Final answer:
The appropriate CPT code for a new patient with a Detailed history, Detailed exam, and Low medical decision complexity with a 30-minute consult is 99203.
Step-by-step explanation:
The code used for a new patient who receives a Detailed history, Detailed exam, and has a Low medical decision complexity with a moderate problem or condition during an average time of 30 minutes is 99203. The Current Procedural Terminology (CPT) codes provide a uniform language for reporting medical services and procedures. The level of the code selected is based on the elements documented and the complexity of the medical decision-making as per the American Medical Association guidelines. In this case, the detailed history and exam align with the descriptors for a 99203, assuming the encounter did not involve a comprehensive history/exam or high complexity decision-making which are associated with higher codes such as 99204 or 99205.