Pulmonology Coding Alert

Question: Can you explain CMS's criteria for covering sleep studies, whether they occur in a lab or in the patient's home? Also, is there a minimum amount of time that sleep staging must take place before the pulmonologist initiates CPAP?

North Carolina Subscriber

Answer: The pulmonologist may diagnose obstructive sleep apnea (OSA, 327.23) using one of the following: 1. Polysomnography (PSG) performed in a sleep laboratory (95805, 95807-95811, Sleep study ... attended by a technologist); or 2. An unattended home sleep monitoring device of type II, III, or IV, the latter measuring at least three channels (95806, Sleep study ... unattended by a technologist).

The pulmonologist can establish a diagnosis of OSA if the patient meets either of the following criteria using the Apnea-Hypopnea Index (AHI) or Respiratory Distress Index (RDI):

• The average of AHI or RDI is greater than or equal to 15 events per hour, or

• The average of AHI or RDI is greater than or equal to 5 and less than or equal to 14 events per hour, with documented symptoms of excessive daytime sleepiness, impaired cognition, mood disorders or insomnia, or documented hypertension, ischemic heart disease, or history of stroke.

Remember, if the pulmonologist is calculating AHI or RDI based on less than two hours of continuous recorded sleep, the patient must exhibit as many events in the shorter time frame as the two-hour period requires (CAG-00093R2).

For patients with severe and unambiguous OSA, the pulmonologist may incorporate treatment with a nasal CPAP, or continuous airway pressure device (95811, ... sleep staging ... with initiation of continuous positive airway pressure therapy or bilevel ventilation, attended by a technologist) into the diagnostic study night.

A "split-night" study (initial diagnostic PSG followed by CPAP titration during PSG on the same night) may be an alternative to one full night of diagnostic PSG followed by a second night of titration as long as (a) the pulmonologist carries out CPAP titration for more than three hours, and (b) PSG documents that CPAP significantly improves the patient's breathing during sleep.