Mortgage
interest and property taxes are divided between personal (Schedule A, itemized
deductions) and rental use (Schedule E) , proportional to the number of days
used for each.
If for example, the home was your personal residence until June 30, 2016, and you converted the home to a rental property on July 1, 2016, you would divide the mortgage interest and property taxes "50-50" between home (Schedule A) and rental (Schedule E)