TurboTax will create the Schedule NRH in the Maine state tax section. You will need to indicate that you are filing the Maine return as separate.
If your filing status on your federal income tax return is married filing jointly, you may elect to file as a single individual on the Maine return. Schedule NRH is designed to separate joint income between spouses and, if the filer is a nonresident or partyear resident, between Maine source income and non-Maine source income.