If you intend to return to Pennsylvania, it may be your state of domicile; however, for state tax purposes you are now a resident of Washington DC.  You should file a Washington DC Resident (or part year resident) return for the time you lived in DC. 

Thank you!

If state of domicile is PA then you are a resident of PA and a non-resident of DC.

That's how I understand it .

That's how it was explained to me by a tax auditor in the Oregon Dept of Revenue.