What is the primary purpose of the CPT codebook's appendices?

The primary purpose of the CPT codebook's appendices is to offer supplementary information such as modifiers, performance measures, and guidelines. These appendices serve as valuable resources that enhance the understanding and application of the codes presented within the main sections of the codebook. For instance, modifiers provide additional context to a code, such as indicating that a procedure was altered in some way, while performance measures can help assess the quality and effectiveness of services provided.

This supplementary information is essential for accurate coding and billing practices, ensuring that healthcare providers can communicate effectively about the services rendered. It is also instrumental in helping coders and healthcare professionals stay compliant with coding standards and guidelines issued by authoritative bodies. The content in the appendices complements the main coding system, rather than serving as primary billing codes or a comprehensive list of diagnoses or payment structures.