Part B Insider (Multispecialty) Coding Alert

Coding these procedures incorrectly could raise a red flag for auditors.

They may seem similar, but there's a big difference between your physician conducting a "sleep study" versus a "polysomnography." Here's how to report the right code for the right procedure to help ensure your physician is getting his due.

Polysomnography and Sleep Studies Are Not Synonymous

CPT currently includes three codes for polysomnography:

• 95808 -- Polysomnography; sleep staging with 1-3 additional parameters of sleep, attended by a technologist
• 95810 -- ... sleep staging with 4 or more additional parameters of sleep, attended by a technologist
• 95811 -- ... sleep staging with 4 or more additional parameters of sleep, with initiation of continuous positive airway pres-sure therapy or bilevel ventilation, attended by a technologist.

The CPT section guidelines for Sleep Testing Procedures lists the additional parameters of sleep referenced in these code descriptions as: 1) ECG; 2) airflow; 3) ventilation and respiratory effort; 4) gas exchange by oximetry, transcutaneous monitoring, or end tidal gas analysis; 5) extremity muscle activity, motor activity-movement; 6) extended EEG monitoring; 7) penile tumescence; 8) gastroesophageal reflux; 9) continuous blood pressure monitoring; 10) snoring; 11) body positions; etc.

Tip from the field: A standard polysomnogram -- code 95810, for example -- makes limited use of EEG recording, and these diagnostic studies typically do not provide enough information for a physician to make a diagnosis, says Paul Zyglewski of Neurology Consults, P.C., in Smyrna, Tenn. A variety of neurologic disorders, including sleep-related epilepsy, may require a more in-depth EEG study. Polysomnography involves an overnight recording of data with the patient being monitored throughout the night.

"A basic EEG can be done in an awake or asleep state, and monitors brainwaves," says Gabriela Gregory, MD, in Las Vegas. "It can be used to monitor the different characteristic patterns in an awake or asleep state as well as any activity caused by stimulation such as a strobe light or hyperventilation. The EEG is used in conjunction with a sleep study or polysomnography to define the different sleep stages, as well as monitor brain activity in those stages."

Sleep Studies Do Have Separate Codes

On the other hand, the following codes refer specifically to sleep studies:

• 95805 -- Multiple sleep latency or maintenance of wakefulness testing, recording, analysis and interpretation of physiological measurements of sleep during multiple trials to assess sleepiness
• 95806 --  Sleep study, simultaneous recording of ventilation, respiratory effort, ECG or heart rate, and oxygen saturation, unattended by a technologist
• 95807 -- Sleep study, simultaneous recording of ventilation, respiratory effort, ECG or heart rate, and oxygen saturation, attended by a technologist.

Term tip: The multiple sleep latency test (MSLT) and the maintenance of wakefulness test (MWT) are similar in that they both are measures of sleepiness during daytime hours. In the MSLT, the patient is instructed to try to fall asleep, whereas the MWT is monitored through multiple trials throughout a day of low-demand activities when the patient is instructed to resist sleep.

Sleep Staging -- Separate Pay

The AMA's Sept. 2002 CPT Assistant addressed the differences between these sleep codes, saying "MSLT or MWT and polysomnography represent separate diagnostic tests that are performed at different times to access various physiological parameters of sleep."

A polysomnography is most often performed the night before a MSLT or MWT. For example, a Monday night polysomnography ends on the following Tuesday morning. The MSLT procedure begins several hours later on Tuesday, on a separately billed day of service.

What you need to know: Sleep testing differs from polysomnography in that the latter requires the presence of sleep staging, according to the Correct Coding Initiative (CCI) Policy Manual for Medicare Services and CPT 2008. "Sleep staging includes a qualitative and quantitative assessment of sleep as determined by standard sleep scoring techniques," the CCI manual states. Therefore, you should not report a sleep study and polysomnography together for the same session.

EEGs Must Be a Distinct Service

Sleep staging includes a one- to four-lead electroencephalogram (EEG), electrooculogram (EOG), and submental electromyogram (EMG). Polysomnography typically uses several EEG leads, but has different requirements than those of diagnostic EEG testing (such as the number of channels or speed of paper). Polysomnography inc-ludes extended EEG monitoring.

Continuous EEG monitoring services (95950-95962) represent different services than those provided during sleep testing, according to the CCI manual. You should report these EEG codes when the physician performs and documents a separately identifiable diagnost-ic study.

Billing routine EEG services (95812-95830) is appropriate only if a significant, separately identifiable service is provided by your physician. Report these codes with modifier 59 (Distinct procedural service) to indicate that your physician clearly performed and documented a separate and distinct diagnostic service.