The plus sign (+) in front of code 20930 indicates that this code is a(n) __________.

The presence of a plus sign (+) in front of code 20930 indicates that this code is an add-on code. Add-on codes are used in conjunction with primary procedure codes to provide a more comprehensive description of the services rendered. They are typically reported in addition to a main procedure and are usually related to the primary service. In the case of 20930, it relates specifically to the use of lower extremity nerve blocks, and the plus sign signals that it should not be billed alone but rather alongside a specified primary procedure code.

This coding system allows for better granularity in billing and ensures that healthcare providers can more accurately bill for complex procedures that require additional interventions. Understanding how add-on codes function is critical for proper coding and billing practices, as they help to depict the full scope of procedures done in a single patient encounter.