If I work in MA as an independent contractor but live in NY full-time with my business address in NY, do I need to file a return in MA or simply with NY and Feds?

[Opus 17 · Accepted solution]

Both states.  If you live in NY, you fill out an NY tax return to report all your world-wide income.  Then, if you have income in another state, you fill out a non-resident income tax return for that state to pay state tax on in-state income tax only.  To prevent double taxation, most states allow a deduction for out of state taxes paid.  Using Turbotax, you will prepare your Mass non-resident return first and your NY resident return last.  Turbotax will apply a credit for Mass income tax paid to your NY tax return.