No nonprofit medical service corporation subject to the provisions of this chapter shall discontinue reimbursement or providing services for the covered healthcare services of chronic disabilities unless the patient has exhausted benefits to which he or she is entitled under the basic subscriber agreement, or unless it is at the end of the open enrollment period, provided notice of the discontinuation is sent to subscribers who have been reimbursed for or utilized those services in the past three (3) years. The notice shall be mailed at least sixty (60) days prior to the beginning of the open enrollment period. For the purposes of this section, “chronic disability” means an impairment or illness that is likely to continue indefinitely.