get an exception. They can use the cash method regardless of their revenue size.² Cash accounting is simpler and can offer timing benefits, since the corporation doesn’t recognize income until it actually receives payment. For a law firm or medical practice with unpredictable collection cycles, that matters.

When the IRS Can Reallocate Your Income

Section 269A gives the IRS a powerful tool. If substantially all of a PSC’s services are performed for a single client and the principal purpose of the corporate structure is avoiding or reducing individual income tax, the IRS can reallocate income, deductions, credits, and other tax items between the corporation and its employee-owners.¹

This is where many one-person professional corporations run into trouble. A software consultant who incorporates, works exclusively for one company, and routes all income through the corporation to access corporate deductions and fringe benefits is exactly the scenario Section 269A targets. The IRS doesn’t need to prove fraud. It only needs to show that the structure’s principal purpose is tax avoidance and that the PSC is essentially a single-client operation. When the IRS uses this power, it reclassifies corporate income as personal income on the employee-owner’s individual return, erasing whatever tax benefit the structure produced.

Passive Losses Get Trapped

Passive activity loss rules hit personal service corporations harder than other closely held businesses. Under Section 469, a PSC generally cannot use losses from passive activities like rental real estate or limited partnership investments to offset its active professional income.⁷

Other closely held C corporations get a partial break. They can offset passive losses against net active income even if they can’t offset them against portfolio income. PSCs are specifically excluded from that exception.⁷ A medical practice that buys a rental property through the corporation and takes a loss cannot use it to reduce taxable professional income. The loss sits suspended until the corporation disposes of the passive activity or generates passive income to absorb it.

A Lower Ceiling on Retained Earnings

Corporations that retain earnings beyond the reasonable needs of the business face a 20 percent penalty tax on accumulated taxable income under Section 531.⁸ This applies on top of the regular corporate income tax.

Personal service corporations get a smaller cushion. Their accumulated earnings credit, meaning the minimum they can retain without triggering the tax, is $150,000, compared to $250,000 for most other corporations. For a successful law firm or medical practice, that ceiling comes fast. Any accumulation beyond it needs a documented business justification such as planned expansion, equipment purchases, or anticipated legal liabilities. Vague references to future needs won’t hold up if the IRS challenges the accumulation.

The QBI Deduction and Specified Service Businesses

The personal services classification also touches pass-through entities through Section 199A’s qualified business income deduction. Originally set to expire after 2025, the deduction was made permanent by the One Big Beautiful Bill Act, and it allows eligible business owners to deduct up to 20 percent of qualified business income.⁹

The deduction phases out and disappears entirely for specified service trades or businesses once the owner’s taxable income crosses certain thresholds. For 2026, the phase-out begins around $200,000 for single filers and $400,000 for married couples filing jointly. The deduction shrinks progressively above those levels and is fully eliminated near $275,000 for singles and $550,000 for joint filers.

The specified service category largely overlaps with the Section 448 list, but not perfectly. Health, law, accounting, actuarial science, performing arts, and consulting are all included. Section 199A also brings in athletics, financial services, and investing or investment management, none of which appear on the Section 448 list.⁹

The biggest surprise for many professionals: engineering and architecture are explicitly excluded from the specified service definition under Section 199A, even though they appear on the Section 448 list. An engineering firm organized as an S corporation can claim the full 20 percent QBI deduction regardless of the owner’s income level. A law firm organized the same way cannot, once the owner’s income clears the thresholds. For high earners choosing between entity structures, that difference can translate to tens of thousands of dollars a year.

Below the phase-out thresholds, the distinction doesn’t matter. All qualifying business income gets the deduction regardless of industry. The limitation only bites for owners whose total taxable income pushes into or above the phase-out range.

Choosing a Structure Around These Rules

The personal services label touches nearly every tax decision a professional business makes. Choosing between a C corporation, an S corporation, and a partnership means weighing PSC restrictions against Section 199A limitations, entity-level taxes, and self-employment tax exposure. There is no single best structure. The right choice depends on income level, the number of owners, whether the business holds passive investments, and how much income the owners plan to retain in the entity.

A few patterns tend to hold. Professionals with income below the Section 199A thresholds often benefit from pass-through structures that allow the QBI deduction. Those above the thresholds, particularly in law, medicine, and consulting, need to weigh whether a C corporation’s flat 21 percent rate, combined with PSC restrictions and eventual double taxation on distributions, still beats the higher individual rates on pass-through income. Engineers and architects in the same income range face a different calculation, since their pass-through income qualifies for the QBI deduction at any income level.

Whatever the structure, professionals in these eight fields should treat the PSC rules as a starting point for tax planning rather than an afterthought. Failing the function or ownership test mid-year, triggering Section 269A reallocation, or stumbling into the accumulated earnings tax are all problems that can be prevented with the right structure and documentation from the start.

1
Office of the Law Revision Counsel. 26 USC 269A – Personal Service Corporations Formed or Availed of to Avoid or Evade Income Tax
2
Office of the Law Revision Counsel. 26 USC 448 – Limitation on Use of Cash Method of Accounting
3
Internal Revenue Service. Entities 5 – Personal Service Corporation
4
Internal Revenue Service. Publication 542, Corporations
5
Office of the Law Revision Counsel. 26 USC 441 – Period for Computation of Taxable Income
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eCFR. 26 CFR 1.280H-1T – Limitation on Certain Amounts Paid to Employee-Owners by Personal Service Corporations Electing Alternative Taxable Years
7
Office of the Law Revision Counsel. 26 USC 469 – Passive Activity Losses and Credits Limited
8
Office of the Law Revision Counsel. 26 USC 531 – Imposition of Accumulated Earnings Tax
9
Office of the Law Revision Counsel. 26 USC 199A – Qualified Business Income