When permission is requested, the insurance company will check the patient’s policy and make sure the procedure codes are billable and reimbursable under the patient’s plan. If the codes are billable  the medical director will review the letter of medical necessity and supporting documentation and grant an approval/denial or inform+ you that no pre-authorization is required. This decision is decided by the medical director and nurse reviewer at the insurance company. If you are granted approval, then you can render services.