My home is in MA. I worked on a temporary business assignment in California for about 2.5 years at a customer location. For 2020, I was finishing up my California business assignment and left CA in September. Then, I went on another business assignment (customer location) to Virginia for the remainder of the year. However, home is still MA to me. How should I file my state taxes? Should I file as a California resident since I was there for 2.5 years even though MA is still home to me? For the last part of 2020, should I file as a MA resident and VA non-resident? My work department is based out of MA the entire time. I went on travel to work with customers in CA and VA. My tax accountant filed me as a CA resident for 2019 taxes based on the CA physical presence of over 365 days. For 2020, should I file as part-year CA resident, part-year MA resident, and VA non-resident?
You have stated your home is in Massachusetts. Your absence from MA for work in other states is temporary and does not make you residents of those states as you intend to return home to MA. For 2020 you should file non-resident CA and non-resident VA and MA resident.
When you prepare multiple state return returns using TurboTax, prepare your non-resident state returns first. In your case, prepare your California, then Virginia and then Massachusetts last.