Neurology & Pain Management Coding Alert

The proper coding for an EEG depends on several factors, including the length of time during which the monitoring takes place and whether sleep was achieved during the test. Careful documentation and a firm grasp of carrier rules will help to ensure optimum reimbursement. EEGs are used to diagnose such diverse disorders as dementia (294.8), mental retardation (319), epilepsy (345.xx), cognitive changes and memory loss (780.9), and sleep-related disorders (780.50).

CPTs rules for electroencephalogram (EEG) codes dictate that the full procedure can be billed only if the neurological practice owns the equipment. If the test takes place in another location (like a sleep studies lab), if nonpracticing technicians are employed for monitoring or if it occurs in the operating room during surgery, the codes must be billed with modifier -26 (professional component). When billing for the professional component, the physician should record what was done during the EEG session and the results found. The date of service for the interpretation and report should be billed the same day as the test.

Awake and Drowsy vs. Awake and Asleep

When billing EEGs, coders may question when to use code 95816 (electroencephalogram [EEG] including recording awake and drowsy [including hyperventilation and/or photic stimulation when appropriate]) versus 95819 (electroencephalogram [EEG] including recording awake and asleep [including hyperventilation and/or photic stimulation when appropriate]). According to Larry Seiden, MD, assistant professor of neurology and director of the University of Marylands Center for Sleep Disorders, the awake and drowsy and awake and asleep are used when the neurologist is looking for abnormalities that are associated with the transition from awake to sleep and then from sleep to awake again. For example, a patient comes to see a neurologist because of a seizure (780.39). The coder should bill 99203 for the initial office and append modifier -25 (significant, separately identifiable E/M service by the same physician on the same day of the procedure or other service) indicating the sleep study was done on the same day. Code 95819 should be used for the awake and asleep EEG and 780.39 listed as the diagnosis. The neurologist orders an awake and asleep study because changes that are more commonly associated with epilepsy disorders tend to occur during these periods of transition.

Seiden reports that as a standard he does not code on what was requested, but on what happened during the EEG. If we review it and the person was awake and asleep, then we bill it as 95819; if they did not fall asleep then we bill 95816, Seiden states. The sleep only code (95822) can be used for patients who are comatose, anesthetized, or neonates.

Note: Hyperventilation and photic stimulation are bundled into the EEG service for these codes they cannot be coded separately.

Extended Monitoring

A number of questions concern when to use 95812, (electroencephalogram extended monitoring; up to one hour) and 95813 (greater than one hour). Routine length of monitoring is considered about 20-40 minutes (use 95816, 95819, 95822). Thus, if the extended monitoring went up to one hour then use 95812 which covers approximately 40-60 minutes of monitoring done face-to-face. If the extended is greater than one hour, then use 95813.

Note: CPT 2001 clearly states that you may not bill a routine EEG code (95816, 95819 or 95822) with an extended monitoring code (95812 or 95813). This would be a duplication of service.

Erwin Montgomery, MD, director of the movement disorders program for the Cleveland Clinic in Cleveland, which has more than 40 neurologists on staff, gives the following example: A new patient complains of memory loss (780.9). An EEG that took 50 minutes is performed as an attempt to determine the nature and cause. The coder should bill 99204 for the initial office visit with modifier -25 indicating the study was done on the same day. Code 95812 is for the EEG with extended monitoring and 780.9 for the diagnosis.

(Part Two of this article will cover long-term monitoring, digital analysis, and symptom-based ICD-9 coding for EEGs.)