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There is no ADHD tax credit as such. What people mean is the disability tax credit, and the CRA decides it by how your condition limits daily life, not by the diagnosis. For the 2025 return the federal amount was $10,138, worth up to $1,470.01 in tax for an adult.
Does ADHD qualify for the disability tax credit?
Sometimes. The CRA doesn’t hand out approvals by diagnosis. Its mental functions page says eligibility rests on the effects of an impairment, “not a diagnosis or the presence of a medical condition”. ADHD isn’t named on that page, and neither is any other condition. So anyone telling you ADHD is automatically covered, or automatically refused, is guessing.
The page lists ten mental functions used in everyday life. Attention, concentration, goal-setting, judgment, memory and regulating behaviour and emotions are among them. You need a marked restriction in one or more, which means the person can’t do it, or needs at least three times as long as others, all or almost all of the time (generally 90% or more). It also has to last, or be expected to last, at least 12 months.
Sound strict? It is.
A hard year, or a child who struggles at school and at home, doesn’t meet the test by itself. The practitioner has to describe a restriction that is there almost all the time and has lasted a year or more, and the CRA weighs that description against its own criteria.
Who can fill in the medical part?
For mental functions, the CRA names three kinds of practitioner: a medical doctor, a nurse practitioner or a psychologist. If your child’s ADHD is followed by a paediatrician or a family doctor, that person can usually be the one. Someone who only sees you for therapy may not be on that list, so ask before you book the appointment.
It helps to bring the practitioner specifics. Not “Sam can’t focus”, but “Sam needs a parent to restart each step of getting dressed, every morning, and has for two years.” The form asks about effects, so examples with time frames carry more weight than labels.
What is the credit worth?
The credit is the disability amount times the lowest federal rate, which was 14.5% for 2025. Children get a supplement on top.
| 2025 return | Amount | Federal credit |
|---|---|---|
| Adult | $10,138 | $1,470.01 |
| Under 18 at the end of the year | $10,138 plus $5,914 supplement, $16,052 in all | $2,327.54 |
The credit only lowers tax you’d otherwise pay. If you owe nothing, it doesn’t produce a refund by itself, though you can move it to someone else, as the next section explains. The under-18 supplement can shrink when child care or attendant care costs are claimed for the same person. Your province adds its own credit on top, and the disability tax credit calculator shows a 2026 provincial figure.
How do you apply, and can it go back in time?
You apply on form T2201, the Disability Tax Credit Certificate. You complete one part and a medical practitioner completes the other, since the CRA relies on what they report. Only approved people can claim.
Once approved, you enter the amount on line 31600. If you were eligible in earlier years and never claimed, the CRA allows you to go back up to 10 years. That’s where the money is.
Take an adult approved for every year since 2021 with enough tax paid each year. The federal credits add up to $6,994.81 over 2021 to 2025. For a child under 18 throughout, the total is $11,075.09. We ran both through our engine, and each year’s credit hinges on how much tax was actually paid that year, so a low earner will get less.
What if the person doesn’t pay enough tax? Then some or all of the amount can be transferred to a supporting family member, such as a parent or spouse, who provides basic necessities (food, shelter or clothing). The tax credits calculator shows the other federal credits that might sit alongside it.
What else opens up with an approval?
Approval matters beyond the credit. The registered disability savings plan is open to people approved for the DTC. And the Canada Disability Benefit needs DTC approval, plus an age between 18 and 64 and a filed return for 2024.
Medical expense claims are a separate matter. We haven’t confirmed which ADHD related costs count, so we won’t list any. Check the CRA’s medical expenses page before you claim anything.
Mistakes that cost families money
Waiting is the big one. Every year you don’t claim is a year you might lose after the 10 year limit.
Another is assuming the form is a formality. The practitioner must describe the restriction in real terms, and a diagnosis letter alone doesn’t do that.
A refusal doesn’t always end things, either. But we didn’t confirm the appeal steps, so use the CRA’s own pages to see what your options are. Once the money arrives, put it to work with the tax refund calculator, which shows what a refund does to your year.
Where we got these figures
Eligibility wording comes from the CRA‘s disability tax credit pages, including its mental functions eligibility page. The 2025 amounts come from the CRA’s claiming page, and the credit values are our own arithmetic at the 14.5% lowest federal rate. We used 2025 because it is the latest return year whose amounts we confirmed on a CRA page. This site isn’t connected to the CRA or any government.
Frequently asked questions
Is there a tax credit just for ADHD?
No. The credit that applies is the disability tax credit, which the CRA decides by the effects of the impairment, not by diagnosis.
How much is the disability tax credit for 2025?
The amount is $10,138, worth up to $1,470.01 for an adult at the 14.5% lowest federal rate. A child under 18 gets a supplement, for $16,052 in all.
Can I claim it for past years?
Yes, up to 10 years back if you were eligible, by asking the CRA to adjust earlier returns.
Who fills out form T2201?
You or your representative complete one part, and a medical practitioner completes the medical part.
Can a parent claim the credit for a child?
The credit can be transferred to a supporting family member, if the approved person doesn't need all of it.
- Canadian tax credits and government benefits explained
The difference between tax credits and benefits in Canada, how they're worked out from your return, and the calculators for the ones people claim most