Making the Most of the Disability Tax Credit - Unlocking Retroactive Tax Credits: Don't Leave Money on the Table ( Part 1/5)

If you have been eligible for the DTC in past years but never applied or claimed it, you may be able to receive retroactive payments. The CRA allows you to request a reassessment of your tax returns for up to 10 previous years. When you apply for the DTC, your medical practitioner will indicate the year your impairment began. If approved, the CRA will automatically reassess your past tax returns and send you a payment for any refund you are owed. You can also request these adjustments yourself through your CRA My Account or by mail.

Source: https://www.canada.ca/en/revenue-agency/services/tax/individuals/segments/tax-credits-deductions-persons-disabilities/disability-tax-credit.html