Is ICD-10-CM code I42.81 billable?

Yes, I42.81 (Arrhythmogenic cardiomyopathy) is a billable ICD-10-CM diagnosis code, valid for reimbursement on HIPAA-covered transactions for FY2027.

What chapter does ICD-10-CM code I42.81 belong to?

I42.81 belongs to Chapter 9 of the ICD-10-CM tabular list: I00–I99 (Diseases of the Circulatory System).

Is I42.81 a new ICD-10-CM code for 2027?

Yes, I42.81 was added or revised in the FY2027 ICD-10-CM update, effective October 1, 2026, as published by the Centers for Medicare and Medicaid Services (CMS).

I42.81BillableCCNew for FY2027

Arrhythmogenic cardiomyopathy

Diseases of the Circulatory System·Other cardiomyopathies·subcategory·FY 2027

Cardiomyopathy: Cardiomyopathy is the name for diseases of the heart muscle. These diseases enlarge your heart muscle or make it thicker and more rigid than normal. In rare cases, scar tissue replaces the muscle tissue.

Read more about cardiomyopathy on MedlinePlus · Source: MedlinePlus, National Library of Medicine

Also indexed as: Cardiomyopathy, arrhythmogenic; Cardiomyopathy, arrhythmogenic, biventricular; Cardiomyopathy, arrhythmogenic, ventricular; Dysplasia, arrhythmogenic right ventricular; Dysplasia, right ventricular, arrhythmogenic; Dysplasia, ventricular, arrhythmogenic

Instructional notes

Also applies, from I42: Cardiomyopathy

These notes sit on I42 and apply to every code under it, including I42.81.

Includes: conditions that are coded here

myocardiopathy

Excludes2: not included here, code separately if applicable

ischemic cardiomyopathy (I25.5)
peripartum cardiomyopathy (O90.3)
ventricular hypertrophy (I51.7)

Code first: code the underlying condition first, then this code

pre-existing cardiomyopathy complicating pregnancy and puerperium (O99.4)

Where I42.81 sits

I30-I5A Other forms of heart disease (I30-I5A)
I42 Cardiomyopathy
I42.8 Other cardiomyopathies
I42.81 Arrhythmogenic cardiomyopathy

MS-DRGs

As the principal diagnosis, this code groups to these MS-DRGs (v44.0). Which one applies depends on procedures performed, secondary diagnoses (CC/MCC), and the patient's age and discharge status.

Code history

FY 2026: replaced I42.8 (Other cardiomyopathies)