I42.1 Obstructive hypertrophic cardiomyopathy
Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis.
Applicable to
- Hypertrophic subaortic stenosis (idiopathic)
Applies from I42 Cardiomyopathy
Includes
Excludes2 (not included here)
- ischemic cardiomyopathy (I25.5)
- peripartum cardiomyopathy (O90.3)
- ventricular hypertrophy (I51.7)
Code first
- pre-existing cardiomyopathy complicating pregnancy and puerperium (O99.4)
Risk adjustment (HCC)
- CMS-HCC V28: HCC 227 — Cardiomyopathy/Myocarditis
- CMS-HCC V22: HCC 85 — Congestive Heart Failure
- RxHCC V08: HCC 186 — Heart Failure
- ESRD V24: HCC 85
MS-DRG index
Defines the logic of DRG(s) 314-316 in MDC 05.
Approximate ICD-9-CM (GEMs)
425.11 Hypertrophic obstructive cardiomyopathy
Code annotations containing back-references to I42.1
Back-references to I42.1
- Code Also:
E74.05 Lysosome-associated membrane protein 2 [LAMP2] deficiency ("obstructive hypertrophic cardiomyopathy (I42.1)") - Type 2 Excludes:
I35 Nonrheumatic aortic valve disorders ("hypertrophic subaortic stenosis (I42.1)")
Back-references to I42
- Code First:
I5A Non-ischemic myocardial injury (non-traumatic) ("cardiomyopathy (I42.-)")
Diagnosis Index entries for I42.1
- Cardiomyopathy (familial) (idiopathic) › hypertrophic (nonobstructive) › obstructive
- Myocardiopathy (congestive) (constrictive) (familial) (hypertrophic nonobstructive) (idiopathic) (infiltrative) (obstructive) (primary) (restrictive) (sporadic) › hypertrophic obstructive
- Stenosis, stenotic (cicatricial) › hypertrophic subaortic (idiopathic)
- Stenosis, stenotic (cicatricial) › myocardium, myocardial › hypertrophic subaortic (idiopathic)
- Stenosis, stenotic (cicatricial) › subaortic (congenital) › hypertrophic (idiopathic)
- Stricture › myocardium, myocardial › hypertrophic subaortic (idiopathic)
- Stricture › subaortic › hypertrophic (acquired) (idiopathic)
Nearby codes
I42 CardiomyopathyI42.0 Dilated cardiomyopathyI42.1 Obstructive hypertrophic cardiomyopathy (this code)I42.2 Other hypertrophic cardiomyopathyI42.3 Endomyocardial (eosinophilic) diseaseI42.4 Endocardial fibroelastosisI42.5 Other restrictive cardiomyopathyI42.6 Alcoholic cardiomyopathy