Massachusetts General Laws Part II. Real and Personal Property and Domestic Relations (Ch. 183-210) Ch. 190B, § 3-604

(a) If a bond is required and the provisions of the will or order do not specify the amount, unless stated in the petition, the person qualifying shall file a statement under oath with the court indicating the best estimate of the value of the personal estate of the decedent and shall file a bond with the court in an amount equal to the estimate. The court may permit the amount of the bond to be reduced by the value of assets of the estate deposited with a domestic financial institution in a manner that prevents their unauthorized disposition. On petition of the personal representative or another interested person the court may increase or reduce the amount of the bond, release the surety, or permit the substitution of another bond with the same or different surety.

(b) In this section, “financial institution” means an organization authorized to do business under state or federal laws relating to financial institutions, and includes a bank, trust company, savings bank, building and loan association, savings and loan company or association, credit union and any corporation authorized to do business as a banking company under chapter 172A.