I am not a resident of MA, but I have to file a non-resident tax form there for my MA source income.
I have capital gains reported on Federal form 6781 which were NOT earned in MA.
These are reported on Federal Sch D Part 1 line 4 (short term) and Sch D Part II Line 11 (long term)
Walking through the MA state interview, there is never any option to mark these 6781 derived Federal capital gains as NON_MA_SOURCE. So, they are taxed on the MA non-resident state return as taxable income.
Turbotax: How do I mark these entries, both short and long term cap gains, from form 6781 as NON-MA in my state return???
