section 1302(8)(c) of the Public Health Services (PHS) Act [42 USC 300e-1]
§ 300e-1.  Definitions

For purposes of this title:
   (1) The term "basic health services" means--
      (A) physician services (including consultant and referral services by a physician);
      (B) inpatient and outpatient hospital services;
      (C) medically necessary emergency health services;
      (D) short-term (not to exceed twenty visits), outpatient evaluative and crisis intervention mental health services;
      (E) medical treatment and referral services (including referral services to appropriate ancillary services) for the abuse of or addiction to alcohol and drugs;
      (F) diagnostic laboratory and diagnostic and therapeutic radiologic services;
      (G) home health services; and
      (H) preventive health services (including (i) immunizations, (ii) well-child care from birth, (iii) periodic health evaluations for adults, (iv) voluntary family planning services, (v) infertility service, and (vi) children's eye and ear examinations conducted to determine the need for vision and hearing correction).
   Such term does not include a health service which the Secretary, upon application of a health maintenance organization, determines is unusual and infrequently provided and not necessary for the protection of individual health. The Secretary shall publish in the Federal Register each determination made by him under the preceding sentence. If a service of a physician described in the preceding sentence may also be provided under applicable State law by a dentist, optometrist, podiatrist, psychologist, or other health care personnel a health maintenance organization may provide such service through a dentist, optometrist, podiatrist, psychologist, or other health care personnel (as the case may be) licensed to provide such service. For purposes of this paragraph, the term "home health services" means health services provided at a member's home by health care personnel, as prescribed or directed by the responsible physician or other authority designated by the health maintenance organization.
   (2) The term "supplemental health services" means any health service which is not included as a basic health service under paragraph (1) of this section. If a health service provided by a physician described in the preceding sentence may also be provided under applicable State law by a dentist, optometrist, podiatrist, psychologist, or other health care personnel a health maintenance organization may provide such service through an optometrist, dentist, podiatrist, psychologist, or other health care personnel (as the case may be) licensed to provide such service.
   (3) The term "member" when used in connection with a health maintenance organization means an individual who has entered into a contractual arrangement, or on whose behalf a contractual arrangement has been entered into, with the organization under which the organization assumes the responsibility for the provision to such individual of basic health services and of such supplemental health services as may be contracted for.
   (4) The term "medical group" means a partnership, association, or other group--
      (A) which is composed of health professionals licensed to practice medicine or osteopathy and of such other licensed health professionals (including dentists, optometrists, podiatrists, and psychologists) as are necessary for the provision of health services for which the group is responsible;
      (B) a majority of the members of which are licensed to practice medicine or osteopathy; and
      (C) the members of which (i) as their principal professional activity engage in the coordinated practice of their profession and as a group responsibility have substantial responsibility for the delivery of health services to members of a health maintenance organization, except that this clause does not apply before the end of the forty-eight month period beginning after the month in which the health maintenance oranization becomes a qualified health maintenance oranization [organization] as defined in section 1310(d) [42 USCS § 300e-9(d)], or as authorized by the Secretary in accordance with regulations that take into consideration the unusual circumstances of the group; (ii) pool their income from practice as members of the group and distribute it among themselves according to a prearranged salary or drawing account or other similar plan unrelated to the provision of specific health services; (iii) share medical and other records and substantial portions of major equipment and of professional, technical, and administrative staff; (iv) arrange for and encourage continuing education in the field of clinical medicine and related areas for the members of the group; and (v) establish an arrangement whereby a member's enrollment status is not known to the health professional who provides health services to the member.
   (5) The term "individual practice association" means a partnership, corporation, association, or other legal entity which has entered into a services arrangement (or arrangements) with persons who are licensed to practice medicine, osteopathy, dentistry, podiatry, optometry, psychology, or other health profession in a State and a majority of whom are licensed to practice medicine or osteopathy. Such an arrangement shall provide--
      (A) that such persons shall provide their professional services in accordance with a compensation arrangement established by the entity; and
      (B) to the extent feasible, for the sharing by such persons of medical and other records, equipment, and professional, technical, and administrative staff.
