Mass. Gen. Laws ch. 171 § 21
The treasurer and all other officers and employees of a credit union having access to its cash or negotiable securities shall give bond to the credit union at its expense in such amounts and with such surety or sureties and conditions as the commissioner may prescribe. The directors may require bonds of such other officers, employees or agents as they deem advisable. The persons required to give bond may be included in one or more blanket or schedule bonds; provided, however, that bonds upon which changes are made are approved by the commissioner as to the amounts and the conditions thereof and as to the sureties thereon. Each credit union shall file with the commissioner on a form prescribed by him a certificate from the insurer indicating compliance with all requirements prescribed by the commissioner. The commissioner may prescribe the manner of custody and safekeeping of such bonds by the credit union.
Subject to the approval of the commissioner of insurance as to the form and conditions thereof, a schedule bond may be issued to an association of credit unions covering the officers and employees of the credit unions which are members of such association, notwithstanding that chapter one hundred and seventy-five does not expressly authorize the issuance of such a schedule bond.
Mass. Gen. Laws ch. 171, § 21