I live in NJ, but worked in PA for most of 2016. I want to confirm whether I am required or not to file a PA tax return in addition to my NJ return.

[TomD8 · Accepted solution]

NJ and PA have tax reciprocity.  If you're an NJ resident, your W-2 wages earned in PA are not subject to PA income tax, and you do not have to file a PA return.  (Your wages are fully taxable by NJ.)  Note that tax reciprocity applies only to W-2 wages, not to other types of income.