Routine lab and X-ray services do not require prior authorization. High-tech radiology services, such as CTs, MRIs, MRAs, PETs, and SPECTs, require prior authorization; refer to the PPO Prior Authorization Requirements List for additional information. Participating physicians are required to refer members to Health Net PPO participating providers for lab and X-ray services, if available in their service area. Refer to the ancillary provider section of the provider directory, contact the Health Net Provider Services Department or consult the Health Net website.