(1) Once a health maintenance organization has been in operation at least five years, or has enrollment of not less than fifty thousand persons, the health maintenance organization shall, in any year following a year in which the health maintenance organization has achieved an operating surplus, maintain an open enrollment period of at least thirty days during which time the health maintenance organization shall, within the limits of its capacity, accept individuals in the order in which they apply without regard to preexisting illness, medical conditions or degree of disability except for individuals who are confined to an institution because of chronic illness or permanent injury: Provided, That no health maintenance organization shall be required to continue an open enrollment period after such time as enrollment pursuant to the open enrollment period is equal to three percent of the health maintenance organization's net increase in enrollment during the previous year.

(2) Where a health maintenance organization demonstrates to the satisfaction of the commissioner that it has a disproportionate share of high-risk enrollees and that, by maintaining open enrollment, it would be required to enroll so disproportionate a share of high-risk enrollees as to jeopardize its economic viability, the commissioner may:

(a) Waive the requirement for open enrollment for a period of not more than three years; or

(b) Authorize the organization to impose any underwriting restrictions upon open enrollment as are necessary: (i) To preserve its financial stability; (ii) to prevent excessive adverse selection by prospective enrollees; or (iii) to avoid unreasonably high or unmarketable charges for enrollee coverage of health services. A health maintenance organization may receive more than one waiver or authorization.