Pulmonology Coding Alert

Look to the ICD-10-CM G codes for sleep apnea diagnoses.

Sleep apnea is a condition that can affect the patient even when they’re not asleep. The condition takes on different forms depending on the factors causing it, and pulmonologists can use attended and unattended sleep studies to evaluate the patient.

Read on to learn about the types of sleep apnea, their diagnostic methods, and the appropriate CPT^® and ICD-10-CM codes for accurate billing and documentation.

Familiarize Yourself With Different Sleep Apnea Types

There are three main types of sleep apnea: obstructive sleep apnea (OSA), central sleep apnea (CSA), and complex sleep apnea syndrome. OSA is the most common condition, caused by a blockage of the airway during sleep. CSA is less common and occurs when the brain does not send the proper signals to the body’s breathing muscles. Complex sleep apnea is a combination of both OSA and CSA.

Each type of sleep apnea has its own causes, symptoms, and risk factors. Below are breakdowns of OSA, CSA, and complex sleep apnea syndrome.

Obstructive Sleep Apnea (OSA)

• Cause: Airway blockage due to relaxed throat muscles during sleep
• Symptoms: Loud snoring, gasping for air during sleep, daytime sleepiness, morning headaches
• Prevalence: Most common type
• Risk factors: Obesity, large neck size, family history, older age, male sex

Central Sleep Apnea (CSA)

• Cause: Brain fails to send proper signals to breathing muscles
• Symptoms: Similar to OSA, but may include shortness of breath upon waking, and difficulty sleeping through the night
• Prevalence: Less common than OSA
• Risk factors: Certain neurological conditions, heart failure, opioid use

Complex Sleep Apnea Syndrome

• Cause: A combination of OSA and CSA
• Symptoms: A mix of symptoms from both OSA and CSA
• Prevalence: Relatively rare

Wake Up Your Sleep Apnea Coding Knowledge

The ICD-10-CM codes for sleep apnea fall under Chapter 6: Diseases of the Nervous System, specifically the G47.3- (Sleep apnea) code subcategory.

The most common ICD-10-CM codes for sleep apnea include:

• G47.33 (Obstructive sleep apnea (adult) (pediatric)): This is the code used when OSA is diagnosed. OSA is characterized by the airway being partially or completely blocked during sleep.

• G47.31 (Primary central sleep apnea): This code is used when CSA is diagnosed. CSA occurs when the brain fails to send proper signals to the muscles that control breathing.

• G47.30 (Sleep apnea, unspecified): This code is used when the specific type of sleep apnea is not identified in the diagnosis. It may be used in preliminary diagnoses before further tests can confirm a specific type. However, it’s generally best to avoid this code if the type of apnea is known, as it could lead to billing delays or denials.

• G47.37 (Central sleep apnea in conditions classified elsewhere): This code is used when CSA is associated with other medical conditions.

• G47.39 (Other sleep apnea): This code can be used for mixed sleep apnea, which involves a combination of both OSA and CSA symptoms.

Understand Sleep Studies and Their Role in Diagnoses

Polysomnography (PSG) is considered the diagnostic gold standard of sleep studies. A PSG is an in-lab sleep study where the patient is monitored overnight in a sleep center. During the study, the provider records various parameters:

• Brain waves (electroencephalogram [EEG])
• Eye movements (electrooculography [EOG])
• Chin and leg movements (electromyography [EMG])
• Heart rate (electrocardiogram [ECG]) and rhythm patterns
• Airflow in and out of the lungs
• Respiratory effort and rate
• Blood oxygen levels (oximetry)
• Body position
• Snoring and other sounds

The specific CPT^® code used depends on the patient’s age and whether continuous positive airway pressure (CPAP) or bilevel ventilation is included in the study.

