Your situation is not at all uncommon. I am assuming that you live in one state and work in another.
In most cases, the state in which you work will tax all of your earnings. Your state of residence will also tax all your earnings, but allow a tax credit for the taxes that you paid to the other state. If your employer withheld taxes for the state in which you work, everything should work out just about right. But, if your employer withheld taxes for your state of residence, you will have a large refund from that state, while owning a large tax bill to your work state.
There are several scenarios, which may even reverse the outcome, depending on reciprocity agreements between many, but not all, neighboring states.
