How to Form a California Medical Corporation — and the Rules Most Guides Get Wrong

A California physician who wants an entity gets exactly one real choice: the professional medical corporation. LLCs can't render professional services in California, and the corporate-practice-of-medicine doctrine — Business and Professions Code section 2400's rule that corporations “shall have no professional rights, privileges, or powers” — means an ordinary corporation can't employ physicians to practice either. The medical corporation under the Moscone-Knox Act is the vehicle the law built for the job.

The entity itself is covered in our California Professional Corporations pillar guide. This piece is the physician-specific layer — and it corrects three things the top-ranking articles still get wrong. Orientation, not legal advice for your situation.

Who can own shares: the list that changed in 2023#

A medical corporation must be majority-owned by physicians — licensed shareholders of the corporation's own profession always keep at least 51%. But Corporations Code section 13401.5(a) lets fifteen categories of allied licensees hold minority stakes:

Licensed doctors of podiatric medicine · licensed psychologists · registered nurses · licensed optometrists · licensed marriage and family therapists · licensed clinical social workers · licensed physician assistants · licensed chiropractors · licensed acupuncturists · naturopathic doctors · licensed professional clinical counselors · licensed physical therapists · licensed pharmacists · licensed midwives · licensed occupational therapists.

That last category — occupational therapists — was added effective 2023, and the articles ranking for this topic largely still carry outdated pre-2023 lists. Two statutory limits sit over the whole arrangement, and the second one is the one group practices miss:

• The 49% cap: all allied-licensee shares combined cannot exceed 49% of the corporation's total shares.
• The headcount cap: the number of allied shareholders cannot exceed the number of physician shareholders. One physician owner means at most one allied owner, no matter how small the stake.

Two frequently-asked cases: a physician assistant can hold a minority medical-corporation stake — and separately, PAs have their own corporation type (whose name, unlike a medical corporation's, must by statute contain the words “physician assistant”). And a nurse practitioner can hold a minority stake as a registered nurse — NP certification rides on an RN license — or own up to 100% of a nursing corporation instead.

Officers and directors: stricter than the default#

Moscone-Knox's small-practice accommodations apply — a solo-shareholder medical corporation needs one director (the physician), who serves as president and treasurer, and a two-shareholder corporation needs two directors holding the four offices between them. But medicine adds its own rule: under Business and Professions Code section 2408, every shareholder, director, and officer of a medical corporation must be a licensed person, except an assistant secretary or assistant treasurer. The statute's pressure valve is titles: an unlicensed practice manager can carry an administrative title — chief executive officer, executive vice president — without being a corporate officer. That's how a well-run practice gives its administrator real authority without violating the licensure rule.

The name: when you need the $70 permit — and when you don't#

California gives medical practices a clean naming rule with a sharp edge. A corporation practicing under a name that is a physician owner's own name — “Jane Rivera, M.D., Inc.” — needs no permit at all. Any other name requires a fictitious-name permit from the Medical Board under Business and Professions Code sections 2285 and 2415 — and here's the edge: that's true even when the name is the corporation's legal name. A practice legally incorporated as “Coastal Wellness Medical Group” still needs the permit, because the test is whether the public-facing name is other than the licensee's own, not whether the Secretary of State accepted it.

The mechanics: $70 application, $50 renewal every two years ($20 delinquency fee), and the permit must be in hand before practicing under the name — processing historically runs several weeks with no expediting, so file it alongside the Articles, not after the signage order. One myth worth retiring: no statute requires a medical corporation's name to contain “Medical Corporation” or “M.D., Inc.” — those are customary formats. The name rules that actually bind are the own-name-or-permit rule and the Medical Board's bar on deceptive or misleading names.

The registration step that doesn't exist#

Several high-ranking guides still instruct new medical corporations to “register with the Medical Board of California.” There is no such registration: medical corporations are on the statutory list of professional corporations exempt from any certificate of registration, and the Board operates no corporate-registration program. The only Medical Board filing most practices will ever make is the fictitious-name permit above. The practical formation sequence is the standard professional-corporation path — ARTS-PC articles ($100), bylaws with the licensed-shareholder and transfer restrictions, the annual Statement of Information, the S-election decision with your CPA — walked step-by-step in the pillar guide, including the first-year rule most articles miss: a new California corporation owes no $800 minimum franchise tax in its first taxable year, permanently, under Revenue and Taxation Code section 23153(f)(1).

Employing clinicians — and the MSO line after SB 351#

A medical corporation may employ physicians, physician assistants, nurse practitioners, and any other licensee under the healing-arts framework — the statute says so directly. What California prohibits is the inverse: unlicensed entities employing physicians to practice medicine. That's the corporate-practice doctrine, and since January 1, 2026 it has statutory teeth aimed at investors: SB 351 bars private equity groups and hedge funds involved with physician practices from interfering with professional judgment — diagnostic testing, referrals, treatment decisions, patient-volume targets — and from controlling the practice's medical records, clinical hiring and firing, payor contracting, or coding and billing. Contract provisions that cross the line are unenforceable, and the Attorney General can sue.

Management services organizations remain lawful on the other side of that line: administrative support, facilities, nonclinical staffing, IT, billing execution under decisions the physicians make. If your practice has — or is considering — an MSO relationship, the management agreement should be drafted against SB 351's enumerated list, with the medical corporation's governance documents keeping clinical control demonstrably with the licensees.

The checklist, physician edition#

• Entity: professional medical corporation — not an LLC, not an ordinary corporation.
• Ownership: physicians ≥51%; allied owners only from the fifteen-category list, under both the 49% and headcount caps.
• Governance: every shareholder, director, and officer licensed (assistant secretary/treasurer excepted); unlicensed administrators get titles, not offices.
• Name: own name needs no permit; anything else — including the legal corporate name — needs the Medical Board's $70 fictitious-name permit before use.
• No Medical Board corporate registration — the step doesn't exist.
• Transfer discipline: shares move only to licensed hands, with 90-day (disqualification) and six-month (death) divestiture clocks — the reason a medical corporation needs its buy-sell from day one.
• Tax: S election with your CPA at formation; no $800 minimum in year one.