— Quick Answer
- →The Trillium Drug Program (TDP) is Ontario’s income-tested drug plan for residents with a valid OHIP number whose prescription costs are high relative to household income.
- →Your annual deductible is approximately 4% of your household’s net income from line 23600 of the most recent CRA Notice of Assessment, minus any RDSP withdrawals reported on line 12500.
- →The program year runs August 1 to July 31, and the deductible is split into four quarterly amounts; once a quarter’s deductible is paid, you pay up to $2 per prescription for the rest of that quarter.
- →Apply by September 30 to be reimbursed for eligible prescriptions filled back to August 1 of the same program year.
- →Every adult member of the household must file their Canadian income tax return on time for enrolment to renew automatically.
— Why prescription costs in Ontario hit working adults hardest
If you are between 25 and 64 and your workplace does not offer a drug plan, Ontario’s public drug coverage can feel out of reach. The Ontario Health Insurance Plan (OHIP) pays for doctor visits and hospital care, but not for prescriptions filled outside a hospital.
OHIP+, the program that used to cover everyone under 25, was narrowed in April 2019 and now applies only to Ontarians 24 and under without private drug insurance. The Ontario Drug Benefit (ODB) covers seniors 65 and over and people on social assistance. Working-age adults in between can fall into a gap.
That gap is what the Trillium Drug Program is designed to close. It is an income-tested plan, which means your deductible scales with what your household can afford rather than with how sick you are.
— Quick start: pick your path
Use the path that matches your household most closely:
- →Single filer, no workplace drug plan: apply directly. Your line 23600 net income alone drives the deductible.
- →Dual-income couple: both spouses share the same TDP household, both incomes combine, and both must file on time.
- →Retiree household: TDP can still apply if you are under 65 or a younger spouse anchors the household.
- →Sole proprietor: net self-employment income after expenses flows to line 23600, which usually lowers the deductible.
- →Incorporated owner-manager: only the salary or dividends you draw count. Retained corporate earnings do not.
Households with several income streams may also find this guide useful: optimizing tax filing across multiple income sources.
— How the deductible is calculated from line 23600
The formula in plain English: take everyone’s line 23600 figure, add the household totals together, subtract RDSP withdrawals on line 12500, and multiply by roughly 4%.
Worked example: a couple with combined line 23600 net income of $60,000 would expect an annual deductible of $60,000 × 4% ≈ $2,400, or about $600 per quarter. A single filer at $35,000 lands at roughly $1,400 annually.
Two notes typically catch people by surprise. The deductible varies modestly with household size, so the confirmation letter may differ slightly from a pure 4% calculation. And the income that matters is what you reported, not what you have earned this calendar year.
Reviewing what flows to line 23600 before you file is straightforward: see our tax-season prep guide.
— Worked deductible examples by household type
Because the deductible is a fixed percentage, the dollar figure scales predictably with income. The table below illustrates approximate annual and quarterly deductibles for five common Ontario household profiles. These are illustrative only — the Ministry of Health issues the binding deductible in your confirmation letter.
| Household profile | Approx. line 23600 net income | Approx. annual deductible | Approx. quarterly |
|---|---|---|---|
| Single working adult, no benefits | $45,000 | $1,800 | $450 |
| Dual-income couple, both employed | $95,000 | $3,800 | $950 |
| Retiree couple under 65, pensions and CPP | $70,000 | $2,800 | $700 |
| Sole proprietor, after expenses | $55,000 | $2,200 | $550 |
| Incorporated professional, drawing dividends | $80,000 | $3,200 | $800 |
The sole-proprietor row sits below the incorporated row even when the businesses earn similar revenue. Business expenses reduce net self-employment income on the personal return, while incorporated owners control how much salary or dividend they actually draw into line 23600.
Sole proprietors planning year-end can deepen this with our guide on tax deductions for Canadian sole proprietors.
— Step-by-step: applying for TDP and staying enrolled
The application path is straightforward when you take it in order:
- 1Confirm OHIP coverageEvery household member needs a valid OHIP number and must not already be covered by the Ontario Drug Benefit.
- 2Choose a coverage start datePick a date on or before the day of your first eligible prescription. The start date cannot be changed later.
- 3Complete the applicationUse the Ministry of Health online portal, or request a paper copy by phone.
- 4Sign the CRA consentEvery adult in the household must sign the consent so the Ministry can pull income directly from the most recent Notice of Assessment.
- 5Submit and wait for the confirmation letterThe letter states your binding annual deductible for the program year.
- 6File your taxes on time every yearOn-time filing lets the Ministry verify next year’s income without forcing you to reapply.
Apply by September 30 and eligible drug costs paid back to August 1 of the same program year can be counted toward your deductible. Apply later and you generally lose the retroactive portion.
