Massachusetts General Laws Part II. Real and Personal Property and Domestic Relations (Ch. 183-210) Ch. 190B, § 5-503

(a) If, following execution of a durable power of attorney, a court of the principal's domicile appoints a conservator, guardian of the estate, or other fiduciary charged with the management of all of the principal's property or all of his property except specified exclusions, the attorney in fact is accountable to the fiduciary as well as to the principal. The fiduciary has the same power to revoke or amend the power of attorney that the principal would have had if such principal were not disabled or incapacitated.

(b) A principal may nominate, by a durable power of attorney, the conservator, or guardian of the person for consideration by the court if protective proceedings for the principal's person or estate are thereafter commenced. A principal may in a nomination of a conservator or guardian request that sureties on any bond of a conservator or guardian be waived. The court shall make its appointment in accordance with the principal's most recent nomination in a durable power of attorney except for good cause or disqualification.