Mass. Gen. Laws ch. 171 § 35
A credit union may act as trustee or custodian under a profit-sharing plan instituted by a person, partnership or corporation within the meaning of section 401(a) of the Internal Revenue Code of 1954 including the provisions of P.L. 94-455. A credit union may act as trustee or custodian under a retirement plan or individual retirement account which, in the judgment of such credit union at the time of appointment as such trustee or custodian is accepted, is established pursuant to the provisions of Public Law 87-792, entitled "Self-Employed Individuals' Tax Retirement Act of 1962" or pursuant to the provisions of section 2002 of P.L. 93-406 of the Employees Retirement Income Security Act of 1974, if the provisions of such plan have been approved by the commissioner and if such provisions permit any of the funds of the trust or the custodial accounts to be invested in shares or deposits of the credit union. Such shares or deposits may be in addition to the shares or deposits permitted by section thirty. No funds held by such credit union as such trustee or custodian shall be invested otherwise than in shares or deposits in the credit union or properly qualified life insurance retirement income policies or other investments legal for credit unions or any combination thereof, as each such plan may prescribe or permit. Every advertisement, announcement or solicitation for such a plan or account shall state, in a clear and conspicuous manner, the amounts of any contributions and earnings thereon subject to state and federal taxable income.
Mass. Gen. Laws ch. 171, § 35