(1) No insurer shall increase the premium unilaterally or decrease the coverage benefits previously provided as contained in a medical malpractice policy unless such insurer mails by first-class mail to the named insured, at the last address shown in the insurer's records, at least ninety days' advance notice, accompanied by the reason therefor, of the company's intention to increase the premium unilaterally or decrease the coverage benefits provided on renewal.
(2) A notice of a decrease in coverage benefits previously provided pursuant to this section shall be valid only if it sets forth the reason for the decrease and is based on one or more of the following reasons:
(a) Nonpayment of premium;
(b) A false statement knowingly made by the insured on the application for insurance;
(c) A substantial change in the exposure or risk other than that indicated in the application and underwritten as of the effective date of the policy unless the insured has notified the insurer of the change and the insurer accepts such change.
(3) This section shall not apply to insurers providing coverage for exempt commercial policyholders, as defined pursuant to section 10-4-1402 and rules adopted by the commissioner pursuant to that section.