The question does not address whether or not this is for the facility charge or the physician's fees. When looking at the physician's services, it is proper to bill for two separate encounters as two were rendered. Looking at the CPT code descriptors, an E/R service is biled 9928X and is for Emergency Dept. visit,...which requires these 3 components. It does not state it is a "per day" service. Only the Initial and subsequent observation or hospital care codes, CPT 9922X, are defined as "per day." Now, getting both paid may be an adventure. Your documentation of separate encounters, time of day, reason for service, etc. will be very important, as it will likely require filling an appeal.