Is ICD-10-CM code I24 billable?

No, I24 (Other acute ischemic heart diseases) is a non-billable ICD-10-CM code. It must be coded to a more specific subcategory before it can be used for reimbursement.

What chapter does ICD-10-CM code I24 belong to?

I24 belongs to Chapter 9 of the ICD-10-CM tabular list: I00–I99 (Diseases of the Circulatory System).

I24Not billable, use a more specific code below

Other acute ischemic heart diseases

In Ischemic heart diseases (I20-I25), chapter 9: Diseases of the Circulatory System

5 billable codes under I24: all are a CC; all map to HCC 229 (Unstable Angina and Other Acute Ischemic Heart Disease).A CC or MCC (major CC) is a secondary diagnosis that raises the MS-DRG payment. An HCC counts toward a Medicare Advantage patient's risk score.

Instructional notes

Excludes1: not coded here, use a different code

angina pectoris (I20.-)
transient myocardial ischemia in newborn (P29.4)

Excludes2: not included here, code separately if applicable

non-ischemic myocardial injury (I5A)

Also applies, from Ischemic heart diseases (I20-I25)

These notes sit on I20-I25 and apply to every code under it, including I24.

Code also: add a code for this too, order depends on the encounter

the presence of hypertension (I10-I1A)

Official coding guidelines

From the ICD-10-CM Official Guidelines for Coding and Reporting, FY 2027 (CMS and NCHS). Links open the PDF at the right page.

Covers hypertension with heart and kidney disease, coronary artery disease with angina, perioperative stroke, cerebrovascular sequelae, and acute myocardial infarction types and timing.

Hypertension (page 50)
Atherosclerotic Coronary Artery Disease and Angina (page 52)
Intraoperative and Postprocedural Cerebrovascular Accident (page 53)
Sequelae of Cerebrovascular Disease (page 53)
Acute myocardial infarction (AMI) (page 54)

Read Section I.C.9 (page 50)

All codes under I24

I24 can't be used on a claim. Pick a billable code below; grey headings group them.

I24 MS-DRGs

As the principal diagnosis, the billable codes under I24 group to MS-DRG 311, 314, 315, or 316 (v44.0). Which one applies depends on procedures performed, secondary diagnoses (CC/MCC), and the patient's age and discharge status.

DRG 311 Angina Pectoris (4 of 5 codes)
DRG 314 Other Circulatory System Diagnoses with MCC (1 of 5 codes)
DRG 315 Other Circulatory System Diagnoses with CC (1 of 5 codes)
DRG 316 Other Circulatory System Diagnoses without CC/MCC (1 of 5 codes)

Other codes that refer to I24

Notes on these codes point to I24.

I5A Excludes2: other acute ischemic heart diseases (I24.-)

About the condition

Plain-language background from MedlinePlus (National Library of Medicine), not coding guidance.

Coronary Artery Disease

Coronary artery disease (CAD) is the most common type of heart disease in the United States and a leading cause of death for both men and women. CAD affects the coronary arteries, which are the blood vessels that carry blood and oxygen to your heart muscle. When these arteries are damaged or diseased, your heart does not get the blood it needs.

Code history

Valid since FY2016, when ICD-10-CM took effect on October 1, 2015. No changes since.