Explain how that happens.......not sure it's possible.
Special situations
1) Dependent College students are residents of their parent's state....even if they spend the whole year in a different state at college.....they are not considered a resident of that college state. SO Not tax residents of both states.
2) Military people may be posted out of their HOR/SLR for their entire career...but they are not considered residents/domiciled in any other state they are posted to, unless they take special legal actions to reset their state of legal residence (SLR). Even if they have bought a home in some other state they are posted to...that doesn't make them a "resident" for tax purposes.
3) Washington DC? There are some special resident rules for folks living/working there for support as political staff purposes...but I'm not conversant of what limits there might be.
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*
