CRA Form T2201 for ADHD: Part A, Part B and 'Marked Restriction'

You have an ADHD diagnosis, you have heard the Disability Tax Credit exists, and someone has handed you a form with two parts and a great deal of small print. Form T2201, the Disability Tax Credit Certificate, is the only way in. A T2201 ADHD application lives or dies on one section of Part B, and most of the refusals people describe trace back to how that section was written, not to the diagnosis itself.

This guide walks through the form the way CRA reads it: what you complete, what your clinician completes, which mental functions CRA actually scores, and the difference between a marked restriction and a significant limitation. If you want the short version of what the credit is first, start with what the Disability Tax Credit is for ADHD.

Part A: what you fill in yourself, and the digital option

Part A is the applicant's section. It asks for the name, date of birth, social insurance number and address of the person with the impairment, and whether someone else (a spouse, a parent, another supporting relative) will claim the credit on their behalf. It also asks whether you want CRA to adjust previous years' returns automatically if you are approved. Tick yes; CRA can go back up to ten years.

There are two ways to complete it. The paper route: print the form, fill in Part A by hand, take the whole thing to your clinician for Part B, then mail it or upload it through My Account. The digital route: sign in to CRA My Account, open the Disability Tax Credit section and complete Part A online. CRA gives you a reference number. You pass it to your clinician, who completes Part B through their own secure portal. Nothing is printed, and you can see in My Account when it has been submitted.

• Use the digital route if you can.
• Screenshot the reference number and note the date you sent it.
• If a parent is claiming for a teen, Part A still names the teen as the person with the impairment, and the parent as the claimant.

Part B: who can certify ADHD and what they must write

Part B belongs to the medical practitioner. For the mental functions category, CRA accepts three kinds of certifier: a medical doctor, a nurse practitioner or a psychologist. Occupational therapists can sign other sections (walking, dressing, the cumulative-effect section) but not mental functions on their own. Social workers, psychotherapists and ADHD coaches cannot certify any part of the form.

What the certifier must document is effects, not diagnosis. The form asks them to describe how the impairment restricts you in everyday life, when the restriction began, and whether it is expected to last at least 12 continuous months. A line that reads 'Diagnosed with ADHD, combined presentation' gives CRA nothing it can score. A line that reads 'Needs prompting from another adult to start and finish routine tasks such as bills and medication on most days, even with treatment in place' is the kind of sentence that gets read.

Bring your assessment report to the appointment. A diagnosis letter on its own will not be accepted in place of Part B, but it gives the certifier concrete examples to draw on; here is how a diagnosis letter fits into a DTC application. Many clinicians charge a fee for completing the form, commonly somewhere between $50 and $200. That fee is itself an eligible medical expense on your tax return, so keep the receipt.

'Mental functions necessary for everyday life': the list CRA scores

Since the 2021 changes to the Income Tax Act, the form spells out the functions CRA considers rather than lumping them into three groups. The current list:

• Attention
• Concentration
• Memory
• Judgement
• Perception of reality
• Problem-solving
• Goal-setting
• Regulation of behaviour and emotions
• Verbal and non-verbal comprehension
• Adaptive functioning: the everyday skills of looking after yourself, managing money and getting along with other people

For ADHD, the functions that usually carry an application are attention, concentration, memory, goal-setting, regulation of behaviour and emotions, and adaptive functioning. The certifier does not need to say you are restricted in all of them. Under the current rules a marked restriction in one function can be enough, as can the combined effect of several.

What helps is specificity. For each function the certifier ticks, CRA wants an example from daily life, not from work or school alone: forgetting to eat until evening, missing medical appointments despite reminders, a utility cut off because the bill sat unopened, needing another person to run the household budget.

Marked restriction vs. significant limitation vs. cumulative effect

These three phrases decide the outcome, and each has a precise meaning.

Marked restriction. You are unable to perform the function, or it takes you an inordinate amount of time (CRA's working rule is roughly three times as long as a person without the impairment), all or substantially all of the time, which CRA reads as at least 90 per cent of the time. This has to be true even with medication, therapy and devices in place, and it must have lasted, or be expected to last, 12 continuous months. One marked restriction in mental functions qualifies on its own.

Significant limitation. A restriction that is real but falls short of marked in a single category. On its own it does not qualify.

Cumulative effect. Two or more significant limitations that, added together, are equivalent to one marked restriction. Mental functions can be one of those categories. So an adult whose attention and adaptive functioning are each significantly but not markedly limited may still qualify under the cumulative-effect section, if the certifier fills that section in. Many do not, because it sits apart from the rest and is easy to skip.

The honest consequence for ADHD: if treatment brings your day-to-day functioning close to typical, you may not meet the bar. CRA assesses function with treatment in place, not the untreated baseline.

Common reasons ADHD applications come back

• The certifier described the diagnosis and the symptoms rather than the effect on everyday life.
• Wording that is vague by design: 'some difficulty', 'struggles with', 'can be forgetful'. CRA cannot score an adverb.
• Every example is about work or university. The test is everyday life, so home, money, health and relationships need to be in there.
• The onset date is missing or set later than it should be. For ADHD the onset is usually childhood, and the date affects how many past years can be adjusted.
• The 12-month duration box is unchecked, or the certifier wrote that the restriction is episodic.
• The certifier is not an eligible profession for mental functions.
• CRA sent a clarification questionnaire to the clinician and it was never returned. Chase the clinic yourself; CRA denies the application if no answer arrives.
• Part A was unsigned, or the social insurance number was wrong.

If you are refused, you can ask CRA to review the decision with new or clearer information from the certifier, and you can file a formal objection within 90 days of the notice. A clearer Part B is often all that was missing.

What to do this week

1. Sign in to CRA My Account and complete Part A digitally. Write down the reference number.
2. Book an appointment with an eligible certifier (doctor, nurse practitioner or psychologist) and tell the receptionist it is for Form T2201 so enough time gets booked.
3. Before the appointment, write one page of everyday examples under each function that applies to you: attention, memory, goal-setting, regulation of emotions, adaptive functioning. Describe what happens with your current treatment, not before it.
4. Bring your assessment report, the page of examples, and a list of the supports you rely on (another person, alarms, a pill organiser, autopay).
5. After submission, set a calendar reminder for eight weeks out to check My Account, and a second one to chase the clinic if CRA writes to them for clarification.

Approval does more than lower one year's tax. It opens the Registered Disability Savings Plan, the Canada Disability Benefit and the disability supplement to the Canada Workers Benefit. The complete guide to the DTC for ADHD covers what the credit is worth and what it unlocks, and this post on your assessment report explains which parts of it your certifier will want to see.