Mass. Gen. Laws ch. 190B § 3-1101
A compromise of any controversy as to admission to probate of any instrument offered for formal probate as the will of a decedent, as to the administration or distribution of an estate, or as to an accounting therefore, or as to any matter relating to said estate, or as to the construction of a will or trust created by a written instrument, or as to the fiduciary's power and authority thereunder, or as to any controversy growing out of said will or instrument that may arise between the fiduciary and any other person or the guardian or conservator of any person interested under said will or instrument or in said estate, or between claimants or the guardians or conservators of claimants to said estate, to which arbitration or compromise, in the form of an agreement in writing, such personal representative, guardian, conservator, receiver, commissioner or other fiduciary officer or trustee, and all other persons in being and of full age and not under guardianship, and the guardian or conservator, if any, of all other persons who claim a vested interest in said estate, whose interests will, in the opinion of the court, be affected by the proposed arbitration or compromise, shall be parties, if approved in a formal proceeding in the court for that purpose, is binding on all the parties thereto including those unborn, unascertained or who could not be located. An approved compromise is binding even though it may affect a trust or an inalienable interest. A compromise shall not impair the rights of creditors or of taxing authorities who are not parties to it.
Mass. Gen. Laws ch. 190B, § 3-1101