The code 99204 is used to denote a new patient in the particular office in which the coder is working. Medical coding experts use this code for 47 percent of new visitors to a clinic or doctor's office.
Even though 99204 is the most-used code, strict criteria must be met in order to use it. The doctor must obtain a comprehensive history from the patient, a complete examination must to take place and there should be some level of complexity involved in making the medical diagnosis. Alternatively, the doctor must spend at least 45 minutes with the patient, if the medical coder codes by time.