For purposes of rate making and requests for rate increase.

(1) The actuary responsible for setting premium rates shall group similar contract forms, including forms no longer being marketed if issued on or after January 1, 1988, in the pricing calculations. Such grouping shall rely on the judgment of the pricing actuary and be satisfactory to the commissioner. Among the factors which shall be considered are similar claims experience, types of benefits, reserves, margins for contingencies, expenses and profit, and equity between contract holders. Such grouping shall enhance statistical reliability and improve the likelihood of premium adequacy without introducing elements of discrimination in violation of RCW 48.44.220 or 48.46.370.

(2) The insureds under similar contract forms are grouped at the time of rate making in accord with RCW 48.44.220 or 48.46.370 because they are expected to have substantially like insuring, risk and exposure factors and expense elements. The morbidity and mortality experience of these insureds will, as a group, deteriorate over time. It is hereby defined to be an unfair discriminatory practice and therefore prohibited pursuant to RCW 48.44.220 or 48.46.370 and 48.84.040(3) to withdraw a form from its assigned grouping by reason of the deteriorating health of the insureds covered thereunder.

(3) One or more of the contract forms grouped for rate making purposes may, by random chance, experience significantly higher or more frequent claims than the other forms. It is hereby defined to be an unfair discriminatory practice and therefore prohibited pursuant to RCW 48.44.220 or 48.46.370, to deviate from the assigned grouping of contract forms for pricing purposes at the time of requesting a rate increase unless the pricing actuary can justify to the satisfaction of the commissioner that a different grouping is more equitable because of some previously unrecognized and nonrandom distinction between forms or between groups of insureds.

(4) Successive contract forms of similar benefits are sometimes introduced by health care service contractors and health maintenance organizations for the purpose of keeping up with trends in hospital costs, new developments in medical practice, additional supplemental benefits offered by competitors, and other reasons. While this is commendable, contract holders who can not qualify for the new improved contracts, or to whom the new benefits are not offered, are left isolated as a high risk group under the prior form and soon become subject to massive rate increases. It is hereby defined to be an unfair discriminatory practice and therefore prohibited pursuant to RCW 48.44.220 or 48.46.370 and 48.84.040(3), to fail to combine successive generic contract forms and to fail to combine contract forms of similar benefits covering generations of contract holders in the calculation of premium rate and loss ratios.