(1) Under the authority of this section and section 41-2216, Idaho Code, the director shall promulgate rules that are in accordance with the model regulations of the national association of insurance commissioners relating to coordination of benefits provisions in individual and group disability insurance policies. This section shall apply to all policies of individual disability insurance or coverage issued in this state pursuant to the provisions of chapters 21, 34, 39 and 52, title 41, Idaho Code. These rules shall establish uniformity in the permissive use of provisions governing the coordination of benefits between individual disability policies and between individual disability policies and group disability policies in order to avoid claim delays and misunderstandings that otherwise result from the use of inconsistent or incompatible provisions.
(2)  Any provision contained in a policy of disability insurance providing for a reduction of benefits payable under the policy during a policy benefit period due to an increase in benefits payable under the federal social security act, as amended, shall be null and void with respect to any such increase which occurs on or after the effective date of this act.