Mass. Gen. Laws ch. 171, § 41A

No credit union shall assess any fee, charge or other assessment against any account, established for personal, family or household purposes, of a depositor or shareholder who, as the payee of a check, draft or money order, of which the payee is not also the maker, deposits the same therein and payment on any such instrument is refused by the depository institution upon which it is drawn because of insufficient funds or because the maker thereof did not have an account at such depository institution; provided, however, that a credit union may assess a reasonable fee, charge or assessment that represents its direct costs, as established annually by the commissioner of banks, incurred for processing such check, draft or money order.