What medical expenses can I claim on my Ontario tax return?

Canada's Medical Expense Tax Credit (METC) is a non-refundable federal and provincial credit for eligible medical costs paid during the year. Ontario's ON428 form has a corresponding provincial medical expense credit, so eligible expenses reduce both your federal and Ontario provincial tax.

Eligible expenses are broad and include prescription medications, dental work (excluding purely cosmetic procedures), vision care (glasses, contacts, laser surgery), hospital bills, certain medical devices, attendant care, and amounts paid for certain therapies. Premiums paid to private health insurance plans also qualify. The list of eligible expenses is defined in the federal Income Tax Act, and the CRA publishes a detailed guide. Cosmetic procedures, vitamins, and over-the-counter medications generally do not qualify unless prescribed.

The credit is calculated on the amount by which your total eligible medical expenses exceed the lesser of 3% of your net income or a fixed annual threshold (which is adjusted periodically). Because there is a floor, small amounts may produce little or no credit. You can combine your expenses with those of a spouse or dependent to maximize the claim, and you can choose any 12-month period ending in the tax year to maximize the amount over the floor.