Thanks for the info. I googled "5 states that tax remote workers" and nothing came up. What did come up was this...
https://tax.thomsonreuters.com/blog/state-by-state-reciprocity-agreements/
Looks like MA is not a state that has a reciprocity agreement with any of the 17 states that have reciprocity agreements. So, my guess is that I'll have to pay MA, NJ, and CA after all. Going to an accountant tomorrow to find out for sure. Lots of various suggestions/advice on this thread so I'm still unclear.
