Mass. Gen. Laws ch. 114 § 3A
No cemetery corporation created by special charter or organized under the provisions of section one shall take over ownership of an unoccupied grave unless a minimum of seventy-five years has elapsed after issuance of a license for the grave by the cemetery corporation or its predecessor in interest; and the cemetery corporation 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 cemetery corporation shall pay the fair value of the license at the time of its taking to the owner.
No cemetery corporation created by special charter or organized under the provisions of section one 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 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 where the cemetery is located 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, § 3A