Schedule K-1 Box 13 Code T reports Domestic Production Activity. Enter the amount from 13T-1 in the box for that code. The next two screens will provide additional boxes for you to enter the remaining subcodes for Box 13T. Pay close attention to the row and column headings to be sure you enter the amounts from your K-1 into the corresponding boxes.
(See the attached screenshot below. Click to enlarge.)
Note: If you have any other details or another Code besides T regarding this question, please feel free to post them in the comment section.