Hi wdkuntz, 

Thanks for reaching out! 

To qualify for the Disability Tax Credit, you must have a serious and prolonged physical or mental impairment. Depending on the situation, you may be able to claim this credit for yourself, or on behalf of your dependent, spouse or common-law partner.

Variations of the eligibility criteria are vast but the following are a few things to take into consideration when trying to figure it out; you experience difficulty performing activities of daily living such as walking, feeding yourself, hearing, speaking, or other debilitating conditions that affect day-to-day living

To see if you are eligible, please check out this link: https://www.canada.ca/en/revenue-agency/services/tax/individuals/segments/tax-credits-deductions-per.... 

To learn more on how to apply, please see the following link: https://www.canada.ca/en/revenue-agency/services/tax/individuals/segments/tax-credits-deductions-per....

Hoping this information helps! 
Mohammed