Mass. Gen. Laws ch. 175 § 24B
The commissioner shall require that a policy, contract, agreement, plan or certificate of insurance for coverage of health care services, including any self-insured sickness, health or welfare plan issued within or without the commonwealth and including, but not limited to, those of a non-profit hospital service corporation organized pursuant to chapter one hundred and seventy-six A, a nonprofit medical service corporation organized pursuant to chapter one hundred and seventy-six B, an insurance company licensed pursuant to this chapter, a health maintenance organization organized pursuant to chapter one hundred and seventy-six G and any preferred provider organization organized pursuant to chapter one hundred and seventy-six I, shall provide, the following: (i) to the policyholder, subscriber or, in the case of a group policy, the group representative, prior notice of modifications in covered services under the policy and an annual notice listing all preferred or selective providers of health care services, if applicable; (ii) prior notice to providers of health care services which or who have been regularly paid for services to policyholders or subscribers of such companies of modifications in payments to such providers or modifications in covered services that will be in effect and the effective date of such modifications. Such notices shall include any changes in clinical review criteria, as such term is defined in section 1 of chapter 176O, and a statement of the effect of such changes on the personal liability of the policyholder or subscriber for the cost of any such changes. All notices required by this section shall be provided 60 days before the effective date of such modification. The commissioner shall promulgate regulations to enforce the provisions of this section.
Mass. Gen. Laws ch. 175, § 24B