Yes, the interest from Fidelity qualifies for the MA interest exemption. According to the Mass Dept of Revenue, if a bank has a branch location in the state of Massachusetts then it is considered a Massachusetts bank for Massachusetts income tax purposes.

You're allowed an exemption of $200 (if married filing jointly) or $100 (for all other filing statuses) for reporting Massachusetts bank interest. Massachusetts bank interest includes the total amount of interest received or credited to deposit accounts (term and time deposits, including certificates of deposit, savings accounts, savings shares, and NOW accounts.)

To report the exemption on your MA tax return:

1. Enter the exemption amount on either Form 1 (Line 5b) or Form 1-NR/PY (Line 7b). If married filing jointly, enter $200. Otherwise, enter $100.

Thank you for the answer ... very helpful. The Fidelity interest is from bonds I bought through Fidelity, and was reported in Fidelity 1090-INT. Does this still count as "MA interest"? Or only savings/CDs/etc. can count as "interest"?

Yes if it was reported on Form 1099-INT from Fidelity it is "MA Interest"