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ICD-10-CM 2027 diagnosis code

I42.0Dilated cardiomyopathy

Not billable — use a more specific code

I42.0 is a header code, so it can't be reported by itself. Choose one of the 3 more specific codes beneath it.

Code last changed in FY2027 (effective October 1, 2026). Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About I42.0

I42.0 is the ICD-10-CM diagnosis code for dilated cardiomyopathy. It belongs to category I42 (cardiomyopathy), block I30-I5A (other forms of heart disease) and chapter 9 (diseases of the circulatory system). It is a header code, so it can't be reported by itself; one of its 3 subcodes must be used instead.

Within I42 (cardiomyopathy), I42.0 is specifically for dilated cardiomyopathy. Related codes cover 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), other cardiomyopathies (I42.8) and 1 more.

To report this condition, pick the subcode that matches the documentation: I42.00 (unspecified), I42.01 (cardiomyopathy) and I42.09 (cardiomyopathy).

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

It has been part of ICD-10-CM since the code set took effect on October 1, 2015, and changed in FY2027 (expanded into subcodes).

Before ICD-10, this condition was coded in ICD-9-CM as 425.4 (other primary cardiomyopathies).

Specific codes under I42.0

Notes that apply from higher levels

Instructions written at a parent level also apply to I42.0.

› From I42 Cardiomyopathy
Includes
  • myocardiopathy
Excludes2
  • ischemic cardiomyopathy (I25.5)
  • peripartum cardiomyopathy (O90.3)
  • ventricular hypertrophy (I51.7)
Code first
  • pre-existing cardiomyopathy complicating pregnancy and puerperium (O99.4)

Broader instructions also apply from Chapter 9: Diseases of the circulatory system.

Codes whose notes reference I42.0

ICD-9-CM equivalent

Converter →
  • 425.4Other primary cardiomyopathiesapproximate

From the CMS 2018 General Equivalence Mappings (GEMs), the final GEMs release.

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
  • FY2027 (effective 10/1/2026): Expanded — no longer billable

Common questions about I42.0

Is I42.0 billable?

No. I42.0 is a header code. Report one of its more specific subcodes instead.

What is the ICD-9 code for I42.0?

The CMS General Equivalence Mappings map I42.0 to ICD-9-CM 425.4.

Did I42.0 change for 2027?

Yes. For FY2027 (effective October 1, 2026) it was expanded into more specific subcodes, so it is no longer billable.