Question: If the doctor meets the requirements for critical care billing and has spent one full hour with the patient, how would I properly code this for billing purposes? Florida Subscriber Answer: You would use only 99291 (Critical care, evaluation and management of the critically ill or critically injured patient; first 30-74 minutes) in this situation. Critical care occurs when a physician or other qualified healthcare professional directly provides medical services for a critically ill or critically injured patient. The physician usually provides critical care services in a critical care area like the ICU, CCU, or emergency room. As always, the documentation must support the necessity of the critical care service. To qualify for critical care, a service must meet the following requirements: Note: You can use 99291 only once per date.