Billing 99204 (Moderate Complexity) or 99205 (High Complexity) is heavily audited because these are the highest-paying office visit codes for new patients.
The "New Patient" 3-Year Rule
A new patient is one who has not received any professional services (E/M or surgical) from the physician, or another physician of the exact same specialty and subspecialty within the same group practice, within the past exactly 3 years.
Time vs. MDM for 99204 and 99205
If billing by time:
- 99204: 45 - 59 minutes total time
- 99205: 60 - 74 minutes total time
If billing by MDM, a 99205 requires a "High" level of complexity, meaning severe exacerbations, threats to life/bodily function, or decisions regarding major surgery with identified risk factors.
NCCI Edit Warnings
If a new patient requires an immediate minor procedure during the visit, you must append Modifier 25 to the 99204/99205. Check your NCCI combinations carefully.