E66.2 Morbid (severe) obesity with alveolar hypoventilation

Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis.

Applicable to

• Obesity hypoventilation syndrome (OHS)
• Pickwickian syndrome

Applies from E66 Overweight and obesity

Excludes2 (not included here)

• adiposogenital dystrophy (E23.6)
• lipomatosis dolorosa [Dercum] (E88.2)
• lipomatosis NOS (E88.2)
• Prader-Willi syndrome (Q87.11)

Code first

• obesity complicating pregnancy, childbirth and the puerperium, if applicable (O99.21-)

Use additional code

• code to identify body mass index (BMI), if known, for adults (Z68.1-Z68.45) or pediatrics (Z68.5-)

Risk adjustment (HCC)

• CMS-HCC V28: HCC 48 — Morbid Obesity
• CMS-HCC V22: HCC 22 — Morbid Obesity
• ESRD V24: HCC 22

MS-DRG index

Defines the logic of DRG(s) 205-206 in MDC 04.

Approximate ICD-9-CM (GEMs)

• 278.03 Obesity hypoventilation syndrome

Code annotations containing back-references to E66.2

Back-references to E66.2

• Type 1 Excludes: E66.01 Morbid (severe) obesity due to excess calories ("morbid (severe) obesity with alveolar hypoventilation (E66.2)")
• Type 1 Excludes: G47.3 Sleep apnea ("pickwickian syndrome (E66.2)")

Back-references to E66

• Use Additional: E88.81 Metabolic syndrome and other insulin resistance ("obesity (E66.-)")
• Use Additional: O99.21 Obesity complicating pregnancy, childbirth, and the puerperium ("code to identify the type of obesity (E66.-)")
• Type 1 Excludes: R63.5 Abnormal weight gain ("obesity (E66.-)")
• Code First: Z99.3 Dependence on wheelchair ("obesity (E66.-)")

Diagnosis Index entries for E66.2

• Obesity › with alveolar hypoventilation
• Obesity › hypoventilation syndrome (OHS)
• Obesity › morbid › with › alveolar hypoventilation
• Obesity › morbid › with › obesity hypoventilation syndrome (OHS)
• OHS (obesity hypoventilation syndrome)
• Pickwickian syndrome
• Syndrome › alveolar hypoventilation
• Syndrome › cardiopulmonary-obesity
• Syndrome › hypoventilation, obesity (OHS)
• Syndrome › obesity hypoventilation (OHS)
• Syndrome › Pickwickian

Nearby codes

• E66 Overweight and obesity
• E66.0 Obesity due to excess calories
• E66.01 Morbid (severe) obesity due to excess calories
• E66.09 Other obesity due to excess calories
• E66.1 Drug-induced obesity
• E66.2 Morbid (severe) obesity with alveolar hypoventilation (this code)
• E66.3 Overweight
• E66.8 Other obesity
• E66.81 Obesity class
• E66.811 Obesity, class 1
• E66.812 Obesity, class 2