I am a hybrid worker but my company is only taking taxes from my home address (RI). I split my time 40% (MA) & 60% (RI). How should I be taxed?

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

Note that when using turbotax, you must manually allocate your income, the program can't guess for you.  Also, MA can only tax "MA-source income".  That includes income you earn from working while physically located in the state, and can also include lottery prizes or income from MA real estate (selling or renting).  MA source income does not include investment income (interest, dividends, capital gains), lottery prizes from other states, or a side gig that is not performed in MA, even if you work in MA part of the year.  So be careful when allocating your income, MA may get 40% of your wages but they get 0% of your investment income if your permanent residence is in Maine.

Also, track your days actually worked in MA, so you report the correct percentage (if you don't always split your time 2/3).