When you receive a bill for medical treatment, there are generally two choices. You can pay the bill and then get a refund from your OSHC insurer, or the unpaid account can be given directly to your OSHC insurer. For pharmaceutical claims, you need to pay the chemist first and then claim back from your health insurer.
Hospital bills are normally sent directly to the OSHC insurer for payment. However, arrangements for payment of treatment expenses will vary between OSHC insurers. You should contact your OSHC insurer for further information.