Massachusetts General Laws Part I. Administration of the Government (Ch. 1-182) Ch. 176C, § 4

No medical service corporation shall, through its own agents or employees, provide any medical services, but any such corporation may enter into an agreement with one or more medical organizations whereby said medical organization or organizations agree to provide specified medical services for the subscribing members of the said medical service corporation; provided, that said agreement shall provide for the payment of a stipulated percentage or percentages of the subscriptions or other receipts, or both, of the medical service corporation to the medical organization and shall not provide for any specific amounts, whether or not based upon the number of services rendered to subscribing members. Any such agreement shall be subject to the approval of the department of public health.