Morbid (severe) obesity with alveolar hypoventilation

This code represents a severe form of obesity, specifically morbid obesity, complicated by impaired breathing due to reduced ventilation of the alveoli. This condition, often referred to as Obesity Hypoventilation Syndrome (OHS), involves chronic hypoxemia and hypercapnia in an obese individual, not otherwise explained by other respiratory or neuromuscular disorders.

Apply this code when documentation clearly indicates a diagnosis of morbid obesity (BMI ≥ 40 kg/m² or BMI ≥ 35 kg/m² with significant comorbidities) alongside evidence of chronic alveolar hypoventilation. This typically includes findings such as elevated arterial PCO2 (hypercapnia) and decreased arterial PO2 (hypoxemia) in the absence of other primary lung diseases.

• Always sequence this code first when it is the primary reason for the encounter, followed by codes for associated conditions.
• Ensure documentation specifies "morbid" or "severe" obesity and explicitly links it to "alveolar hypoventilation" or "Obesity Hypoventilation Syndrome."
• Do not use this code for simple obesity with sleep apnea without documented chronic alveolar hypoventilation.