2026 ICD-10-CM Diagnosis Code I42.7Cardiomyopathy due to drug and external agent

ICD-10-CM Codes›I00–I99›I30-I5A›I42

ICD-10-CM I42.7
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

I42.7 is a billable ICD-10-CM diagnosis code for cardiomyopathy due to drug and external agent. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 314 through 316. Coders also document this condition as cardiomyopathy caused by drug. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Drug induced or toxic related condition and Myocarditis and cardiomyopathy.

Code Identity

ICD-10-CM Code
I42.7
Billable Status
Yes — Valid for Submission
Code Describes
Cardiomyopathy due to drug and external agent
Short Description
Cardiomyopathy due to drug and external agent
Same as the full description in the CMS dataset.
Parent Code
I42
Cardiomyopathy

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI30-I5AOther forms of heart disease
CategoryI42Cardiomyopathy
This CodeI42.7Cardiomyopathy due to drug and external agent

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Cardiomyopathy caused by drug
  • Chronic myocardial disorder caused by chemical or external agent
  • Cobalt cardiomyopathy
  • Dilated cardiomyopathy caused by drug
  • Toxic cardiomyopathy
  • Toxic dilated cardiomyopathy

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Code First

  • poisoning due to drug or toxin, if applicable T36 T65

Use Additional Code

  • code for adverse effect, if applicable, to identify drug T36 T50

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Cardiomyopathy(familial) (idiopathic)
      • due to
        • drugs
    • Cardiomyopathy(familial) (idiopathic)
      • due to
        • external agents NEC
    • Cardiomyopathy(familial) (idiopathic)
      • toxic NEC
    • Myocardiopathy(congestive) (constrictive) (familial) (hypertrophic nonobstructive) (idiopathic) (infiltrative) (obstructive) (primary) (restrictive) (sporadic)
      • toxic NEC

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INJ030
Drug induced or toxic related condition
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR CIR005
Myocarditis and cardiomyopathy
Default principal diagnosis: inpatient No · outpatient No

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.

Convert I42.7 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
425.9 Second cardiomyopath NOS
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About I42.7Overview

Is I42.7 (Cardiomyopathy) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report cardiomyopathy due to drug and external agent on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does I42.7 group to?

When cardiomyopathy due to drug and external agent is the principal diagnosis on an inpatient stay, it groups to MS-DRG 314, 315, 316, with relative weights from 0.6821 to 2.0852 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of I42.7?

Under the General Equivalence Mappings, cardiomyopathy due to drug and external agent converts to ICD-9-CM 425.9 (second cardiomyopath NOS). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.