2026 ICD-10-CM Diagnosis Code I24.9Acute ischemic heart disease, unspecified
ICD-10-CM Codes›I00–I99›I20-I25›I24
- Billable — Valid for Submission
- Chronic Condition
I24.9 is a billable ICD-10-CM diagnosis code for acute ischemic heart disease, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). Coders also document this condition as acute coronary syndrome. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Coronary atherosclerosis and other heart disease.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Acute coronary syndrome
- Acute ischemic heart disease
- Acute myocardial ischemia
- Erythrocytosis due to cardiovascular disease
- Erythrocytosis due to tissue hypoxemia
- Polycythemia due to cyanotic heart disease
- Subacute ischemic heart disease
- Transient myocardial ischemia
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Type 1 Excludes
- ischemic heart disease chronic NOS I25.9
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Index to Diseases and InjuriesGuidance
External Cause of Injuries IndexGuidance
References for this code in the External Cause of Injuries Index.
- Cyanotic heart disease
- Ischemia, ischemic
- heart (chronic or with a stated duration of over 4 weeks)
- acute or with a stated duration of 4 weeks or less
- Ischemia, ischemic
- heart (chronic or with a stated duration of over 4 weeks)
- subacute
- Syndrome
- coronary
- acute NEC
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Acute Coronary Syndrome
an episode of myocardial ischemia that generally lasts longer than a transient anginal episode that ultimately may lead to myocardial infarction.
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 I24.9 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About I24.9Overview
Is I24.9 (Other acute ischemic heart diseases) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report acute ischemic heart disease, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What is the ICD-9 equivalent of I24.9?
Under the General Equivalence Mappings, acute ischemic heart disease, unspecified converts to ICD-9-CM 411.89 (ac ischemic hrt dis NEC). The mapping is approximate, so confirm the match fits the documentation.
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.
