Quick Answer
For the Disability Tax Credit, medical practitioners help by certifying Form T2201 Part B. CRA is looking for clear functional evidence: what the patient cannot do, what takes an inordinate amount of time, how often the restriction occurs, how long it has lasted or is expected to last, and what treatment or assistive devices are already being used.
Why Medical Practitioner Certification Matters
The Disability Tax Credit is decided by the Canada Revenue Agency, but CRA relies heavily on the medical information certified in Form T2201. The patient completes Part A. The medical practitioner completes Part B and certifies how the impairment affects basic activities of daily living or life-sustaining therapy.
A strong Part B does not guarantee approval. It does, however, give CRA the functional detail needed to decide the application fairly. Many weak applications fail because the form lists diagnoses without explaining frequency, duration, treatment, support needs, or the real effect on daily life.
What CRA Looks For in Part B
CRA's decision is based on the effects of an impairment, not the diagnosis alone. A patient may have a serious medical condition and still not meet the DTC test if the form does not show a severe and prolonged functional restriction. In most marked-restriction cases, Part B should answer five practical questions:
- Function: which basic activity of daily living is restricted
- Severity: whether the patient is unable to perform the activity, or takes an inordinate amount of time
- Frequency: whether the restriction is present all or substantially all of the time, generally interpreted as 90% or more
- Duration: whether the impairment has lasted, or is expected to last, at least 12 consecutive months
- Treatment context: how the patient functions even with appropriate therapy, medication, devices, or support
Who Can Certify Each DTC Category
Medical doctors and nurse practitioners can certify all DTC categories. Other regulated practitioners can certify specific categories within their professional scope. When the patient's impairment crosses categories, use the practitioner who can best describe the dominant restriction, or coordinate information from more than one clinician.
| DTC category | Practitioners who commonly certify | Documentation focus |
|---|---|---|
| Vision | Medical doctor, optometrist, nurse practitioner | Visual acuity, field of vision, functional effect after correction |
| Hearing | Medical doctor, audiologist, nurse practitioner | Audiogram, speech discrimination, communication limits with devices |
| Speaking | Medical doctor, speech-language pathologist, nurse practitioner | Expressive communication, intelligibility, frequency of inability to speak |
| Walking | Medical doctor, physiotherapist, occupational therapist, nurse practitioner | Distance, speed, rests, pain, fatigue, falls, aids, terrain limits |
| Feeding or dressing | Medical doctor, occupational therapist, nurse practitioner | Setup, time, safety, adaptive devices, assistance required |
| Eliminating | Medical doctor, nurse practitioner | Frequency, urgency, incontinence, ostomy care, treatment response |
| Mental functions | Medical doctor, psychologist, nurse practitioner | Adaptive functioning, memory, judgment, problem-solving, behaviour, safety |
| Life-sustaining therapy | Medical doctor, nurse practitioner | Therapy supports a vital function and meets the weekly time threshold |
Part B Writing Principles
Part B should be specific enough that an assessor can understand the patient's functioning without knowing the patient personally. It helps to avoid broad phrases such as "severe impairment" unless they are followed by concrete examples.
Use Functional Language
Write about daily function, not only diagnosis. For example, "takes 45 minutes to dress because of hand pain and shoulder limitation" is stronger than "has rheumatoid arthritis." "Needs prompting for medication, hygiene, meals, and safe community navigation most days" is stronger than "has depression and anxiety."
State Frequency Clearly
CRA must understand whether the restriction exists all or substantially all of the time. When appropriate, use a clear phrase such as "this restriction is present at least 90% of days" or "the patient requires supervision all or substantially all of the time."
Explain Treatment and Devices
Describe functioning after appropriate medication, therapy, devices, or aids are used. If the patient uses a cane, walker, hearing aids, insulin therapy, medication management support, or behavioural strategies, note the remaining restrictions despite those supports.
Connect the Start Date to Medical Records
If the patient requests prior years, identify when the marked or cumulative restriction likely began and what records support that date. If you can only certify from the date you began treating the patient, say that plainly and consider whether prior records from another practitioner are available.
Examples of Stronger Part B Detail
Walking
Less useful: "Patient has osteoarthritis and difficulty walking."
More useful: "Patient walks approximately 30 metres on level ground before stopping because of pain and shortness of breath. Uses a cane indoors and a walker outdoors. Requires rest after stairs. This pattern has been present for more than two years despite medication and physiotherapy."
Mental Functions
Less useful: "Patient has major depression and memory problems."
More useful: "Patient requires spouse supervision for medication, appointments, bills, meal planning, and safety decisions. Misses or repeats tasks without prompting. Restriction affects adaptive functioning, memory, judgment, and goal-setting on most days despite treatment."
Eliminating
Less useful: "Patient has Crohn's disease with diarrhea."
More useful: "Patient has 8 to 12 bowel movements daily with urgency and unpredictable flares. Needs immediate bathroom access, has monthly incontinence episodes, and cannot reliably leave home for long appointments without interruption despite specialist treatment."
Cumulative Effects: When No Single Category Is Enough
A patient may qualify when two or more significant restrictions, taken together, are equivalent to one marked restriction. This is especially important for patients with complex chronic illness, fatigue, pain, cognitive impairment, or multiple moderate impairments that interact throughout the day.
For cumulative effects, Part B should explain how the restrictions combine in real life. For example, walking pain, dressing difficulty, and medication side effects may together make morning self-care take several times longer. Mental functions and physical fatigue may combine so that a patient cannot plan, start, and complete basic daily tasks without repeated support.
Life-Sustaining Therapy Notes
Life-sustaining therapy can qualify when therapy is needed to support a vital function and meets CRA's time and frequency rules. For these applications, clearly identify the therapy, the weekly time spent, what activities are medically required, and what cannot be counted. The strongest forms separate medical therapy time from general lifestyle management, travel, or optional activities.
How to Help a Patient Prepare
Patients often arrive with diagnosis labels but not functional examples. Before completing Part B, it can help to ask the patient or caregiver for a short daily-life summary. Useful prompts include:
- What activity takes three times longer than it would for someone of similar age without the impairment
- How often the restriction occurs in a normal week
- What help, prompting, supervision, device, or therapy is required
- What happens on bad days, and how often bad days occur
- What treatment has already been tried and what limitations remain
- When the restriction began and whether earlier records support that date
Common Application Mistakes to Avoid
- Listing only the diagnosis without describing functional impact
- Failing to address the "all or substantially all of the time" threshold
- Using vague terms such as "limited," "disabled," or "severe" without examples
- Not explaining functioning after treatment, medication, or assistive devices
- Leaving cumulative effects blank when multiple significant restrictions interact
- Certifying retroactive years without explaining the medical basis for the start date
- Not responding fully to CRA follow-up questionnaires
If CRA Sends a Follow-Up Questionnaire
A follow-up questionnaire does not always mean the application will be denied. It often means CRA needs clearer examples, dates, treatment details, or confirmation that the restriction is severe and prolonged. Treat the questionnaire as a chance to close the evidence gap. Use the same principles: functional examples, frequency, duration, treatment context, and records that support the answer.
Medical Practitioner DTC Guide FAQ
Yes. Nurse practitioners can certify all DTC categories. Medical doctors can also certify all categories. Other practitioners can certify the categories that match their scope.
Both can help, but functional examples matter most. CRA evaluates how the impairment restricts basic activities of daily living, not diagnosis alone.
No. A practitioner certifies medical and functional information. CRA decides whether the patient meets the Disability Tax Credit eligibility criteria.
Respond with specific examples, dates, treatment details, and confirmation of frequency and duration. The response should address the exact gap CRA identified.