Michigan Subscriber
Answer: CPT includes an explanatory paragraph preceding the electroencephalography (EEG) codes (95812-95827) that states, "Routine EEG codes 95816-95822 include 20 to 40 minutes of recording. Extended EEG codes 95812-95813 include reporting times longer than 40 minutes" [emphasis added]. This time difference is what qualifies 95812 (Electroencephalogram [EEG] extended monitoring; 41-60 minutes) and 95813 (... greater than one hour) as extended.
And, for 24-hour EEG monitoring (for localization of seizures, for instance), you should access codes 95950-95953 or 95956.
CPT excludes 95824-95829 from any definition that includes a time component. These services, including cerebral death evaluation, all-night EEG recording and electrocorticogram at surgery, are valued according to the nature of the service, not the time the physician requires to complete it.