Which of the following is NOT a category in CPT?

The correct answer is D, as there is no Category IV in the Current Procedural Terminology (CPT) coding system. CPT is divided into three main categories:

Category I includes the most commonly used codes for procedures and services that are widely performed in clinical practice. These codes are organized by sections, including evaluation and management, anesthesia, surgery, radiology, pathology, and laboratory, as well as medicine.

Category II codes are optional tracking codes used for performance measurement. They offer a way to collect data about the quality of care and are not necessary for billing but serve an important role in reporting and performance improvement.

Category III codes are temporary codes used for emerging technologies, services, and procedures that do not yet have a Category I code but are being tracked for data collection and future consideration for standardization.

Since these three categories encompass the full structure of the CPT coding system, the absence of a Category IV confirms that D is the correct choice.