Infirm is a term that can mean “of poor vitality,” or not physically or mentally strong, especially because of illness. In Canada, there is a special individual tax credit a person can use if he or she has infirm dependants. The infirm dependant credit can be claimed for a relative who is 18 years old or older by the end of the tax year, provided he or she is dependent on you because of physical or mental illness.
The disability does not need to be so severe that the dependant qualifies for the disability tax credit. For tax year 2015, the credit amount is $6,700. This amount is reduced dollar-for-dollar for any amount in which the dependant’s income exceeds $6,720.