Yes, a professional corporation can be an S corp. Federal tax law does not treat a professional corporation any differently from a standard business corporation when it comes to S corp eligibility — the IRS looks at the structural requirements in Internal Revenue Code Section 1361, not at whether the shareholders hold professional licenses.1Internal Revenue Service. S Corporations If your PC meets those requirements and files Form 2553 on time, the election is available to you, and combining it with the PC form lets licensed professionals keep the liability protections their state requires while avoiding the double taxation that comes with C corp status.
What Your PC Has to Look Like to Qualify
Every corporation electing S status has to satisfy all of the requirements in IRC Section 1361(b)(1). A professional corporation qualifies when it is:
- A domestic corporation, organized under U.S. federal or state law.
- Owned by no more than 100 shareholders. Family members across up to six generations can elect to be counted as a single shareholder.
- Owned only by eligible shareholders — individuals who are U.S. citizens or resident aliens, plus certain estates and qualifying trusts. Partnerships, other corporations, and nonresident aliens cannot hold shares.
- Limited to one class of stock, meaning every share carries identical rights to distributions and liquidation proceeds. Differences in voting rights alone do not create a second class.
- Not on the list of ineligible corporation types, which includes certain financial institutions using the reserve method for bad debts, insurance companies taxed under Subchapter L, and domestic international sales corporations.
Professional corporations are not on the ineligible list.2Office of the Law Revision Counsel. 26 U.S. Code 1361 – S Corporation Defined Meet the five conditions above, file the election, and your PC gets pass-through tax treatment.
Where S Corp Rules and PC Licensing Rules Interact
Federal shareholder rules and state PC ownership rules run on parallel tracks, and for a licensed-professional firm they usually reinforce each other. The IRS requires every S corp shareholder to be an individual who is a U.S. citizen or resident alien (or an eligible estate or trust). State professional corporation statutes layer a second filter on top: every shareholder must also hold an active license in the PC’s field. A law firm PC has to be owned by licensed attorneys, a medical PC by licensed physicians, and so on.
The combined effect is that ownership in a professional S corp is restricted to a small pool of licensed, U.S.-based individuals. That narrow pool actually makes it easier to stay under the 100-shareholder cap and to keep out the kinds of owners — corporations, partnerships, foreign nationals — that would blow up the S election.
If a Shareholder Loses Their License
If a PC shareholder becomes disqualified from practicing, most state laws require that person to give up their shares, typically through a mandatory buyback. The transfer has to go to someone who is both licensed under state law and eligible to hold S corp stock under federal law. If the shares briefly land in ineligible hands, the S election can terminate on the date of the disqualifying event.
The practical protection is a shareholder or buy-sell agreement that spells out where the shares go the moment a triggering event happens. If a disqualifying transfer does slip through, the IRS can treat the termination as inadvertent and preserve the election, provided the corporation fixes the problem within a reasonable time and all shareholders agree to any required tax adjustments.3eCFR. 26 CFR 1.1362-4 – Inadvertent Terminations and Inadvertently Invalid Elections
Trust Ownership
Certain trusts can hold S corp shares under federal law — most commonly Qualified Subchapter S Trusts and Electing Small Business Trusts. State PC statutes may or may not allow trust ownership at all, and some allow it only if the trust beneficiary personally holds the professional license. Confirm your state’s rule before moving PC shares into any trust for estate planning.
The One Class of Stock Rule Can Bite Partnerships
The single-class-of-stock requirement is the one that trips up professional firms wanting to give founding partners different economic rights than newer shareholders. Every outstanding share has to carry identical rights to distributions and liquidation proceeds. You can vary voting power — some shareholders can have more votes per share than others — without violating the rule.2Office of the Law Revision Counsel. 26 U.S. Code 1361 – S Corporation Defined But a shareholder agreement, bylaw, or side deal that gives certain owners a larger share of profits or priority in liquidation can be treated as creating a second class of stock, which would terminate the election.
Loans from shareholders to the corporation generally do not create a second class as long as they qualify as straight debt: a fixed repayment amount, an interest rate not tied to profits, and no ability to convert the debt into stock.2Office of the Law Revision Counsel. 26 U.S. Code 1361 – S Corporation Defined
How to File the Election
The filing document is IRS Form 2553, Election by a Small Business Corporation. Your PC needs an Employer Identification Number before you submit — you can apply online at IRS.gov and receive one immediately.4Internal Revenue Service. Instructions for Form 2553
Form 2553 asks for the corporation’s legal name, date of incorporation, state of incorporation, and the tax year for which the election should take effect. The shareholder consent section is where most filings go wrong. Every person who held shares at any point during the election period has to provide their legal name and home address, Social Security number (or EIN for an estate or trust), the number of shares owned and the date acquired, and a signature consenting to the election. Missing one signature invalidates the filing.4Internal Revenue Service. Instructions for Form 2553
The Deadline
Form 2553 has to be filed no later than two months and 15 days after the start of the tax year in which you want the election to take effect. For a calendar-year PC, that is March 15. You can also file at any time during the tax year before the one in which the election should begin.5Internal Revenue Service. Instructions for Form 2553
The IRS accepts Form 2553 by mail or fax only. Send the original — not a copy — to the service center for your corporation’s principal business location, or fax it to the number in the instructions.6Internal Revenue Service. Where to File Your Taxes for Form 2553 Keep proof of submission. The IRS recognizes certified or registered mail receipts with a timely postmark, a stamped-accepted form, a form with a stamped IRS-received date, or a letter from the IRS confirming acceptance.5Internal Revenue Service. Instructions for Form 2553 Once processed, the IRS mails a CP261 notice confirming the election. File it with your permanent records.7Internal Revenue Service. Understanding Your CP261 Notice
If You Missed the Deadline
Revenue Procedure 2013-30 provides late election relief. Your PC has to have intended S corp classification as of the effective date, the only reason the election failed has to be the late filing, there has to be reasonable cause for the delay, and relief has to be requested within three years and 75 days after the intended effective date. Every person who was a shareholder at any point from the intended effective date through the date the late form is filed has to sign and confirm they reported income consistent with S corp treatment.8Internal Revenue Service. Revenue Procedure 2013-30
A broader exception drops the three-year-and-75-day cutoff entirely if the corporation and all shareholders have consistently filed as if the election were in place, at least six months have passed since the first S corp return was filed, and the IRS has not contacted anyone about the corporation’s status in the meantime.8Internal Revenue Service. Revenue Procedure 2013-30
The Reason Most PCs Elect: Salary and Distributions
The financial case for a professional corporation electing S corp status is employment tax savings. A PC taxed as a C corporation, or a professional operating as a sole proprietor, pays Social Security and Medicare taxes on all earnings — 15.3 percent combined on wages up to the Social Security wage base of $184,500 in 2026, and 2.9 percent on earnings above that.9Social Security Administration. Contribution and Benefit Base
Under S corp treatment, the owner splits income into salary and distributions. Only the salary runs through payroll and gets hit with employment taxes. Distributions are still subject to income tax but not to Social Security or Medicare tax. For a professional earning $200,000 in net business income, shifting a meaningful portion to distributions saves thousands of dollars each year.
