Thanks for the detailed response!
One more question: how do I correct the capital loss carryover in my current (2016) return?
I found the error in my 2015 return, which I will amend by sending in a 1040X on paper. According to the amended return, my capital loss carryover for 2016 will be reduced. However, I started on my 2016 taxes already, using the original 2015 return, and as a result, the carryover amount is incorrect now in my 2016 return (I haven't filed it yet). How do I fix the carryover amount, so that it reflects the correct, amended amount?
