I27.21 Secondary pulmonary arterial hypertension

Billable ICD-10-CM code, FY2026.

Applicable to

• (Associated) (drug-induced) (toxin-induced) pulmonary arterial hypertension NOS
• (Associated) (drug-induced) (toxin-induced) (secondary) group 1 pulmonary hypertension

Code also

• associated conditions if applicable, or adverse effects of drugs or toxins, such as:
• adverse effect of appetite depressants (T50.5X5)
• congenital heart disease (Q20-Q28)
• human immunodeficiency virus [HIV] disease (B20)
• polymyositis (M33.2-)
• portal hypertension (K76.6)
• rheumatoid arthritis (M05.-)
• schistosomiasis (B65.-)
• Sjögren syndrome (M35.0-)
• systemic sclerosis (M34.-)

Applies from I27.2 Other secondary pulmonary hypertension

Excludes1 (never code together)

• Eisenmenger's syndrome (I27.83)

Code also

• associated underlying condition

Risk adjustment (HCC)

• CMS-HCC V28: HCC 226 — Heart Failure, Except End-Stage and Acute
• CMS-HCC V22: HCC 85 — Congestive Heart Failure
• RxHCC V08: HCC 183 — Pulmonary Arterial Hypertension
• ESRD V24: HCC 85

MS-DRG index

Defines the logic of DRG(s) 314-316 in MDC 05.

Approximate ICD-9-CM (GEMs)

• 416.8 Other chronic pulmonary heart diseases (approximate)

Code annotations containing back-references to I27.21

Back-references to I27.21

• Type 1 Excludes: I27.0 Primary pulmonary hypertension ("secondary pulmonary arterial hypertension (I27.21)")
• Code Also: M34.81 Systemic sclerosis with lung involvement ("secondary pulmonary arterial hypertension (I27.21)")

Back-references to I27.2

• Code First: I5A Non-ischemic myocardial injury (non-traumatic) ("pulmonary hypertension (I27.0, I27.2-)")
• Use Additional: P24.01 Meconium aspiration with respiratory symptoms ("code to identify any secondary pulmonary hypertension, if applicable (I27.2-)")
• Use Additional: P24.11 Neonatal aspiration of (clear) amniotic fluid and mucus with respiratory symptoms ("code to identify any secondary pulmonary hypertension, if applicable (I27.2-)")
• Use Additional: P24.21 Neonatal aspiration of blood with respiratory symptoms ("code to identify any secondary pulmonary hypertension, if applicable (I27.2-)")
• Use Additional: P24.31 Neonatal aspiration of milk and regurgitated food with respiratory symptoms ("code to identify any secondary pulmonary hypertension, if applicable (I27.2-)")
• Use Additional: P24.81 Other neonatal aspiration with respiratory symptoms ("code to identify any secondary pulmonary hypertension, if applicable (I27.2-)")

Diagnosis Index entries for I27.21

• Hypertension, hypertensive (accelerated) (benign) (essential) (idiopathic) (malignant) (systemic) › pulmonary › arterial (associated) (drug-induced) (toxin-induced)
• Hypertension, hypertensive (accelerated) (benign) (essential) (idiopathic) (malignant) (systemic) › pulmonary › group 1 (associated) (drug-induced) (toxin-induced)
• Hypertension, hypertensive (accelerated) (benign) (essential) (idiopathic) (malignant) (systemic) › pulmonary › secondary › arterial

Nearby codes

• I27 Other pulmonary heart diseases
• I27.0 Primary pulmonary hypertension
• I27.1 Kyphoscoliotic heart disease
• I27.2 Other secondary pulmonary hypertension
• I27.20 Pulmonary hypertension, unspecified
• I27.21 Secondary pulmonary arterial hypertension (this code)
• I27.22 Pulmonary hypertension due to left heart disease
• I27.23 Pulmonary hypertension due to lung diseases and hypoxia
• I27.24 Chronic thromboembolic pulmonary hypertension
• I27.29 Other secondary pulmonary hypertension
• I27.8 Other specified pulmonary heart diseases