You do not need to be completely unable to walk, dress or perform another everyday activity to qualify for the Disability Tax Credit (DTC). But you must meet one of CRA's defined medical tests. Two important routes are a marked restriction in one category and the cumulative effect of significant restrictions in at least two categories.
A diagnosis is a medical label. The DTC instead looks at what the impairment actually prevents you from doing or makes take an inordinate amount of time, even with appropriate treatment and aids.
First: what does severe and prolonged mean?
The impairment must have lasted, or be expected to last, for a continuous period of at least 12 months. This is the prolonged requirement.
Severity is measured by its effect on specified daily-life activities. The recognized categories include walking, dressing, feeding, eliminating, speaking, hearing, vision and mental functions necessary for everyday life. Life-sustaining therapy is a separate eligibility route.
What is a marked restriction?
A marked restriction generally means you are unable to perform an activity, or take an inordinate amount of time to do it, all or substantially all of the time—generally 90% or more—even with appropriate therapy, devices and medication.
Example: Sarah can walk from her apartment to a nearby elevator, but doing so takes substantially longer than for a person of similar age without the impairment, even with a prescribed mobility aid. The practitioner must describe the actual degree, duration and frequency; this example alone does not guarantee approval.
What are cumulative significant limitations?
Some people have meaningful but individually less severe difficulties in two or more categories. If their combined effect is comparable to a marked restriction, they may qualify under the cumulative-effects route.
Example: Ryan has substantial limitations in both dressing and mental functions. Neither individual difficulty alone meets the marked-restriction threshold. The practitioner may describe how the combined effect is as severe as a marked restriction when the CRA criteria are satisfied.
What does the 90% rule refer to?
It concerns how consistently the restriction is present—not the percentage of hours someone is at work, nor a requirement that the person stay indoors all day. Describing one difficult day a month as a continuous restriction will not establish the test.
A medical practitioner should explain what happens on ordinary days, how long tasks take, what assistance is needed, and how the condition has changed over the years.
How should applicants prepare?
Use a short functional diary and share accurate examples with the practitioner completing T2201. CRA makes the final determination. If the condition instead involves qualifying life-sustaining therapy, evaluate that distinct route.
Sources and further reading
General educational content only. Verify current CRA and provincial guidance before acting.