(b) Effective the first day of July, two thousand eight, the authority, or its contracted medical providers, may not pay an amount to an outside provider of a medical service for a person residing in a regional jail greater than the reimbursement rate applicable to service providers established by legislative rule of the Bureau for Medical Service within the Department of Health and Human Resources: Provided, That critical access hospitals shall be reimbursed at seventy-five percent of the billed charges. This limitation applies to all medical care services, goods, prescription drugs and medications provided to a person who is in the custody of a regional jail and is provided these services outside of a regional jail: Provided, however, That the Department of Military Affairs and Public Safety and the Department of Health and Human Resources effectuate an interagency agreement for the electronic processing and payment of medical services.