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

A group health maintenance contract shall provide coverage for off-label uses of prescription drugs used in the treatment of cancer as set forth in sections forty-seven K and forty-seven L of chapter one hundred and seventy-five; provided, however, that neither the attending physician nor the health maintenance organization shall be liable in a suit for damages as a result of the acts or omissions of the attending physician or the health maintenance organization in connection with compliance with this section.