Unless otherwise specified by the plan, as a prerequisite for payment from the plan, each provider of health services to persons covered under the plan shall enter into a provider agreement with the association under which reimbursement for services provided shall be at rates established by the board. Providers shall not charge persons covered under the plan with the exception of authorized deductible and co-pay requirements and noncovered services if the recipient has been informed in advance of the noncoverage. See definition section Kan. Stat. Ann. § 40-2118.