Question: Our staff completed a portable sleep study in the patient's home (staged, with three additional parameters). The physician was immediately available by phone, and the sleep technologist monitored the parameters off-site via modem connection all night. How should I code this? Oklahoma Subscriber Answer: Consider the service an unattended study, which you code as 95806 (Sleep study, simultaneous recording of ventilation, respiratory effort, ECG or heart rate, and oxygen saturation, unattended by a technologist). Physicians sometimes try to report these studies as "attended" with 95807 (Sleep study, simultaneous recording of ventilation, respiratory effort, ECG or heart rate, and oxygen saturation, attended by a technologist). The only way to bill an attended study, however, is for the technologist to be physically in the facility with the patient during the test. Any other situation -- such as the one you describe -- is coded as unattended.