What is indicated by a code with a "C" following the number in CPT?

A code with a "C" following the number in the Current Procedural Terminology (CPT) is indicative of a category II performance measure. Category II codes are supplemental tracking codes used for performance measurement. They are not used to report procedures or services but rather to assist in collecting data on the quality of care provided. These codes help facilitate the reporting of performance measures in a standardized way, supporting quality improvement initiatives in healthcare.

In the context of coding, category II codes allow healthcare providers to document and track quality metrics related to the care they deliver, which can influence reimbursement and highlight areas for improvement. These codes serve an important role in health initiatives and research, contributing to better patient care outcomes.