Oklahoma REFERRAL OF PATIENT TO ANOTHER PHYSICIAN is a process in which a patient's primary physician sends the patient to another physician for additional care or treatment. This process is used when the patient's primary physician believes that another physician with more specialized training and experience is better suited to provide the care or treatment the patient needs. Types of referral in Oklahoma include: Specialist Referral, Second Opinion Referral, Complex Care Referral, and Emergency Referral.