SDCL § 58-18A-64: Closed panel plans.

Under the terms of a closed panel plan, no benefits are payable if the covered person does not use the services of a closed panel provider. No COB occurs if a covered person is enrolled in two or more closed panel plans and obtains services from a provider in one of the closed panel plans because the other closed panel plan (the one whose providers were not used) has no liability. However, COB may occur during the plan year if the covered person receives emergency services that would have been covered by both plans. In such a case, the secondary plan shall use the provisions of § 58-18A-75 to determine the amount it should pay for the benefit.