With regard to your California tax obligation after you became a New York resident, the issue is when the RSU's were granted, not vested.
Once you became a New York resident, you would be taxed as a non-resident by CA only on RSU's that were granted when you were working in California.
Your CA taxable income from those RSU's would be according to the proportion: days worked in CA after the grant date divided by total days between grant date and vesting date.
To quote from the CA tax reference I cited in my previous post:
"on the vesting date:
- California will tax the wage income to the extent services were performed in California from the grant date to the vesting date."
Bottom line: any RSU that was granted after you ceased performing services in California would not result in any California-taxable income.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
