Mass. Gen. Laws ch. 175 § 156
Any such company may appoint trustees, who are citizens or corporations of the United States and approved by the commissioner, to hold funds in trust for the benefit of its policyholders and creditors in the United States. Said trustees shall be named by the directors of the company, and a certified copy of the record of the appointment of such trustees and a duplicate original of the deed of trust on a form approved by him shall be filed with the commissioner, who may examine such trustees and the assets in trust and all books and papers relative thereto in the same manner as he may examine the officers, agents, assets and affairs of companies. The funds so held by such trustees, and all assets held by or for such company within the United States for the benefit of its policyholders and creditors in the United States, so far as the same are in securities, money or credits admissible as sound assets in the financial accounts of companies, shall, with its deposits made in accordance with the preceding section, constitute the assets of such company for the purpose of making its annual statements to the commissioner. Such company shall file with the annual statement required by section twenty-five a statement of the trustees executed as prescribed in the preceding section, in such form and detail as the commissioner requires, showing the funds held by them.
Mass. Gen. Laws ch. 175, § 156