Mass. Gen. Laws ch. 221 § 61
The court shall award reasonable compensation and allow actual expenses of travel in attending hearings, if said expenses be approved by the court as reasonable, to masters, and the same shall be paid by the commonwealth if they are appointed by the supreme judicial court, the superior court department or the probate and family court department. If they are appointed by any other department, the compensation awarded and expenses of travel allowed may be paid by either party and taxes in his bill or costs if he prevails; but the plaintiff shall be liable for such payment, and the court may make all orders and decrees, and issue process to enforce the same. No allowance for the expenses of travel shall be allowed by the court, unless the master shall file a true and correct account of such expenses, signed and sworn to by him.
Mass. Gen. Laws ch. 221, § 61