When you prepare your tax returns you need to use the mailing address where you want the IRS or state to mail you a letter or a check. You have not mentioned what state you moved from or where you are now. If you worked in the new state, then you will need to file a part-year return for that state, and a part-year return for your old state if you worked in the old state before the move. However, it would be helpful to us to know what states are involved, since some states have reciprocal agreements with each other.