2026 ICD-10-CM Diagnosis Code I20.81Angina pectoris with coronary microvascular dysfunction

ICD-10-CM Codes›I00–I99›I20-I25›I20

ICD-10-CM I20.81
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

I20.81 is a billable ICD-10-CM diagnosis code for angina pectoris with coronary microvascular dysfunction. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). Coders also document this condition as angina pectoris due to microvascular ischemia of myocardium. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Coronary atherosclerosis and other heart disease.

Code Identity

ICD-10-CM Code
I20.81
Billable Status
Yes — Valid for Submission
Code Describes
Angina pectoris with coronary microvascular dysfunction
Short Description
Angina pectoris with coronary microvascular dysfunction
Same as the full description in the CMS dataset.
Parent Code
I20.8
Other forms of angina pectoris

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI20-I25Ischemic heart diseases
CategoryI20Angina pectoris
This CodeI20.81Angina pectoris with coronary microvascular dysfunction

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Angina pectoris due to microvascular ischemia of myocardium
  • Cardiac syndrome X
  • Coronary microvascular dysfunction

Tabular List NotesGuidance

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

Inclusion Terms

  • Angina pectoris with coronary microvascular disease

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.

    • Angina(attack) (cardiac) (chest) (heart) (pectoris) (syndrome) (vasomotor)
      • with
        • coronary microvascular disease
    • Angina(attack) (cardiac) (chest) (heart) (pectoris) (syndrome) (vasomotor)
      • with
        • coronary microvascular dysfunction
    • Disease, diseased
      • coronary (artery)
        • microvascular
          • with
            • angina pectoris
    • Dysfunction
      • coronary microvascular
        • with
          • angina pectoris

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

Angina

Angina is chest pain or discomfort you feel when there is not enough blood flow to your heart muscle. Your heart muscle needs the oxygen that the blood carries. Angina may feel like pressure or a squeezing pain in your chest. It may feel like indigestion. You may also feel pain in your shoulders, arms, neck, jaw, or back.

Read the full article at MedlinePlus

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

Code History & ChangesHistory

Replacement I20.81 replaces the following previously assigned code(s):

  • I20.8 - Other forms of angina pectoris
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 I20.81Overview

Is I20.81 (Other forms of angina pectoris) a billable code?

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

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.