What is the Disability Supports Deduction? Complete Canadian Guide (Line 21500)

What is the Disability Supports Deduction?

The Disability Supports Deduction is a federal tax deduction available to Canadians who have a physical or mental impairment and who paid for devices or services to help them participate in work, business, research, or education. It is claimed on line 21500 of your T1 income tax return using Form T929.

Unlike a tax credit, this is a true deduction — it reduces your taxable income directly, which means the benefit increases with your marginal rate. A person in the 33% federal bracket saves $33 for every $100 deducted, before provincial savings are added on top.

This deduction is one of the more underused benefits in the Canadian tax code, partly because it is often confused with the Disability Tax Credit (DTC). The two are separate programs. You do not need to qualify for the DTC to claim the Disability Supports Deduction.

Who can claim it?

You can claim the Disability Supports Deduction if:

1. You have an impairment in physical or mental functions, and
2. You paid for devices or services so that you could carry out at least one of these activities:
   • Be employed or carry on a business (alone or as an active partner)
   • Do research or similar work for which you received a grant
   • Attend a designated educational institution or secondary school while enrolled in an educational program

The impairment does not need to be certified or registered anywhere in advance. There is no requirement to hold a DTC certificate. What matters is that the expense was necessary because of the impairment and that it enabled you to work, do research, or study.

For a full breakdown of eligibility rules, see Who Qualifies for the Disability Supports Deduction in Canada?

What expenses are eligible?

The CRA maintains a list of eligible devices and services in Guide RC4064, Disability-Related Information. Common examples include:

• Attendant care (for work-related purposes)
• Braille note-takers, printers, and displays
• Sign-language interpretation
• Optical scanners, voice-activated software
• Hearing devices and bliss boards
• Talking textbooks
• Reading services for the visually impaired
• Note-taking services
• Job coaching

For the complete list with conditions, see Complete List of Eligible Disability Support Expenses in Canada.

How is the deduction calculated?

The calculation has two steps, carried out on Form T929.

Step 1 calculates your net disability supports expenses. You take the total of all eligible amounts paid, subtract any reimbursements or non-taxable assistance received, and arrive at your net figure.

Step 2 determines the ceiling on your deduction. If you only worked or ran a business, the ceiling is your earned income. If you also attended school, a school-attendance bonus — weeks enrolled multiplied by $375, capped at $15,000 — is added to raise that ceiling. Your actual deduction is whichever is lower: the net expenses from Step 1 or the ceiling from Step 2.

The T929 Disability Supports Deduction Calculator mirrors this form exactly and shows your result in seconds.

Deduction vs. credit — why it matters

The Disability Supports Deduction is a deduction, not a credit. This distinction is significant:

• A deduction reduces your taxable income. A $5,000 deduction for someone in the 33% federal bracket saves $1,650 in federal tax (plus provincial savings). The higher your income, the more you save.
• A non-refundable credit reduces the tax you owe. The basic disability amount credit, for example, is worth a fixed 15% federally regardless of your income level.

Because the deduction scales with income, it is most valuable for higher earners. For lower earners, the medical expense tax credit — which covers many of the same expenses — might produce a better outcome.

The cannot-double-claim rule

You cannot claim the same expense as both a disability supports deduction and a medical expense. This is one of the most important planning decisions when filing.

If an expense qualifies under both programs, you must choose which one to claim it under. In some cases, splitting expenses between the two programs (claiming part as a deduction and unrelated expenses as medical) gives the best overall result.

The Disability Supports Deduction vs. Medical Expense Tax Credit guide walks through exactly how to decide.

The student school-attendance bonus

One of the least-known features of this deduction is the bonus available to students. If you attended a designated educational institution or secondary school while enrolled in an educational program, you can add a school-attendance amount to your earned income ceiling.

The formula: number of weeks enrolled × $375, capped at $15,000.

This matters because many disabled students have low or no earned income. Without the bonus, their deduction ceiling would be near zero even if they paid significant disability-related expenses. The bonus effectively allows part of those expenses to be deducted based on school attendance rather than employment.

Read the full breakdown in The $375/Week Student Bonus in the Disability Supports Deduction.

What expenses cannot be claimed?

You cannot claim:

• Amounts reimbursed by insurance or any non-taxable payment
• Amounts already claimed as medical expenses on lines 33099 or 33199
• Expenses paid in a prior year (claims must match the year expenses were paid)
• Expenses not connected to work, business, research, or education

Unused amounts cannot be carried forward. If your net expenses exceed the income-based ceiling, the excess is simply lost.

Supporting documents

Do not attach Form T929 or receipts to your tax return. Keep them in case the CRA asks to see them later.

Receipts must show the name of the person or company paid. For attendant care payments made to an individual, the receipt must also include their Social Insurance Number.

How to use the calculator

The T929 Disability Supports Deduction Calculator handles both the standard path (work/business only) and the student path. Enter your expenses, reimbursements, earned income, and — if applicable — net income and weeks enrolled. The calculator outputs each line of the T929 form and estimates your tax savings at your combined marginal rate.

Step-by-step filing guide

For a complete walkthrough of how to fill in Form T929 and enter the result on your T1, see How to Complete Form T929: Step-by-Step Guide.

Disclaimer: This article is for general information purposes only. Tax rules change annually. Always verify with the CRA or a qualified Canadian tax professional before filing.