215 ILCS 93/20

(a) A small employer carrier may establish a separate class of business only to reflect substantial differences in expected claims experience or administrative costs related to the following reasons: (1) the small employer carrier uses more than one type of system for the marketing and sale of health benefit plans to small employers; (2) the small employer carrier has acquired a class of business from another small employer carrier; or (3) the small employer carrier provides coverage to one or more association groups. (b) A small employer carrier may establish up to 4 separate classes of business under subsection (a). (c) The Director may approve the establishment of additional classes of business upon application to the Director and a finding by the Director that such action would enhance the efficiency and fairness of the small employer marketplace.