In case anyone is curious or has a similar question, I did figure out how TaxAct is calculating expenses. If you only rented out your house for part of the year, they prorate all expenses. So in my case, I rented out the townhouse for 2/3 of 2015. I initially put the HOAs fees for May-December into the expenses in TaxAct. But they are prorating that number by 2/3. In order for the appropriate expense to be recorded, I needed to use the total amount of HOA fees for all of 2015, and then TaxAct multiplied that number 2/3 to get to the correct May-Dec amount.