Pulmonology Coding Alert

Plus: Nail down the most common diagnoses.

Giving a patient a continuous positive airway pressure (CPAP) device to try out for three months is more than just an opportunity to see how the patient likes it. This step is critical to Medicare reimbursement.

That was the word from a March 21 presentation by Michael Hanna, MPA, CDME, a provider relations senior analyst with CGS Medicare, where he covered exactly what you need to know if you plan to order CPAP devices for your patients. Read on for the scoop.

Sleep Study Imperative

The CPAP device is typically covered by Medicare for obstructive sleep apnea if the patient has a face-to-face evaluation in which the physician assesses them for the condition, and the patient’s Medicare-covered sleep study confirms one of the following, Hanna said:

• - Apnea-Hypopnea Index (AHI) or Respiratory Disturbance Index (RDI) is at least 15 events per hour, with a minimum of 30 events total
• - AHI or RDI is between five and 14 events per hour, with a minimum of 10 events total and documentation of excessive daytime sleepiness, impaired cognition, mood disorders, or insomnia; OR hypertension, ischemic heart disease or history of stroke

At that point, the patient can try the CPAP for a three-month trial period, during which the patient is expected to use it at least four hours a night on 70 percent of all nights for 30 days straight. At the subsequent E/M session during that trial period, the physician must clinically reevaluate the patient to ensure he or she is benefiting from CPAP therapy. “This must take place no sooner than the 31st day, but no later than the 91st day after initiating therapy,” Hanna said.

When ordering a CPAP device for a patient, the physician must complete the appropriate form including the patient’s name, the DME ordered, date of order, prescribing practitioner’s NPI, and a signature. This order must be completed within six months of the face-to-face examination.

Confirm Diagnosis Code

You’ll also need to assign the most appropriate diagnosis code to the claim when handling sleep apnea. Report G47.30 (Sleep apnea, unspecified) when a patient has nonspecific sleep apnea.

Although this code refers to unspecified sleep apnea, you’ll probably end up using it often, as providers often don’t give coders enough information to choose a more specific code. Go with the unspecified code when neither the diagnostic statement nor the documentation provides enough information to assign a more specific code, and you cannot ask the provider for clarification.

You will instead opt for G47.33 (Obstructive sleep apnea [adult] [pediatric]) when the patient has obstructive sleep apnea.

Obstructive sleep apnea is caused by partial or complete blockage of the airways during sleep. Symptoms of obstructive sleep apnea may include snoring that is loud, disruptive and regular; frequent breaks in breathing cause by an obstruction; morning headaches; restless sleep; and depression or irritability.

Watch out:  Sometimes, a provider diagnoses a patient with unspecified sleep apnea as an initial diagnosis. Then, after testing such as a sleep study, the provider might find that the patient’s apnea is actually obstructive.

When the diagnosis changes from unspecified sleep apnea to obstructive sleep apnea, coders need to be ready to confirm the diagnosis change with the provider and make the proper adjustments to the patient’s medical record. Once patients are tagged with G47.30, the provider often forgets to update the diagnosis to G47.33, when necessary.

Don’t forget secondary codes: The instructions below the descriptor for G47.3- read “Code also any associated underlying condition.” There are several causes and risk factors which can be associated with sleep apnea, including (but not limited to):

• obesity (E66.0- [Obesity due to excess calories...] through E66.9 [Obesity, unspecified]),
• enlarged tonsil or adenoids (J35.3 [Hypertrophy of tonsils with hypertrophy of adenoids]),
• frequent alcohol use (F10.1- [Alcohol abuse...] through F10.99 [Alcohol use, unspecified with unspecified alcohol-induced disorder]), and
• smoking (Z72.0 [Tobacco use]).

Remember: This is not an exhaustive list; there are many conditions that could underlie your patient’s sleep apnea. If you see any of these diagnoses referenced in the encounter notes, however, be sure to include them on your claims for sleep apnea patients.

Although a lot of sleep apnea patients leave the practice with a G47.30 or G47.33 diagnosis, there are other forms of sleep apnea as well, represented by the following diagnosis codes:

• G47.31, Primary central sleep apnea
• G47.32, High altitude periodic breathing
• G47.34, Idiopathic sleep related nonobstructive alveolar hypoventilation
• G47.35, Congenital central alveolar hypoventilation syndrome
• G47.36, Sleep related hypoventilation in conditions classified elsewhere
• G47.37, Central sleep apnea in conditions classified elsewhere.

Best bet: Do your best to gain knowledge on all the forms of sleep apnea, for coding purposes. That way, you can make a quick and correct, decision the next time an apnea claims comes across your desk.

Know These Caveats

One of the most important overlooked aspects of sleep apnea ICD-10 coding concerns G47.36 and G47.37. Notes under both of these ICD-10 entries indicate that you should “Code first underlying condition.” All of the other sleep apnea codes in the G47.3- code set instruct coders to “Code also underlying condition.”

Explanation: According to ICD-10 rules, a “Code also underlying condition” note means that you might need two codes to fully describe a condition, but this note does not provide sequencing direction.

However, certain conditions have both an underlying etiology and multiple body system manifestations due to the underlying etiology. In these instances, you should sequence the underlying condition code first.

So, when you report G47.36 or G47.37 along with an underlying condition, the sleep apnea diagnosis code must fall after the underlying condition code on the claim.