Mass. Gen. Laws ch. 176C, § 11

The funds of any corporation subject to this chapter shall be kept only in banks in which funds of the commonwealth are authorized to be deposited, or by depositing on paid-up shares and accounts of and in co-operative banks, or by investing in share accounts of federal savings and loan associations located in this commonwealth in accordance with the authority and limitations specified in section ten of chapter one hundred and seventy-six B.