I have income in two states. TurboTax indicates that they can handle the situation. However, my Massachusetts form continues to tax my Virginia income (involving a capital gain) even after I select the option to exclude the capital gain from my Massachusetts return. I was able to manually fix the problem by changing the amount of tax paid to Virginia on the Massachusetts form, but it seems that this should happen automatically as promised.
Were you an MA resident for all of 2019? If so, you would not exclude your taxable VA capital gain from your MA return. Your resident state can tax all your income, regardless of where earned.
You can take a credit on your home state return for taxes paid to a non-resident state on income that is taxed by both states, so you won't be double-taxed.
In TurboTax, complete the non-resident state return before the home state return, so that the credit flows properly.
this answer makes sense. I filled out the resident state form first and then the non-resident state form. It would have been helpful for TurboTax to suggest starting with the non-resident state. Looks like Massachusetts will tax the capital gain and I have to manually enter the amount to be credited (which I did).