Professional Medical Corporations: The Physician’s Entity, From Solo Practice to Platform

Where is your practice right now?

Forming: you’re incorporating your first practice and want it built correctly from the articles up. Growing: you’re adding a partner, an associate track, or a second location, and the handshake-era governance needs real documents. Dealing: you’ve been approached by a platform, an MSO, or a buyer — or you’re the physician-owner a structure is being built around — and you need to know what you’re actually agreeing to. This page serves all three; the lifecycle table below shows where the work concentrates at each stage.

What is a professional medical corporation?

A professional medical corporation is the Moscone-Knox entity for physician practice: formed under California’s professional-corporation framework and the medical profession’s provisions of the Business and Professions Code, subject to Medical Board rules on naming and operation.

It is the practice: it employs or contracts the clinicians, owns the patient relationships and records, holds the payer contracts, bills for professional services, and makes every clinical decision. Whatever grows around it — associates, locations, a management company, a platform deal — the medical corporation remains the entity where medicine legally lives, and the entity whose governance determines whether the physicians actually control it.

Ownership and leadership rules

Licensed physicians must hold the majority of a professional medical corporation’s shares. A statutory list of other licensed professionals — categories include podiatrists, psychologists, registered nurses, physician assistants, and other listed professions — may hold minority interests, capped in aggregate percentage and in number relative to physician shareholders (verify the current Corporations Code § 13401.5 list and limits at publication). Non-licensees may never hold shares. Directors and officers must generally satisfy licensure requirements, with narrow exceptions for small corporations (verify current scope).

For physicians, two practical readings of those rules:

• Your cap table is a compliance document. Every share moves only to qualified licensees, which is why certificates carry restriction legends and why transfer, death, divorce, and license-loss scenarios need mechanics drafted in advance — not improvised at the worst possible moment.
• Majority means governance, not just economics. In any structure involving outside parties, the physician majority is what California expects to be real — exercising actual authority over the clinical enterprise. That expectation follows you into every deal discussed below.

Group practices: where the real governance work lives

Most physician-practice disputes we see aren’t regulatory — they’re internal, and they trace to the same gap: a group that grew on collegiality and never papered the questions that only matter when someone disagrees, retires, divorces, dies, or underperforms. The core document set for a multi-physician corporation:

• Shareholder/buy-sell agreement. Who can own shares, at what valuation shares move, what triggers a mandatory transfer (death, disability, retirement, license loss, termination), and how it’s funded. This is the group’s constitution.
• Compensation methodology. Productivity, equal-share, or hybrid — written down, with a defined process for changing it. Unwritten comp formulas are deferred disputes.
• Admission and exit terms. The associate-to-partner path, buy-in mechanics, and what departing physicians take (and don’t) — drafted against California’s limits on restrictive covenants (Business and Professions Code § 16600 reaches further here than out-of-state templates assume).
• Deadlock and dispute mechanics. Especially for two-physician corporations, where a 50/50 split with no tiebreaker is a standstill waiting for its occasion.

The right time for this set is before the second shareholder — while everyone still agrees. The second-best time is now.

The physician’s chair in an MSO deal

Elsewhere on this site the MSO model is explained from the builder’s side. Here’s the view from your chair — the physician who owns the PC in the structure:

You are the load-bearing wall. The entire arrangement is lawful because a physician genuinely owns and governs the clinical enterprise. That makes your ownership rights, your authority, and your exit terms the most scrutinized elements of the deal — by regulators, and eventually by any buyer’s diligence team.

Read the deal as one document. The MSA, the stock-transfer restriction agreement, and any continuity/succession agreement operate together. What the MSA gives you, the side agreements can quietly take back — replacement-at-will mechanics, nominal-value share transfers, economics that leave the PC hollow. (The framework: Friendly PC-MSO Model → · MSA →.)

Negotiate the disagreement scenario. The single most revealing question in any platform deal: what happens if you exercise independent clinical judgment the MSO dislikes? If the honest answer is “I’d be replaced,” the structure has a problem that better recitals won’t fix — and in California’s current environment, that problem is increasingly the first thing examined.

None of this makes platform deals bad. Well-built ones give physicians capital, infrastructure, and relief from business operations while keeping clinical control where the law puts it. The physician’s job is to make sure the one on the table is well-built — before signing.