Massachusetts General Laws Part I. Administration of the Government (Ch. 1-182) Ch. 118E, § 56

The division shall establish a controlled substance management program for MassHealth enrollees who use excessive quantities of prescribed drugs. Those enrollees shall be restricted to obtaining prescription drugs only from the provider that the division designates as the enrollee's primary pharmacy. The division shall promulgate regulations relative to the program, including criteria for participation, service restriction, responsibilities of the primary pharmacy, change in the primary pharmacy and participation status, utilization review and enforcement.