Massachusetts General Laws Part II. Real and Personal Property and Domestic Relations (Ch. 183-210) Ch. 190B, § 5-430

(a) Any person indebted to a protected person or having possession of property or of an instrument evidencing a debt, stock, or chose in action belonging to a protected person may pay or deliver it to a conservator, guardian of the estate, or other like fiduciary appointed by a court of the state of residence of the protected person upon being presented with proof of appointment and an affidavit made by or on behalf of the fiduciary stating:

(b) If the person to whom the affidavit is presented is not aware of any protective proceeding pending in the commonwealth, payment or delivery in response to the demand and affidavit discharges the debtor or possessor.