I have the exact same situation, except my son is also renting out two-thirds of his home, so only one third of the mortgage interest is deductible on Schedule A. The other 2/3 is a business expense for his rental business. How does he enter that in Turbotax? (Just adjust the amount for line 8b, I assume?)
The question still applies though: How to get this entry on line 8b (i.e. no seller financed, no 1098 form).
