Your resident state of MA can tax ALL your income, regardless of where you earned it.
You non-resident state of NY can tax only the portion of your income that you earned in NY.
Therefore your NY income is taxable by both states.
BUT you'll be able to take a credit on your MA return for the tax you pay to NY on the portion of your income that is taxed by both states, so you won't actually be double-taxed.
In the personal info section of TT, put your state of residence as MA, and indicate that you had other state income from NY. This will prompt the program to generate the correct state tax forms.
Be sure to complete your non-resident NY return before you do your home state MA return, so that the credit flows properly.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
