2027 ICD-10-CM Diagnosis Code I42Cardiomyopathy

ICD-10-CM Codes›I00–I99›I30-I5A›I42

ICD-10-CM I42
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

I42 is a non-billable ICD-10-CM category code for cardiomyopathy, so it cannot be submitted on claims. Use a more specific code from this category instead, such as I42.00, I42.01, I42.09, and I42.1.

Code Identity

ICD-10-CM Code
I42
Billable Status
No — Non-Billable Category
Code Describes
Cardiomyopathy
Short Description
Cardiomyopathy
Same as the full description in the CMS dataset.
Chapter
I30-I5A
Other forms of heart disease

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI30-I5AOther forms of heart disease
CategoryI42Cardiomyopathy
This CodeI42Cardiomyopathy

Specific Coding for CardiomyopathyOverview

Non-specific codes like I42 require more characters. Use one of these billable codes instead:

  • I42.0 for Dilated cardiomyopathy

  • Use I42.00 for Dilated cardiomyopathy, unspecified

  • Use I42.01 for Familial-genetic dilated cardiomyopathy

  • Use I42.09 for Other dilated cardiomyopathy

  • Use I42.1 for Obstructive hypertrophic cardiomyopathy

  • Use I42.2 for Other hypertrophic cardiomyopathy

  • Use I42.3 for Endomyocardial (eosinophilic) disease

  • Use I42.4 for Endocardial fibroelastosis

  • Use I42.5 for Other restrictive cardiomyopathy

  • Use I42.6 for Alcoholic cardiomyopathy

  • Use I42.7 for Cardiomyopathy due to drug and external agent

  • I42.8 for Other cardiomyopathies

  • Use I42.81 for Arrhythmogenic cardiomyopathy

  • Use I42.89 for Other cardiomyopathies not elsewhere classified

  • Use I42.9 for Cardiomyopathy, unspecified

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to I42: its own notes plus those printed at Chapter 9. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

  • myocardiopathy

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

On I42 itself
  • ischemic cardiomyopathy (I25.5)
  • peripartum cardiomyopathy (O90.3)
  • ventricular hypertrophy (I51.7)
From Chapter 9 (I00-I99) Diseases of the circulatory system applies to 1,433 codes
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
  • systemic connective tissue disorders (M30-M36)
  • transient cerebral ischemic attacks and related syndromes (G45.-)

Code First

The underlying condition named in the note is sequenced before this code.

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

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name I42, its category, or a range that includes it.

Applicable To 1

These notes mention I42.

  • O90.3 Peripartum cardiomyopathy
    Conditions in I42.- arising during pregnancy and the puerperium

Code First 1

These codes say to code first a condition named in the note, and I42 is one of the conditions named.

  • I5A Non-ischemic myocardial injury (non-traumatic)
    cardiomyopathy (I42.-)

Clinical InformationClinical

  • Cardiomyopathies

    a group of diseases in which the dominant feature is the involvement of the cardiac muscle itself. cardiomyopathies are classified according to their predominant pathophysiological features (dilated cardiomyopathy; hypertrophic cardiomyopathy; restrictive cardiomyopathy) or their etiological/pathological factors (cardiomyopathy, alcoholic; endocardial fibroelastosis).

Patient EducationClinical

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 the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About I42Overview

What is the ICD-10 code for cardiomyopathy?

I42 is the ICD-10-CM category for cardiomyopathy, but it is a non-billable header: claims need a more specific code from this category, listed on this page.

Is I42 (Cardiomyopathy) a billable code?

No. This is a category header that groups the codes for cardiomyopathy, and headers cannot be submitted on claims. Claims for cardiomyopathy need a more specific code from this category, such as I42.00, I42.01, and I42.09.

What is coded first with I42?

The Code First note reads: pre-existing cardiomyopathy complicating pregnancy and puerperium (O99.4). When one of these applies, it is sequenced before I42.