Thanks for this.
TurboTax would not let me enter a negative W code in box 12 so I reduced the W2 box 12 W amount by $4000 like you suggested. The Fed and State tax come to the same as when I did BillM223s fix so that's good.
Turbotax asks if I had uncommon situations on my W2, one of the options is Nonstandard W2 (handwritten, modified or altered). Should I select that or is this if the employer makes a change?
Trevor.
