(1) The purpose of these rules is to:

(a) adopt the Coordination of Benefits Model Regulation, as promulgated by the National Association of Insurance Commissioners (NAIC);

(b) establish a uniform order of benefit determination under which plans pay claims;

(c) establish uniformity in the permissive use of overinsurance provisions and to avoid claim delays and misunderstandings that could otherwise result from the use of inconsistent or incompatible provisions among plans;

(d) reduce duplication of benefits by permitting a reduction of the benefits to be paid by plans that, pursuant to rules established by this subchapter, do not have to pay their benefits first; and

(e) provide greater efficiency in the processing of claims when a person is covered under more than one plan.