It's a tough one, @spaithane It is the employee's responsibility to inform the employer about their state of residency. It sounds like your former employer didn't have updated information and continued to pay you as a CA resident. I can understand the employer not willing to correct the W-2s. Candidly, it's not an easy process.
I would suggest professional help in this case. You might want to find a local tax preparer or tax attorney who would convey the message to CA FTB. They may decide that filing CA Form 3525 may help.
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"
