You must file a part-year resident tax return in both IL and IN.
In addition, you must file a non-resident OH return, on which you allocate zero income to OH. That's because IN and OH have tax reciprocity. Reciprocity means that the W2 income of IN residents who work in OH is not taxable by the state of Ohio; it is taxable only by their resident state of IN. Your OH employer should not have withheld OH taxes from your pay. Filing a non-resident OH return will result in those incorrectly withheld OH taxes being refunded to you. You will have to pay IN income tax on all your earnings as an IN resident.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