The limit is the reasonable compensation rule. Every S corp shareholder who works in the business has to receive a salary that reflects what someone in a similar role and industry would earn before taking any distributions. The IRS can reclassify distributions as wages and assess back employment taxes, penalties, and interest if it decides the salary was unreasonably low, and courts have upheld that authority.10Internal Revenue Service. S Corporation Compensation and Medical Insurance Issues Set a defensible number.
The Fringe Benefit Tradeoff for Owner-Practitioners
Anyone owning more than 2 percent of the stock or holding more than 2 percent of the voting power in an S corp is a “2-percent shareholder” for fringe benefit purposes. The IRS treats these shareholders more like self-employed partners than employees, which changes the tax treatment of benefits the PC provides.11Internal Revenue Service. Employers Tax Guide to Fringe Benefits
Health insurance premiums the S corp pays for a 2-percent shareholder have to be added to the shareholder’s W-2 as taxable wages in Box 1, though not in Boxes 3 or 5, so they escape Social Security and Medicare taxes. The shareholder then takes an above-the-line deduction for those premiums on their personal return, provided their spouse was not eligible for a subsidized plan through another employer.10Internal Revenue Service. S Corporation Compensation and Medical Insurance Issues
Several fringe benefits that are tax-free for ordinary employees become taxable when the recipient is a 2-percent shareholder: group-term life insurance, accident and health benefits, meals provided on business premises, qualified transportation benefits, adoption assistance, and cafeteria plan benefits.11Internal Revenue Service. Employers Tax Guide to Fringe Benefits If your PC provides any of these, the value has to be included in the shareholder-employee’s wages.
How the Election Can End
An S corp election can end three ways. Shareholders holding more than half the shares can voluntarily revoke it; a revocation filed by the 15th day of the third month of the tax year takes effect at the start of that year, and later revocations take effect the following year unless a future date is specified.12Office of the Law Revision Counsel. 26 U.S. Code 1362 – Election, Revocation, Termination The election can terminate automatically if the corporation stops meeting any eligibility requirement, effective on the date of the disqualifying event. And it can terminate after three consecutive years of excess passive investment income combined with accumulated C corp earnings and profits.
For a working professional corporation, the middle scenario is the one to watch. A shareholder losing their license, transferring shares to an unlicensed person, or bringing in an ineligible investor can each end the election immediately. A well-drafted shareholder agreement is the best protection, and if a disqualifying event still happens, the corporation can request a private letter ruling asking the IRS to treat the termination as inadvertent — available only if the problem is fixed promptly and shareholders consent to any required adjustments.3eCFR. 26 CFR 1.1362-4 – Inadvertent Terminations and Inadvertently Invalid Elections
Extra Rules if You Are Converting From a C Corp
Everything above assumes you are electing S status at formation or shortly after. If your PC has been operating as a C corporation and is converting, two additional rules apply. Any built-in gain on appreciated assets held at the time of conversion is subject to a corporate-level tax if the asset is sold within a five-year recognition period.13Office of the Law Revision Counsel. 26 U.S. Code 1374 – Tax Imposed on Certain Built-In Gains And if more than 25 percent of the S corporation’s gross receipts in a year come from passive investment income while it still carries accumulated C corp earnings and profits, a special tax at the highest corporate rate applies to the excess, with automatic termination after three consecutive years.14Office of the Law Revision Counsel. 26 USC 1375 – Tax Imposed When Passive Investment Income of Corporation Having Accumulated Earnings and Profits Exceeds 25 Percent of Gross Receipts Distributing the accumulated C corp earnings promptly after the S election removes the passive income risk.
State Follow-Up
Most states automatically follow the federal S corp election — once the IRS accepts your Form 2553, the state recognizes the election without a separate filing. A minority require their own S corp election form. Check with your state tax agency after your federal election is accepted to confirm what, if anything, they need. Some states also impose entity-level, franchise, or minimum taxes on S corps regardless of pass-through status, which can shrink the savings you were counting on.