OHIP Billing Number Transfer When Buying a Medical Practice in Ontario

If you're buying or selling a family practice, walk-in clinic, or specialist office in Ontario, it's tempting to think of the OHIP billing number as just another asset changing hands — like a lease or a piece of equipment. It isn't. An OHIP billing number is tied to a specific, individually licensed physician, not to the clinic, the corporation, or the practice's name on the door.

That distinction shapes almost everything about how a medical practice sale actually closes. The buyer physician doesn't "inherit" the seller's billing history or number; they arrive with their own, obtained independently through the Ministry of Health's physician enrolment process. Understanding this early — ideally before you sign a letter of intent — avoids a scramble in the final weeks before closing.

This article explains, in plain language, what does and doesn't transfer in a medical practice sale, and why the legal structure of the deal (share sale vs. asset sale) still matters even though the billing number itself never moves.

Why a Billing Number Can't Be Bought or Sold

An OHIP billing number is a personal identifier issued by the Ministry of Health to a physician who has met the province's enrolment and licensing requirements, including being a member in good standing with the College of Physicians and Surgeons of Ontario (CPSO). It is not:

• A corporate asset that appears on the practice's balance sheet
• A licence that can be assigned like a lease or a franchise agreement
• Something a purchase agreement can validly transfer, no matter how the clause is worded

Because of this, a purchase agreement for a medical practice should never describe the billing number itself as something being "sold." What's actually being sold is the practice — its patient roster, goodwill, equipment, lease, staff, and (if structured as a share sale) the corporation that operates it. The incoming physician separately applies for their own billing privileges.

What Actually Happens at Closing

A typical medical practice transition involves two tracks running in parallel: the legal/corporate transaction and the physician's own regulatory onboarding. Both need to be lined up so the practice doesn't have a gap in billable service.

The legal transaction

• Buyer and seller (or their corporations) sign a purchase agreement covering the assets or shares being transferred
• Due diligence covers the lease, equipment, employees, corporate records (if a share sale), and any professional corporation shareholding requirements
• Closing conditions are often drafted to be conditional on the buyer physician having active OHIP billing privileges and CPSO registration in good standing by the closing date

The physician's regulatory track

• The buyer applies to the Ministry of Health for their own billing number well in advance of closing
• CPSO registration (or a change of practice location/status, if already licensed in Ontario) needs to be current
• If the practice operates through a health profession corporation, the buyer's shareholding in that corporation needs to satisfy the ownership rules that apply to regulated health professionals — this is a separate question from the OHIP billing question and worth raising with your lawyer early

Because the buyer's own billing number depends on a Ministry process outside either party's control, purchase agreements for medical practices commonly build in flexibility around the closing date, or make closing conditional on the buyer's enrolment being confirmed.

Common Misconceptions to Avoid

• "The buyer can just bill under my number until theirs comes through." This is a compliance risk, not a shortcut — billing privileges are personal to the enrolled physician, and using someone else's number for another physician's services raises serious regulatory and billing-integrity concerns.
• "A share sale keeps the billing number with the practice." Even in a share sale, where the corporation itself changes hands, the physician actually rendering services still bills under their own personal number. The corporate structure doesn't change who the billing number belongs to.
• "This is just a paperwork detail, not a legal issue." It affects deal timing, closing conditions, and sometimes purchase price adjustments if a locum has to cover a gap — it belongs in the purchase agreement, not left as an afterthought.

Questions to Work Through Before You Sign

• [ ] Has the incoming physician started their Ministry of Health enrolment and CPSO registration process?
• [ ] Does the purchase agreement make closing conditional on active billing privileges being confirmed?
• [ ] If the practice is incorporated, does the buyer's intended shareholding meet the ownership requirements for a health profession corporation?
• [ ] Is there a plan (and, if needed, a locum) to cover any gap between the outgoing and incoming physician's billing status?
• [ ] Has patient notice and record-transfer been addressed separately from the corporate/asset transaction?

Frequently asked questions