I was listed as an Oregon state resident for all of 2016, but all my military wages were earned out of state, and the only income I received while in state was unemployment, which form do I use, 40N or 40P?
As a resident of Oregon, you will use OR-40.
If you entered the military from OR, your state of legal residence (HOR) continues to be OR no matter where you are stationed. As a resident of OR you are subject to OR state income tax, must file a OR tax return, and pay OR taxes (when applicable).
Active-duty military are considered to live in their state HOR no matter where they are stationed. Their active-duty pay is considered to be earned in their state HOR.
When you complete the Personal Interview: