Section 1. As used in this chapter, the following words shall have the following meanings unless the context clearly requires otherwise:

''Carrier'', an insurer licensed or otherwise authorized to transact accident or health insurance under chapter 175; a nonprofit hospital service corporation organized under chapter 176A; a nonprofit medical service corporation organized under chapter 176B; a health maintenance organization organized under chapter 176G; an organization entering into a preferred provider arrangement under chapter 176I; a contributory group general or blanket insurance for persons in the service of the commonwealth under chapter 32A; a contributory group general or blanket insurance for persons in the service of counties, cities, towns and districts, and their dependents under chapter 32B; the medical assistance program administered by the division of medical assistance pursuant to chapter 118E and in accordance with Title XIX of the Social Security Act or any successor statute; and 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 nurse practitioner 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.

''Nurse practitioner'', a registered nurse who holds authorization in advanced nursing practice as a nurse practitioner under section 80B of chapter 112 and regulations promulgated thereunder.

''Participating provider'', a provider who, under the 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.

''Primary care provider'', a health care professional qualified to provide general medical care for common health care problems, supervises, coordinates, prescribes, or otherwise provides or proposes health care services, initiates referrals for specialist care, and maintains continuity of care within the scope of practice.