ICD-10-CM 2027
ICD-10 code for hypertrophic obstructive myocardiopathy
From the official ICD-10-CM alphabetic index entry “Myocardiopathy (congestive) (constrictive) (familial) (hypertrophic nonobstructive) (idiopathic) (infiltrative) (obstructive) (primary) (restrictive) (sporadic) › hypertrophic obstructive”. Page updated September 29, 2026.
About coding hypertrophic obstructive myocardiopathy
The ICD-10-CM code for hypertrophic obstructive myocardiopathy is I42.1 (Obstructive hypertrophic cardiomyopathy).
Within I42 (cardiomyopathy), I42.1 is specifically for obstructive hypertrophic cardiomyopathy. Related codes cover dilated cardiomyopathy (I42.0), other hypertrophic cardiomyopathy (I42.2), Endomyocardial (eosinophilic) disease (I42.3), endocardial fibroelastosis (I42.4), other restrictive cardiomyopathy (I42.5), alcoholic cardiomyopathy (I42.6), due to drug and external agent (I42.7), other cardiomyopathies (I42.8) and 1 more.
Code first: pre-existing cardiomyopathy complicating pregnancy and puerperium (O99.4).
As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.
Common questions about hypertrophic obstructive myocardiopathy ICD-10 codes
What is the ICD-10 code for hypertrophic obstructive myocardiopathy?
- I42.1 — Obstructive hypertrophic cardiomyopathy.
Is I42.1 billable?
- Yes. I42.1 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can I42.1 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict I42.1 as a principal diagnosis.
Is I42.1 a CC or MCC?
- I42.1 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.