This would be the income you had that is being taxed by NY as a nonresident and by VT as a resident.
If you work in NY but live in VT, then you would need to file your NY return first. Once you do, you will look at IT-203 line 1 New York wages and enter them as the amount taxed in both NY and VT.
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"