Tax Credit for the Elderly and Disabled - Taxpayers age 65 or older or those under 65 who are retired with permanent and total disability are entitled to claim a credit to decrease the amount of their tax liability. It's designed primarily to benefit those individuals who receive small amounts of retirement INCOME. Every taxpayer is allocated an initial base amount based on her or his filing status determining the credit. Base amount is then decreased by the amount of non-taxable income or is phased out for taxpayers whose ADJUSTED GROSS INCOME exceeds certain levels.