Mass. Gen. Laws ch. 190B § 3-502
A petition for supervised administration may be filed by any interested person or by a personal representative at any time or the prayer for supervised administration may be joined with a petition in a testacy or appointment proceeding. If the testacy of the decedent and the priority and qualification of any personal representative have not been adjudicated previously, the petition for supervised administration shall include the matters required of a petition in a formal testacy proceeding and the notice requirements and procedures applicable to a formal testacy proceeding apply. If not previously adjudicated, the court shall adjudicate the testacy of the decedent and questions relating to the priority and qualifications of the personal representative in any case involving a request for supervised administration, even though the request for supervised administration may be denied. After notice to interested persons, the court shall order supervised administration of a decedent's estate:(1) if the decedent's will directs supervised administration, it shall be ordered unless the court finds that circumstances bearing on the need for supervised administration have changed since the execution of the will and that there is no necessity for supervised administration; (2) if the decedent's will directs unsupervised administration, supervised administration shall be ordered only upon a finding that it is necessary for protection of persons interested in the estate; or (3) in other cases if the court finds that supervised administration is necessary under the circumstances.
Mass. Gen. Laws ch. 190B, § 3-502