`I42.4` Endocardial fibroelastosis

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

Applicable to

Congenital cardiomyopathy
Elastomyofibrosis

Applies from I42 Cardiomyopathy

Includes

myocardiopathy

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)

425.3 Endocardial fibroelastosis

Code annotations containing back-references to I42.4

Back-references to I42.4

Type 1 Excludes: I38 Endocarditis, valve unspecified ("endocardial fibroelastosis (I42.4)")
Type 1 Excludes: Q24 Other congenital malformations of heart ("endocardial fibroelastosis (I42.4)")

Back-references to I42

Code First: I5A Non-ischemic myocardial injury (non-traumatic) ("cardiomyopathy (I42.-)")

Diagnosis Index entries for I42.4

Anomaly, anomalous (congenital) (unspecified type) › heart › fibroelastosis cordis
Cardiomyopathy (familial) (idiopathic) › congenital
Cardiomyopathy (familial) (idiopathic) › newborn › congenital
Elastomyofibrosis
Fibroelastosis (cordis) (endocardial) (endomyocardial)
Newborn (infant) (liveborn) (singleton) › affected by › cardiomyopathy › congenital
Sclerosis, sclerotic › subendocardial, congenital

Nearby codes

I42 Cardiomyopathy
I42.0 Dilated cardiomyopathy
I42.1 Obstructive hypertrophic cardiomyopathy
I42.2 Other hypertrophic cardiomyopathy
I42.3 Endomyocardial (eosinophilic) disease
I42.4 Endocardial fibroelastosis (this code)
I42.5 Other restrictive cardiomyopathy
I42.6 Alcoholic cardiomyopathy
I42.7 Cardiomyopathy due to drug and external agent
I42.8 Other cardiomyopathies
I42.9 Cardiomyopathy, unspecified