Pa balance due is 1638. I never have paid state taxes in pa since retirement. Whats up with this?

[FaithY]

I suggest comparing your 2017 PA tax return to your 2016 PA tax return to see what the difference(s) is. Go line by line on the tax return, and when you find a difference between 2017 and 2016, you can investigate the difference to find out why you owe $1,638.