How do you decide the length of a routine EEG?

A routine EEG, defined by codes 95819 or 95816, typically lasts 20-40 minutes or up to an hour. Studies lasting 1 to 2 hours (code 95813) lack a clear rationale and are not commonly utilized. "Prolonged" EEGs are the newer (2020) codes that depend on duration and whether or not there is video.

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