   (6) The term "health systems agency" means an entity which is designated in accordance with section 1515 of this Act.
   (7) The term "medically underserved population" means the population of an urban or rural area designated by the Secretary as an area with a shortage of personal health services or a population group designated by the Secretary as having a shortage of such services. Such a designation may be made by the Secretary only after consideration of the comments (if any) of (A) each State health planning and development agency which covers (in whole or in part) such urban or rural area or the area in which such population group resides, and (B) each health systems agency designated for a health service area which covers (in whole or in part) such urban or rural area or the area in which such population group resides.
   (8) (A) The term "community rating system" means the systems, described in subparagraphs (B) and (C), of fixing rates of payments for health services. A health maintenance organization may fix its rates of payments under the system described in subparagraph (B) or (C) or under both such systems, but a health maintenance organization may use only one such system for fixing its rates of payments for any one group.
      (B) A system of fixing rates of payment for health services may provide that the rates shall be fixed on a per-person or per-family basis and may authorize the rates to vary with the number of persons in a family, but, except as authorized in subparagraph (D), such rates must be equivalent for all individuals and for all families of similar composition.
      (C) A system of fixing rates of payment for health services may provide that the rates shall be fixed for individuals and families by groups. Except as authorized in subparagraph (D), such rates must be equivalent for all individuals in the same group and for all families of similar composition in the same group. If a health maintenance organization is to fix rates of payment for individuals and families by groups, it shall--
         (i) (I) classify all of the members of the organization into classes based on factors which the health maintenance organization determines predict the differences in the use of health services by the individuals or families in each class and which have not been disapproved by the Secretary,
            (II) determine its revenue requirements for providing services to the members of each class established under subclause (I), and
            (III) fix the rates of payments for the individuals and families of a group on the basis of a composite of the organization's revenue requirements determined under subclause (II) for providing services to them as members of the classes established under subclause (I), or
         (ii) fix the rates of payments for the individuals and families of a group on the basis of the organization's revenue requirements for providing services to the group, except that the rates of payments for the individuals and families of a group of less than 100 persons may not be fixed at rates greater than 110 percent of the rate that would be fixed for such individuals and families under subparagraph (B) or clause (i) of this subparagraph.
      The Secretary shall review the factors used by each health maintenance organization to establish classes under clause (i). If the Secretary determines that any such factor may not reasonably be used to predict the use of the health services by individuals and families, the Secretary shall disapprove such factor for such purpose. If a health maintenance organization is to fix rates of payment for a group under clause (ii), it shall, upon request of the entity with which it contracts to provide services to such group, disclose to that entity the method and data used in calculating the rates of payment.
      (D) The following differentials in rates of payments may be established under the systems described in subparagraphs (B) and (C):
         (i) Nominal differentials in such rates may be established to reflect differences in marketing costs and the different administrative costs of collecting payments from the following categories of members:
            (I) Individual members (including their families).
            (II) Small groups of members (as determined under regulations of the Secretary).
            (III) Large groups of members (as determined under regulations of the Secretary).
         (ii) Nominal differentials in such rates may be established to reflect the compositing of the rates of payment in a systematic manner to accommodate group purchasing practices of the various employers.
         (iii) Differentials in such rates may be established for members enrolled in a health maintenance organization pursuant to a contract with a governmental authority under section 1079 or 1086 of title 10, United States Code, or under any other governmental program (other than the health benefits program authorized by chapter 89 of title 5, United States Code [5 USCS §§ 8901 et seq.]) or any health benefits program for employees of States, political subdivision of States, and other public entities.
   (9) The term "non-metropolitan area" means an area no part of which is within an area designated as a standard metropolitan statistical area by the Office of Management and Budget and which does not contain a city whose population exceeds fifty thousand individuals.