You will prepare and file a part-year AZ tax return for the time that you lived and worked in AZ. WA has no state income tax so you will not file a WA return.
As for the employer -- that is a conversation to have with HR or the payroll office to have them stop withholding AZ tax going forward.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
