Mass. Gen. Laws ch. 176S § 1
As used in this chapter, the following words shall, unless the context clearly requires otherwise, have the following meanings:-
"Carrier", (1) an insurer licensed or otherwise authorized to transact accident or health insurance under chapter 175; (2) a nonprofit hospital service corporation organized under chapter 176A; (3) a nonprofit medical service corporation organized under chapter 176B; (4) a health maintenance organization organized under chapter 176G; (5) an organization entering into a preferred provider arrangement under chapter 176I; (6) a contributory group general or blanket insurance for persons in the service of the commonwealth under chapter 32A; (7) a contributory group general or blanket insurance for persons in the service of counties, cities, towns and districts, and their dependents under chapter 32B; (8) the medical assistance program administered by the office of Medicaid pursuant to chapter 118E and in accordance with Title XIX of the Social Security Act or any successor statute; and (9) any other medical assistance program operated by a governmental unit for persons categorically eligible for such program.
"Commissioner", the commissioner of insurance.
"Insured", an enrollee, covered person, insured, member, policyholder or subscriber of a carrier.
"Nondiscriminatory basis", a carrier shall be deemed to be providing coverage on a non-discriminatory basis if its plan does not contain any annual or lifetime dollar or unit of service limitation imposed on coverage for the care provided by a physician assistant which is less than any annual or lifetime dollar or unit of service limitation imposed on coverage for the same services by other participating providers.
"Participating provider", a provider who, under terms and conditions of a contract with the carrier or with its contractor or subcontractor, has agreed to provide health care services to an insured with an expectation of receiving payment, other than coinsurance, co-payments or deductibles, directly or indirectly from the carrier.
"Physician assistant", a person who is a graduate of an approved program for the training of physician assistants who is supervised by a registered physician in accordance with sections 9C to 9H, inclusive, of chapter 112, and who has passed the Physician Assistant National Certifying Exam or its equivalent.
"Primary care provider", a health care professional qualified to provide general medical care for common health care problems who (1) supervises, coordinates, prescribes, or otherwise provides or proposes health care services; (2) initiates referrals for specialist care; and (3) maintains continuity of care within the scope of practice.
Mass. Gen. Laws ch. 176S, § 1