A busy family doctor and a corporate lawyer earning the same income end up with very different tax bills, and the gap has almost nothing to do with how hard either of them works. It comes down to structure, and for physicians in particular, some of the standard playbook does not apply the way it does for other incorporated professionals.
Incorporating Changes What Counts as Tax Planning at All
Most provinces allow physicians to incorporate through a professional corporation, and doing so is often the single biggest lever available. A professional corporation pays federal tax of 9 percent on its first $500,000 of active business income, well below the personal rates a sole proprietor pays once income climbs into the higher brackets. Profit left inside the corporation stays untaxed personally until it is paid out, which lets a physician build savings inside the practice during high-earning years rather than pulling everything out and paying personal tax on it immediately.
The mechanics of the small business deduction, the passive income grind that kicks in above $50,000 of investment income, and the salary versus dividend decision are the same ones every incorporated business owner navigates, and our guide to corporate tax planning covers them in full. What changes for a medical practice is everything downstream of that decision, starting with who else can share in the income.
Splitting Income With Family Gets Harder Once the Corporation Is a Professional One
A common assumption is that giving a spouse or adult child shares in the practice works the same way it does for any other family business. For most corporations, an adult family member who owns at least 10 percent of the voting shares and value can receive dividends without the tax on split income rules applying, through what the Income Tax Act calls the excluded shares exception.
That exception is written to exclude professional corporations by name. A physician’s spouse can hold shares, but dividends paid on them do not qualify for the same relief a non-professional business owner’s spouse would get, and the CRA taxes them at the top personal rate regardless of the spouse’s other income. This has been the rule since the 2018 expansion of the tax on split income rules, and it catches physicians more often than other incorporated professionals precisely because the exception was built to exclude them specifically.
The rules are not a total block on family involvement. Salary paid for real, ongoing work in the practice is not split income no matter who receives it, and dividends can still qualify as an excluded amount if the family member is genuinely engaged in the business on a regular basis. What the rules close off is the passive version, shares held quietly by a spouse who does not work in the practice, purely to move income into a lower bracket.
Most of the Practice's Revenue Is GST/HST Exempt, But Not All of It
Basic health care services performed by a licensed physician are exempt from GST/HST, and that exemption covers the bulk of what most practices bill. It is easy to assume this means a medical practice never has to think about GST/HST registration at all, and for many physicians that is close to true.
It stops being true the moment a practice does work that falls outside that exemption. Medical-legal reports, executive health assessments not tied to treatment, and other services not covered by a provincial health plan are taxable supplies, and they are treated like any other business income for GST/HST purposes. A physician whose taxable, non-exempt billings cross $30,000 in a single calendar quarter or over four consecutive quarters has to register and start charging GST/HST on that portion of their work, even though their core patient care stays exempt. Practices with a mix of clinical and non-clinical work are the ones most likely to miss this, since the exempt majority of their billing can make the taxable slice easy to overlook.
Retirement Savings Follow the Structure, Too
An incorporated physician’s RRSP room is driven by the salary they pay themselves, not by the corporation’s overall profit, so the salary versus dividend decision above also decides how much retirement room builds up each year. A physician who takes most of their income as dividends to stay in a lower personal bracket may find their RRSP room barely grows, which is worth weighing against the tax savings dividends provide in the year they are paid. Our guide to retirement tax planning goes into how that room gets used once it exists.
The Right Structure Depends on the Practice, Not Just the Income
Two physicians earning the same amount can end up with very different answers on incorporation, income splitting, and GST/HST registration, depending on how their billing splits between exempt and taxable work and who else is genuinely involved in the practice. Your Modern Accountant works with physicians and other health professionals across Canada through our tax planning service to sort out which of these actually apply before a filing deadline forces the decision.