That is correct - professional E&M codes are assigned based provider documentation of history, exam, MDM, time, etc. using CPT guidelines. Facility ER levels are assigned based on the use of the facility's resources (e.g. staff time, supplies and equipment used, and other technical elements of the service) and which is usually done with a facility's own internal guidelines rather than through coding guidelines based on physician documentation. So it is entirely possible, and in fact common, that the physician and ER code level for a given encounter may not match.