For taxpayers age 65 or older: Each taxpayer (you, and/or your spouse if filing jointly) who is age 65 or older at the end of the tax year may be entitled to a retirement credit of up to $450. This credit is limited by the total of your modified adjusted gross income, nontaxable interest income, and any additions to income reported on TC-40A, Part 1.

For taxpayers under age 65 who were born before January 1, 1953: Each taxpayer (you, and/or your spouse if filing jointly) who is under age 65 at the end of the tax year and was born before January 1, 1953, and received eligible retirement income, may qualify for a credit up to $288, but not more than 6% of the qualifying income. The credit is limited by the total of your modified adjusted gross income, nontaxable interest income, and any additions to income reported on TC-40A, Part 1. Form TC-40C is used to calculate the allowable credit.

Click here for information about which income does qualify for the credit and here for information about which income doesn't qualify.
NOTE: The Retirement Credit is phased out when modified adjusted gross income exceeds certain amounts based on filing status and shown on line 15 of TC-40C.