If you let the program do the splits for you, then you just enter the total amount. Otherwise, if you elected to do the splits manually yourself, enter 1/12 of the mortgage interest on the SCH E for each month the property was classified as a rental. Then enter 1/12 of the mortgage interest on the SCH A for each month it was your residence. You'll find the below information helpful too, if 2018 was your first year leasing the property out.
