Final answer:
The correct code for an established patient with an 'Expanded history, Expanded exam, Low medical decision; Presenting problem: low to moderate: avg. time: 15 minutes' is 99213. This code is used for office or other outpatient visits fitting the described scenario.
Step-by-step explanation:
Coding for Established Patients
The correct code for an established patient who has received an expanded history and expanded exam, with low medical decision-making and a presenting problem that is low to moderate severity, and with an average time of 15 minutes, is 99213. This code reflects an office or other outpatient visit that typically requires these specific components. Code 99212 would denote a problem-focused history and exam with straightforward medical decision-making, while 99214 and 99215 represent higher complexity and longer patient encounters.
When choosing the proper code for billing purposes, healthcare providers should consider the nature of the patient visit, the level of history and exam, the complexity of medical decision-making, and the time spent with the patient. For the given scenario, an expanded history and exam with low medical decision-making corresponds to 99213.