Diagnostic polysomnography without CPAP/bilevel ventilation codes include:

• 95810 (Polysomnography; age 6 years or older, sleep staging with 4 or more additional parameters of sleep, attended by a technologist)
• 95782 (… younger than 6 years, sleep staging with 4 or more additional parameters of sleep, attended by a technologist)
• 95808 (… any age, sleep staging with 1-3 additional parameters of sleep, attended by a technologist)

You’ll choose from the following codes for therapeutic or split polysomnography with CPAP/bilevel ventilation procedures:

• 95811 (Polysomnography; age 6 years or older, sleep staging with 4 or more additional parameters of sleep, with initiation of continuous positive airway pressure therapy or bilevel ventilation, attended by a technologist)
• 95783 (… younger than 6 years, sleep staging with 4 or more additional parameters of sleep, with initiation of continuous positive airway pressure therapy or bi-level ventilation, attended by a technologist)

Be Mindful of These Important Considerations

Separate PSG billing: Codes 95810 and 95811 should not be billed separately if performed within 30 days of each other. The American Academy of Sleep Medicine states that billing both the diagnostic (95810) and titration (95811) portions separately during a single visit is inappropriate. The Centers for Medicare & Medicaid Services (CMS) specifies billing 95811 only when both procedures are performed in two visits.

Short on time: Append modifier 52 (Reduced services) to codes 95808, 95810, and 95782 if the recording time is less than six hours for patients 6 years and older, or seven hours for patients under 6 years of age.

Additional parameters, such as ECG, airflow, respiratory effort, and oximetry, are included in the codes mentioned above and Medicare does not expect separate billing for these parameters.

Hone Your HSAT Coding Skills

Also known as unattended sleep studies, home sleep apnea tests (HSATs) are performed at home using portable devices. The tests typically measure fewer variables than PSG, often focusing on airflow, respiratory effort, and oxygen saturation to identify sleep-disordered breathing. HSATs are generally recommended for patients with a high likelihood of moderate to severe OSA without other complicating conditions.

Home sleep apnea devices are categorized by the number of variables they measure. Type III devices measure several variables including respiratory, cardiac, and oxygen saturation parameters. Type IV devices measure fewer factors like airflow and blood oxygen. The WatchPAT^™ One is a popular example of a home sleep apnea test that measures seven different parameters.

While HSAT is convenient for the patient, the devices are not without their limitations. HSATs may not be as accurate as PSG, particularly in patients with fragmented sleep, as the devices might overestimate total sleep time and underestimate the apnea-hypopnea index (AHI). They are also not recommended for patients with significant comorbidities like cardiovascular disease, lung disease, neurological conditions, or suspected CSA.

Coding HSAT procedures depend on the simultaneous recordings obtained: 

• 95800 (Sleep study, unattended, simultaneous recording; heart rate, oxygen saturation, respiratory analysis (eg, by airflow or peripheral arterial tone), and sleep time)
• 95801 (… minimum of heart rate, oxygen saturation, and respiratory analysis (eg, by airflow or peripheral arterial tone))
• 95806 (Sleep study, unattended, simultaneous recording of, heart rate, oxygen saturation, respiratory airflow, and respiratory effort (eg, thoracoabdominal movement))

HCPCS Level II G codes are also relevant and vary by the number of channels monitored:

• G0398 (Home sleep study test (HST) with type II portable monitor, unattended; minimum of 7 channels: eeg, eog, emg, ecg/heart rate, airflow, respiratory effort and oxygen saturation)
• G0399 (Home sleep test (HST) with type III portable monitor, unattended; minimum of 4 channels: 2 respiratory movement/airflow, 1 ecg/heart rate and 1 oxygen saturation)
• G0400 (Home sleep test (HST) with type IV portable monitor, unattended; minimum of 3 channels)

Recognize Additional Diagnostic Techniques

Pulmonologists may need to perform additional procedures to evaluate the patient’s condition. Here’s a look at some of those procedures:

• Nasopharyngoscopy and sleep endoscopy: These procedures involve using a flexible fiberoptic endoscope to visualize the upper airway to identify anatomical structures causing obstruction. Sleep endoscopy is performed under mild sedation to simulate sleep conditions.
• Imaging tests: CT scans and MRI can also provide useful information, especially in preoperative evaluations for surgical candidates.
• Split-night study: This combines PSG and positive airway pressure (PAP) titration into a single night. If significant sleep apnea is confirmed in the first half, a PAP device is introduced and adjusted in the second half to determine the optimal pressure setting.

Lori Carlin, CPC, COC, CPCO, CRC, CCS, Principal-Professional Audit,
Coding & Education Services, Pinnacle Enterprise Risk Consulting Services