2027 ICD-10-CM Diagnosis Code I23Certain current complications following ST elevation (STEMI) and non-ST elevation (NSTEMI) myocardial infarction (within the 28 day period)

ICD-10-CM Codes›I00–I99›I20-I25›STEMI

ICD-10-CM I23
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

I23 is a non-billable ICD-10-CM category code for certain current complications following ST elevation (STEMI) and non-ST elevation (NSTEMI) myocardial infarction (within the 28 day period), so it cannot be submitted on claims. Use a more specific code from this category instead, such as I23.0, I23.1, I23.2, and I23.3.

Code Identity

ICD-10-CM Code
I23
Billable Status
No — Non-Billable Category
Code Describes
Certain current complications following ST elevation (STEMI) and non-ST elevation (NSTEMI) myocardial infarction (within the 28 day period)
Short Description
Certain crnt comp fol STEMI & NSTEMI mocard infrc <= 28 day
Chapter
I20-I25
Ischemic heart diseases

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI20-I25Ischemic heart diseases
CategorySTEMICertain current complications following ST elevation and non-ST elevation (NSTEMI) myocardial infarction (within the 28 day period) (I23)
This CodeI23Certain current complications following ST elevation (STEMI) and non-ST elevation (NSTEMI) myocardial infarction (within the 28 day period)

Specific Coding for Certain crnt comp fol STEMI & NSTEMI mocard infrc <= 28 dayOverview

Non-specific codes like I23 require more characters. Use one of these billable codes instead:

  • Use I23.0 for Hemopericardium as current complication following acute myocardial infarction

  • Use I23.1 for Atrial septal defect as current complication following acute myocardial infarction

  • Use I23.2 for Ventricular septal defect as current complication following acute myocardial infarction

  • Use I23.3 for Rupture of cardiac wall without hemopericardium as current complication following acute myocardial infarction

  • Use I23.4 for Rupture of chordae tendineae as current complication following acute myocardial infarction

  • Use I23.5 for Rupture of papillary muscle as current complication following acute myocardial infarction

  • Use I23.6 for Thrombosis of atrium, auricular appendage, and ventricle as current complications following acute myocardial infarction

  • Use I23.7 for Postinfarction angina

  • Use I23.8 for Other current complications following acute myocardial infarction

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to I23: its own notes plus those printed at block I20-I25 and Chapter 9. A note printed at a category, block or chapter applies to every code under it.

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Chapter 9 (I00-I99) Diseases of the circulatory system applies to 1,433 codes
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
  • systemic connective tissue disorders (M30-M36)
  • transient cerebral ischemic attacks and related syndromes (G45.-)

Code Also

A second code may be needed to fully describe the condition; the note gives no sequencing direction.

From Block I20-I25 Ischemic heart diseases applies to 94 codes
  • the presence of hypertension (I10-I1A)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name I23, its category, or a range that includes it.

Excludes2 2

These codes carry an Excludes2 note naming I23: its condition is not part of those codes, and both may be reported when the patient has both.

  • I74 Arterial embolism and thrombosis
    coronary embolism and thrombosis (I21-I25) names I21-I25, which includes this code
  • I82 Other venous embolism and thrombosis
    coronary (I21-I25) names I21-I25, which includes this code

Patient EducationClinical

Heart Attack

A heart attack, also called a myocardial infarction, is a type of heart disease. It happens when blood flow to the heart suddenly becomes blocked. Without the blood coming in, the heart can't get oxygen. If not treated quickly, the heart muscle begins to die.

The full article covers:

  • What is a heart attack?
  • What heart attack risk factors can be changed?
  • What heart attack risk factors can't be changed?
  • What causes a heart attack?
  • What are the symptoms of a heart attack?
  • How is a heart attack diagnosed?
  • What is the treatment for a heart attack?

Read the full article at MedlinePlus

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

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About I23Overview

Is I23 a billable code?

No. This is a category header that groups the codes for certain current complications following ST elevation (STEMI) and non-ST elevation (NSTEMI) myocardial infarction (within the 28 day period), and headers cannot be submitted on claims. Claims for certain current complications following ST elevation (STEMI) and non-ST elevation (NSTEMI) myocardial infarction (within the 28 day period) need a more specific code from this category, such as I23.0, I23.1, and I23.2.