Massachusetts General Laws Part I. Administration of the Government (Ch. 1-182) Ch. 175, § 122B

(a) No insurer authorized to issue policies on the lives of persons in the commonwealth shall make a distinction or otherwise discriminate between persons, reject an applicant, cancel a policy or demand or require a higher rate of premium for reasons based solely upon the fact that an applicant or insured has or had a prescription for, purchased or otherwise possessed an opioid antagonist, as defined in section 19B of chapter 94C.

(b) A violation of this section shall constitute an unfair method of competition or unfair and deceptive act or practice pursuant to chapters 93A and 176D.