Mass. Gen. Laws ch. 114 § 10A
No municipality shall take over the ownership of an unoccupied grave unless a minimum of seventy-five years has elapsed after issuance of a license for the grave by the municipality or its predecessor in interest; and the municipality cannot locate the license holder or the holder's successor in interest after making a diligent search. If ownership of the license is ascertained after such a taking occurs, then the municipality shall pay the fair value of the license at the time of its taking to the owner.
No municipality shall reuse an occupied grave except: upon the request and with the consent of a relative or descendant of the decedent occupying the grave, providing that no other descendant objects; to provide for the burial of a relative or descendant of the decedent occupying the grave; and if the remains of the decedent occupying the grave will remain in the grave. The municipality shall determine, by by-law or ordinance, the method to be used in reusing such occupied graves and may reasonably limit the circumstances under which such reuse can occur.
Mass. Gen. Laws ch. 114, § 10A