ICD-10 Code E66.2 – Morbid (severe) obesity with alveolar hypoventilation (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code E66.2 – Morbid (severe) obesity with alveolar hypoventilation
What it is
E66.2 identifies morbid, or severe, obesity complicated by alveolar hypoventilation. Use it when excess body weight is documented with impaired breathing that leads to inadequate ventilation.
Clinical signs
Clinical features may include obesity with daytime hypoventilation, sleep-related breathing problems, and chronic carbon dioxide retention. Clinical features vary; refer to documentation.
When to use this code
Use E66.2 when the record clearly states severe obesity with obesity-related hypoventilation syndrome or alveolar hypoventilation. It is appropriate when the provider links the breathing disorder to obesity, not when obesity is present without that connection.
Do not use for
Do not use this code for obesity alone, sleep apnea without documented hypoventilation, or hypoventilation from another cause. Check documentation if the cause of breathing impairment is unclear.
Coding tip
Confirm that the provider documents both severe obesity and obesity-related hypoventilation before assigning E66.2.