2026 ICD-10-CM Diagnosis Code I25.42Coronary artery dissection

ICD-10-CM Codes›I00–I99›I20-I25›I25

ICD-10-CM I25.42
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

I25.42 is a billable ICD-10-CM diagnosis code for coronary artery dissection. 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 acute dissection of coronary artery. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Arterial dissections.

This medical diagnosis code is frequently used in Cardiology medical specialties to designate conditions such selected atherosclerosis, ischemia, and infarction.

Code Identity

ICD-10-CM Code
I25.42
Billable Status
Yes — Valid for Submission
Code Describes
Coronary artery dissection
Short Description
Coronary artery dissection
Same as the full description in the CMS dataset.
Parent Code
I25.4
Coronary artery aneurysm and dissection

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI20-I25Ischemic heart diseases
CategoryI25Chronic ischemic heart disease
This CodeI25.42Coronary artery dissection

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Acute dissection of coronary artery
  • Chronic dissection of coronary artery
  • Dissection of anterior descending branch of left coronary artery
  • Dissection of coronary artery
  • Idiopathic spontaneous coronary artery dissection

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.

    • Dissection
      • artery
        • coronary

Clinical ClassificationClinical

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

CCSR CIR027
Arterial dissections
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Coronary Artery Disease

Coronary artery disease (CAD) is the most common type of heart disease. It is the leading cause of death in the United States in both men and women.

Read the full article at MedlinePlus

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

Convert I25.42 to ICD-9-CMHistory

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

ICD-9-CM
414.12 Dissection cor artery
Exact Match The mapping is direct, with no qualifiers.

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 I25.42Overview

Is I25.42 (Coronary artery aneurysm and dissection) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report coronary artery dissection on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does I25.42 group to?

When coronary artery dissection 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 I25.42?

Under the General Equivalence Mappings, coronary artery dissection converts to ICD-9-CM 414.12 (dissection cor artery). The mapping is a direct match.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.