How are add-on codes identified in the CPT codebook?

Add-on codes in the CPT codebook are specifically identified by a "+" sign that precedes the code number. This identifier is crucial because it signifies that the code is meant to be used in conjunction with a primary procedure code and cannot be billed independently. For example, when a procedure requires an additional service that enhances the primary procedure, the add-on code provides clarity and assists in the accurate billing of those additional services.

The use of the "+" sign clearly indicates to healthcare providers and billing personnel that this code is an add-on and reinforces the importance of understanding its context within billing practices. This identification method is standard across the CPT codebook to ensure consistency and prevent confusion during coding and billing processes, aligning with the rules set forth by the American Medical Association.