The credit is based on your filing status, age, and income. If you are married and filing a joint return, it is also based on your spouse's age and income. You may be able to take this credit if either of the following applies.
1. You were age 65 or older at the end of 2019, or
2. You were under age 65 at the end of 2019 and you meet all of the following.
a. You were permanently and totally disabled on the date you retired. If you retired before 1977, you must have been permanently and totally disabled on January 1, 1976, or January 1, 1977.
b. You received taxable disability income for 2019. c. On January 1, 2019, you hadn't reached mandatory retirement age (the age when your employer's retirement program would have required you to retire).
For more information see IRS Instructions for Schedule R.