You can qualify for the senior tax credit ("credit for the elderly or the disabled") If you are 65 or older by January 1 of the following year, you've retired on disability before the last day of the tax year and were permanently and totally disabled when you retired, you're under age 65 at the last day of the tax year but retired on permanent and total disability, or you've received taxable disability income and have not yet reached mandatory retirement age as of January 1 of the new tax year