Mass. Gen. Laws ch. 23G § 9
The bonds of the Agency and any loan or extension of credit which is the subject of insurance or reinsurance or an insurance or reinsurance commitment pursuant to sections 4 and 5, shall be legal investments in which all public officers and public bodies of the commonwealth, its political subdivisions, all municipalities and municipal subdivisions, all insurance companies and associations and other persons carrying on an insurance business, all banks, banking associations, trust companies, savings banks and savings associations, including cooperative banks, building and loan associations, investment companies and other persons carrying on a banking business, and all other persons whatsoever who are now or may hereafter be authorized to invest in bonds or other obligations of the commonwealth, may properly and legally invest funds, including capital, in their control, or belonging to them. The bonds and any loan or extension of credit which is the subject of insurance or reinsurance or an insurance or reinsurance commitment pursuant to said sections 4 and 5 are also hereby made securities which may properly and legally be deposited with and received by all public officers and bodies of the commonwealth or any Agency or political subdivisions thereof and all municipalities and public corporations for any purpose for which the deposit of bonds or other obligations of the commonwealth is now or may hereafter be authorized by law.
Mass. Gen. Laws ch. 23G, § 9