E/M is a fickle creature at best, but there are some help and guidelines out there to help tame the beast. Because CMS has not given us any quantifiable guidelines, but basing them on medical necessity (qualitative), then the auditing becomes very subjective. Some companies (like AAPC), has attempted to streamline the E/M auditing process by implementing the Marshfield Clinic Tool (point system for Medical Decision Making), and while CMS has noticed this tool, they have not necessarily accepted it.
With that said, I can give you some references, reading material, tips & tricks, along with answering any specific questions you might have:
CMS E/M guildelines - I always start out with these as the base line, and then go from there
Local MAC - Depending on where the provider practices, there might be some local E/M guidelines. My MAC is Noridian as I live on the West coast, but will be different if you live in a different state.
E/M University - Another good resource created my an actual MD (and CPC coder). Some of his stuff is free, and there are some you can pay for.
AAPC E/M Online Course - Definitely not free, but another resource if you need a refresher. Also, consider grabbing the E/M Exam
Study Guide and/or Practice Exams.
AAPC did a free
PowerPoint presentation as an overview. It's from 2012, but could still be helpful.
E/M Audit Tools:
NGS Audit Tool (MAC)
Highmark Virginia BCBS Audit Tool
Novitas Interactive Audit Tool
Novitas Paper Audit Tool
However to directly answer your question, the E/M level always boils down to provider documentation. Based on the information you are providing, the E/M level would likely be a 99203, as the 99204 requirements are as follows:
The documentation for a 99204 requires THREE out of THREE of the following :
1)
Comprehensive History
2)
Comprehensive Exam
3)
Moderate Complexity Medical Decision-Making
Don't forget that in order to bill a New Patient level, the patient has to be classified as a New Patient (less than 3 years of last visit).
Hope this helps!