2026 ICD-10-CM Diagnosis Code I25.85Chronic coronary microvascular dysfunction

ICD-10-CM Codes›I00–I99›I20-I25›I25

ICD-10-CM I25.85
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

I25.85 is a billable ICD-10-CM diagnosis code for chronic coronary microvascular dysfunction. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 302 through 303. Coders also document this condition as chronic ischemic heart disease. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Coronary atherosclerosis and other heart disease.

Code Identity

ICD-10-CM Code
I25.85
Billable Status
Yes — Valid for Submission
Code Describes
Chronic coronary microvascular dysfunction
Short Description
Chronic coronary microvascular dysfunction
Same as the full description in the CMS dataset.
Parent Code
I25.8
Other forms of chronic ischemic heart disease

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI20-I25Ischemic heart diseases
CategoryI25Chronic ischemic heart disease
This CodeI25.85Chronic coronary microvascular dysfunction

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Chronic ischemic heart disease
  • Chronic microvascular ischemia of myocardium
  • Chronic myocardial ischemia
  • Coronary microvascular dysfunction

Tabular List NotesGuidance

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

Inclusion Terms

  • Chronic (presentation of) coronary microvascular disease
  • Coronary microvascular dysfunction NOS

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.

    • Disease, diseased
      • coronary (artery)
        • microvascular
          • chronic
    • Dysfunction
      • chronic
        • coronary microvascular
    • Dysfunction
      • coronary microvascular
    • Dysfunction
      • coronary microvascular
        • chronic

Clinical ClassificationClinical

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

CCSR CIR011
Coronary atherosclerosis and other heart disease
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Heart Diseases

Heart disease is a general term that includes many types of heart problems. It's a type of cardiovascular disease, which means heart and blood vessel disease.

The full article covers:

  • What is heart disease?
  • What are the types of heart disease?
  • What causes heart diseases?
  • Who is more likely to develop heart diseases?
  • What are the symptoms of heart disease?
  • How are heart diseases diagnosed?
  • What are the treatments for heart disease?
  • Can heart diseases be prevented?

Read the full article at MedlinePlus

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

Code History & ChangesHistory

Replacement I25.85 replaces the following previously assigned code(s):

  • I25.89 - Other forms of chronic ischemic heart disease
FY 2024AddedAdded to the ICD-10-CM code setEffective October 1, 2023.
FY 2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About I25.85Overview

Is I25.85 (Other forms of chronic ischemic heart disease) a billable code?

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

What MS-DRG does I25.85 group to?

When chronic coronary microvascular dysfunction is the principal diagnosis on an inpatient stay, it groups to MS-DRG 302, 303, with relative weights from 0.6732 to 1.1966 depending on complications. Higher weights mean higher Medicare reimbursement.

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.