If you qualify for the Disability Tax Credit today, you may also be owed money for years you already qualified but never claimed. Here is how far back it goes, and how to ask for it.
You never have to pay a percentage of your refund to claim this. It is free and you can do it yourself.
Curious what your back years could be worth?
See your estimate with our free calculator →The CRA can normally adjust a tax return for up to 10 years after the fact. This is called the taxpayer relief provision. It means a request made in 2026 can reach all the way back to the 2016 tax year, if your Disability Tax Credit is approved for those years.
How many years you can claim depends on the start date your doctor writes in Part B of Form T2201. If they write 2016, you can potentially claim all 10 years. If they write 2023, you can only go back to 2023. This is why it is worth a real conversation with your doctor about the earliest accurate year, not just the year you happened to apply.
Form T2201 has a box asking the CRA to automatically adjust your past returns using the approved start date. Tick this box. Without it, you may need to file separate adjustment requests for each past year yourself.
The Disability Tax Credit is non-refundable, which means it can only reduce tax that was actually paid. If the person with the disability paid little or no tax in a given year, the unused amount can usually be transferred to a supporting family member instead, such as a parent, spouse, or adult child who helped support them. This transfer is claimed on line 31800 of the family member's return, or line 32600 if it is a spouse. The refund then goes to whoever paid the tax.
If a child is approved for the Disability Tax Credit, the family may also be owed retroactive Child Disability Benefit (CDB) payments. The CRA automatically adds the CDB to the Canada Child Benefit for the current benefit year and the two previous benefit years. For years older than that, you need to ask the CRA in writing.
How much could this add up to? For an adult approved back the full 10 years, the combined federal and provincial credit can range roughly from $17,000 to $28,000, depending on the province. Children can be owed more once the Child Disability Benefit is included. Use the calculator above for a number based on your own province, years, and situation.
We'll email you the plain-language guide to applying yourself: the T2201 form, what your doctor fills in, and how to ask the CRA for your back years. One email, no spam.
This guide is for information only and is not tax, legal, or medical advice. Retroactive amounts depend on the tax paid each year, the province, and what the CRA approves. Verified July 2026.