The Disability Tax Credit is a non-refundable tax credit for individuals with disabilities or their eligible caregivers, reducing income tax owed.  For children under 18, a supplement amount is also included.  This tax credit is intended to reduce the burden of disability-associated costs that average taxpayers do not face.

Who is eligible to claim this tax credit?
Eligibility is determined based on a completed form T2201, which must be completed by a medical practitioner, certifying that an individual has a severe and prolonged impairment, with significant impact on their day-to-day life.  

Who can provide medical certification for Form T2201?
The following chart, taken from the CRA website, denotes what professionals can certify specific areas of impairment:

Medical practitioner:can certify:
Medical doctorall sections
Nurse practitionerall sections
Occupational therapistwalking, feeding, dressing, and the cumulative effect for these activities
Psychologistmental functions necessary for everyday life
Speech-language pathologistspeaking

What disabilities are generally approved for the Disability Tax Credit?  
Approval is based on a variety of criteria, especially focused on the impact the disability has on one’s day-to-day life.  The self-administered eligibility quiz (try it here) may help you determine the likelihood of approval.  Specific eligibility criteria is closely defined here.

Approved disabilities must persist or be reasonably expected to persist for 12 months or more.  They must be present all or substantially all of the time (at least 90% of the time).

The person must meet one of the following criteria:
-is blind
-is markedly restricted in at least one of the basic activities of daily living
-is significantly restricted in two or more or the basic activities of daily living (can include a vision impairment)
-needs life-sustaining therapy, 14 hours or more per week

CRA Website

Approval for the DTC is an important step to accessing other government financial programs, such as the Registered Disability Savings Plan, the Working Income Tax Benefit and the Child Disability Benefit.