ICD-10-CM 2027
ICD-10 code for secondary cardiomyopathy
From the official ICD-10-CM alphabetic index entry “Cardiomyopathy (familial) (idiopathic) › secondary”. Page updated September 29, 2026.
About coding secondary cardiomyopathy
The ICD-10-CM code for secondary cardiomyopathy is I42.9 (Cardiomyopathy, unspecified).
Within I42, choose I42.9 (unspecified) only when documentation doesn't support a more specific option: dilated cardiomyopathy (I42.0), obstructive hypertrophic cardiomyopathy (I42.1), 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) 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 secondary cardiomyopathy ICD-10 codes
What is the ICD-10 code for secondary cardiomyopathy?
- I42.9 — Cardiomyopathy, unspecified.
Is I42.9 billable?
- Yes. I42.9 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can I42.9 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict I42.9 as a principal diagnosis.
Is I42.9 a CC or MCC?
- I42.9 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.