Disability Tax Credit Calculator

How the 10-year retroactive DTC refund works

Once the CRA approves your Form T2201 (Disability Tax Credit Certificate), you're not limited to claiming the credit going forward. The CRA lets you file a T1 Adjustment Request (T1-ADJ) — or ask them to reassess directly — for up to 10 tax years back from the year you make the request. Filing in 2026 means the oldest year you can typically reach back to is 2016, and the newest completed tax year available is 2025.

Each tax year is reassessed separately, using that year's federal base amount and lowest tax rate, plus that year's provincial or territorial amount and rate — not today's numbers. That's why the calculator below builds a full year-by-year table instead of a single multiplied estimate: rates and amounts moved noticeably over the period (for example, the federal rate dropped from 15% to 14.5% partway through 2025, and Alberta's provincial rate fell from 10% to 8% starting in 2025).

Who can claim it — yourself, or a transfer to a supporting relative

The DTC belongs to the person with the disability. If that person doesn't have enough taxable income to use the full non-refundable credit in a given year, the unused portion transfers to a spouse or common-law partner, or to a parent, grandparent, child, or other relative who provides for the person's basic needs (line 31800 federally, with an equivalent provincial line). This matters a lot for retroactive claims: a low-income adult or a minor child rarely has enough tax payable on their own to use ten years of credit, so most of the real dollar value usually flows through a supporting family member's return.

The DTC is non-refundable — the estimate assumes tax payable

This is the single biggest caveat: the Disability Tax Credit is a non-refundable credit. It can reduce your federal and provincial tax payable down to zero, but it cannot create a refund beyond that — and it can't be carried forward if a given year's tax payable was too low to absorb it. The totals below assume the claimant (or the relative claiming the transfer) had enough tax payable in each of the 10 years to use the full credit. If income was low or zero in some of those years, your real refund will be smaller than the headline total for those specific years.

The child supplement, and why it shrinks with child-care claims

A person under 18 at the end of the tax year gets an additional child supplement on top of the base federal amount, and on top of the base provincial amount in most (not all) jurisdictions. In 2025, an eligible child in Ontario adds roughly $1,160.88 to that single year's credit versus an adult claim.

The under-18 supplement is reduced once child care or attendant care expenses claimed for that child pass roughly $3,464-$3,533 a year (threshold varies by year) and eliminated above a second threshold of roughly $9,378-$9,565 a year. Does not apply in Saskatchewan (no separate supplement there).

Saskatchewan is a documented exception: it has no separate child supplement — the single "disability amount" line applies the same whether the claimant is an adult or a child. A 3-year Saskatchewan claim (2023–2025) totals $8,069.93 regardless of the child-supplement checkbox.

Not the same as the Canada Disability Benefit

The DTC (this calculator) is a tax credit claimed on your income tax return — its value depends on tax payable and delivers no cash if there's none owing. The Canada Disability Benefit is a separate, newer federal cash benefit program with its own eligibility and application process (it does generally require DTC approval as a gateway, but the payment itself is independent of tax owed). Don't confuse the two, or assume this retroactive-refund estimate includes Canada Disability Benefit payments — it doesn't.