I wondered if you could help me with a coding issue that I am having. I have a new physician that is a trauma surgeon. He is giving me paperwork that states Critical Care Time 1:32 and the Dx is Auto accident, concussion. I don't see that Concussion is a critical care Dx. He said he thought that patients seen in the trauma bay are all critical care regardless of their Dx. Can that be true? I'll admit, I've only coded Critical Care as in-patient and perhaps the trauma unit works differently? For inpatient I use 99291 with system failure such as resp failure 518.81. Can I bill 99291 with concussion code 850 even though it's not a MCC code. Maybe he's correct and POS 23 vs. 21 is the difference...... Can you help?