If it is the Oregon Statewide Transit tax, then just the tax part belongs in box 14 of your W-2 and you should not put anything for that particular tax in boxes 15-to-17. Only the one line for your normal state income and withholding taxes.
There is a selection for it in the box 14 "Tax Category" menu for box 14, "Oregon Statewide Transit Tax" ....so it is there,
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*
