Some states that have income tax have reciprocal agreements with other states. If there is a reciprocal agreement between the two states, and you are an employee who gets a W-2, you only have to file a tax return in the state that you live in, not the state that you work in. So to get an answer for your specific situation you have to tell us what state you live in, what state you work in, and whether you work as a W-2 employee. Also tell us if any of these facts changed during the year.
