Yes, add it as a positive number. In TurboTax, enter the description from your W-2's box 14 on the first field in the row. Enter the dollar amount as a positive number and select the correct tax category that goes with that description.
If none of the categories apply, scroll to the bottom of the list and choose Other (not classified). We'll figure out if it impacts your return or not. If we need more information, we'll ask you. Box 14