I lived in California for most of 2019, where I worked for a California-based company. Effective December 23, 2019, I transferred to a New York-based group within the same company. From December 23 to December 31, I reported organizationally to the New York-based group, but I actually took time off (vacation plus holidays) the entire period. I did not begin living in New York until January 1, 2020, and I did not begin working in my employer's New York office until January 2, 2020.
I received one Form W-2 from my employer for 2019. Box 15 lists both CA and NY and Box 16 lists the same total amount of "State wages" for both states. (The Employer's state ID No. is different for CA and NY.) Obviously, I need to allocate the majority of my wages for the year to California and some smaller percentage to New York, e.g., based on 356 days "living and working" in California and 9 days "reporting to a group" in New York.
I plan to file a California part-year resident return for the period January 1 through December 22, 2019, but I'm not sure what to do for New York. Should I file a New York nonresident return for the period from December 23 through 31, since I didn't live in New York in 2019? Or should I file a New York part-year resident return for the period, even though I didn't live (or actually work) in New York in 2019?
