It works like this:
Your home state of RI can tax ALL your income, regardless of where you earn it.
In addition, MA can tax you as a non-resident on any income you earn from work you actually (physically) perform within the state of MA. So you need to keep track of your days worked/dollars earned when you work in MA.
At tax time you'll be filing both a non-resident MA tax return and your home state RI return. RI will give you a credit for the tax you pay to MA on the income that is taxed by both states, so in effect you won't be double-taxed.
If you use TurboTax, be sure to complete the non-resident MA return before you do your home state RI return. The program will then calculate and apply the credit for you.
If you're working 2 days out of every 5 in MA, then 40% of your income may be taxable by MA. Since your employer is not withholding any MA taxes, you may wish to make estimated tax payment(s) to MA. You can find MA's rules about that here:
https://www.mass.gov/info-details/massachusetts-dor-estimated-tax-payments
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
