Quick Answer
Your doctor does not write a separate letter, they complete Part B of Form T2201. The most important thing is to share accurate functional examples so your practitioner can describe limitations clearly ("patient takes 45-60 minutes to dress due to joint pain") rather than diagnostic descriptions ("severe rheumatoid arthritis"). CRA evaluates functional impact, not diagnosis severity.
There Is No Separate Doctor Letter
One of the most common misconceptions about the Disability Tax Credit is that you need a doctor's letter. You do not. The CRA's process uses Form T2201, the Disability Tax Credit Certificate. Part A is completed by you; Part B is completed and signed by a medical practitioner. Part B is the equivalent of the doctor letter, the entire medical certification happens within the form's structured sections. For certifier roles by category, see the medical practitioner DTC guide.
What CRA Actually Looks For
CRA assessors read Part B looking for two things:
- Severity: does the impairment markedly restrict a basic activity of daily living The standard is whether the activity cannot be performed at all, or takes 3+ times longer than normal, even with appropriate therapy and aids
- Duration: has the impairment lasted, or is expected to last, at least 12 consecutive months
The strongest Part B answers describe specific functional impact in specific situations, not vague clinical impressions.
Strong vs Weak Functional Language
Walking Category Example
- Strong: "Patient can walk approximately 30 metres on a level surface before stopping due to severe knee pain and breathlessness. Uses a cane indoors and a four-wheel walker outdoors. Cannot climb more than 2 stairs without stopping. This pattern has been consistent for 4 years."
- Weak: "Patient has severe osteoarthritis and ambulates with difficulty."
Mental Functions Example
- Strong: "Patient is unable to manage own finances, plan basic meals, or track medication schedules without family supervision. Memory deficits documented on MoCA score of 14/30. Adaptive functioning markedly impaired at least 90% of days. This has been the case since 2022, despite trials of donepezil and rivastigmine."
- Weak: "Patient has Alzheimer's disease with progressive cognitive decline."
Eliminating (Crohn's) Example
- Strong: "Patient experiences 8-12 bowel movements daily with significant urgency. Has had 4 episodes of incontinence per month over the past year. Cannot leave home for more than 2 hours without bathroom access. Active despite biologic therapy (Stelara) and multiple prior immunomodulators."
- Weak: "Patient has active Crohn's disease with chronic diarrhea."
How to Prepare for Your Practitioner Discussion
Some practitioners complete few T2201 forms per year and may benefit from clear, accurate examples of daily functional impact. Prepare for the discussion by:
- Prepare a functional summary in writing before the appointment, describing your daily limitations with concrete examples (time required, distance walked, frequency of episodes, etc.)
- Bring relevant documentation to the appointment: imaging, specialist letters, functional assessments, prior denials with reasons
- Ask the doctor to address the 90% threshold explicitly, stating that the restriction is present "all or substantially all of the time" or "approximately 90% of the time"
- Request specific functional language by topic area, you can share strong examples like those above
- Request that the doctor describe your functioning with appropriate treatment, this is what CRA assesses
Remember: do not script the answers. The certification must reflect your doctor's genuine clinical judgment. Coaching means providing accurate functional information they can use, not asking them to write something untrue.
If Your Doctor Charges a Fee
OHIP (Ontario), MSP (BC), and other provincial plans typically do not cover T2201 completion. Many doctors charge $50-$300 for completing the form. The fee is not refundable by CRA but may be a deductible medical expense. Some doctors waive the fee for low-income patients, ask.
Which Practitioner to Use
Different impairment categories accept different practitioner types:
- Vision: medical doctor or optometrist
- Speaking: medical doctor or speech-language pathologist
- Hearing: medical doctor or audiologist
- Walking: medical doctor, physiotherapist, occupational therapist, or nurse practitioner
- Eliminating: medical doctor or nurse practitioner
- Feeding or dressing: medical doctor, occupational therapist, or nurse practitioner
- Mental functions: medical doctor, psychologist, or nurse practitioner
- Life-sustaining therapy: medical doctor or nurse practitioner
For complex cases, a specialist (psychiatrist, rheumatologist, neurologist, gastroenterologist) provides stronger documentation than a family doctor alone.
Frequently Asked Questions
Family doctors can complete the T2201 for most categories. For complex or specialised cases (mental health, mobility, vision), specialist documentation can help describe functional limitations clearly when the case is complex.
Find another practitioner who knows your case. Many provinces have DTC-experienced doctors and nurse practitioners. For mental functions, a psychologist can certify. For walking or dressing, an OT or physiotherapist can certify.
Yes. CRA may contact the certifying practitioner directly for clarification. Authorisation is granted in Part A of the form. This is one reason why specific, accurate functional descriptions matter.
Optional but helpful for complex cases. Specialist letters, imaging reports, neuropsychological assessments, and functional capacity evaluations can support the Part B certification. CRA does not require these but reviews them if submitted.