Wisconsin Addition or Subtraction From Income - Differences in Federal and Wisconsin Basis of Partnership Interest
An addition or subtraction may be necessary if you sold your interest in a partnership and any increases or decreases were made to the federal basis of your partnership interest in taxable years prior to 1975, which resulted from partnership business or property located outside Wisconsin. (Prior to 1975, Wisconsin did not tax income from business or property located outside Wisconsin.)
Enter the additions in the Addition to Income section and subtractions in the Subtraction from Income section.
For further information, please see WI state instructions.