Our stress-free tax filing master guide walks through the filing habits that keep TDP enrolment alive.
— What changes mid-year — income drops, new household members, lost coverage
Life rarely waits for a program year to start over. The Trillium Drug Program has built-in flexibility for the most common changes.
If household income has risen or fallen by 10% or more from the figure on file — job loss, parental leave, or a self-employment downturn — you can request a deductible reassessment. The new deductible takes effect at the start of the quarter in which it is recalculated, not retroactively.
Household changes matter too. Adding a spouse, removing a financially independent adult, or losing private insurance partway through the year should all be reported promptly. Premiums paid for private drug insurance can typically count as a credit toward the annual deductible.
Retirees coordinating drug coverage with RRIF withdrawals may find our ultimate retirement planning guide helpful.
— How TDP interacts with the federal medical expense tax credit
There is a quiet bonus most Ontario households miss: dollars you actually pay toward the Trillium deductible, plus the $2-per-prescription co-pay, are typically eligible medical expenses on your federal tax return. Report them on lines 33099 or 33199 of the T1.
The CRA reduces eligible medical expenses by the lesser of 3% of net income or a fixed annual threshold, so not every dollar produces a credit. The calculation is still worth running each year, especially in households with high deductibles.
Two boundaries to remember. You cannot claim amounts someone else paid on your behalf, such as a portion reimbursed by private insurance. And you cannot double-claim the same dollar through both an HSA reimbursement and the medical expense credit.
If this is your first year looking at medical expenses on a return, a ClearWealth tax filing review can confirm what is in and what is out.
| Amount | Medical expense tax credit |
|---|---|
| Out-of-pocket amounts you actually paid toward the TDP deductible | Generally eligible |
| $2 per-prescription co-pay after the quarter deductible is paid | Generally eligible |
| Portion of a prescription cost paid by private insurance, employer plan, or HSA | Not eligible |
| Drug-company patient-assistance or rebate amounts already reimbursed | Not eligible |
— Common mistakes Ontario households make with TDP
- →Treating roommates as household members when they are financially independent — the Ministry’s definition of household is narrower than ‘people living together’.
- →Forgetting to subtract RDSP withdrawals on line 12500 before applying the 4% formula, which overstates the expected deductible.
- →Missing the September 30 deadline and losing reimbursement for prescriptions filled earlier in the program year.
- →Skipping the deductible reassessment after a 10% or larger income drop.
- →Filing personal taxes late, which can break auto-renewal and force the household to reapply.
- →Claiming the full prescription cost as a medical expense after private insurance has already reimbursed part of it.
- →Ignoring the private-insurance premium credit when a spouse pays for a partial workplace plan.
— Frequently asked questions
How is the Trillium Drug Program deductible calculated?
Do I qualify for the Trillium Drug Program if I am over 25 and have no work benefits?
Does my spouse’s income count toward the Trillium Drug Program deductible?
What if I file my taxes late — will I lose Trillium Drug Program coverage?
Can I get my Trillium deductible reassessed if my income dropped this year?
Can I claim the Trillium deductible I paid as a medical expense on my tax return?
Is the Trillium Drug Program the same as the Ontario Drug Benefit or OHIP+?
What happens if I have partial private drug insurance — should I still apply?
Get clear answers on your Trillium deductible
The ClearWealth team helps individuals, sole proprietors, and incorporated professionals across Ontario coordinate their TDP deductible with the federal medical expense tax credit and their wider tax return. Book a no-obligation consultation to review your situation.
Book a ConsultationSources & References
- Government of Ontario, Get help with high prescription drug costs (Trillium Drug Program) — https://www.ontario.ca/page/get-help-high-prescription-drug-costs
- Ontario Ministry of Health, Trillium Drug Program Guide — https://forms.mgcs.gov.on.ca/dataset/3d092ae0-4efe-4b33-9a58-b935cf2728bf/resource/147dc3fa-0991-4312-aaac-d9523b472ad2/download/3693-87e_guide.pdf
- Canada Revenue Agency, Line 23600 — Net income — https://www.canada.ca/en/revenue-agency/services/tax/individuals/topics/about-your-tax-return/tax-return/completing-a-tax-return/personal-income/line-23600-net-income.html
- Canada Revenue Agency, Lines 33099 and 33199 — Eligible medical expenses — https://www.canada.ca/en/revenue-agency/services/tax/individuals/topics/about-your-tax-return/tax-return/completing-a-tax-return/deductions-credits-expenses/lines-33099-33199-eligible-medical-expenses-you-claim-on-your-tax-return.html
- Canada Revenue Agency, Line 12500 — RDSP income — https://www.canada.ca/en/revenue-agency/services/tax/individuals/topics/about-your-tax-return/tax-return/completing-a-tax-return/personal-income/line-12500-registered-disability-savings-plan-income.html
