Question: Texas Subscriber Answer: Sleep services codes (95805-95811) include recording,interpretation, and report. For cases when the neurologist does only the interpretation, use modifier 26 (Professional component) on the sleep study code. All sleep studies must have a minimum of six hours.If the sleep study does not last that long, append modifier 52 (Reduced services) to your code. The multiple wake test measures the patient's ability to stay awake during a time when she is normally awake. During the wakefulness test the physician or technologist records the time it takes the patient to fall asleep during a course of four to five 20-minute nap opportunities provided during the testing period in the sleep lab. The patient does not need to be asleep during the tests.