Table 1: Example of STEMI and NSTEMI Myocardial Infarction ICD-10 codes*
*Remember that these codes start with the letter I and not the number one (1).


I21 - Acute myocardial infarction

Including: MI specified as acute or with a stated duration of 4 weeks (28 days) or less from onset
Excluding: certain current complications following AMI (I23.-)
Myocardial infarction:

  • old (I25.2)
  • specified as chronic or with a stated duration of more than 4 weeks (more than 28 days) from onset (I25.8)
  • subsequent (I22.-) postmyocardial infarction syndrome (I24.1)

I21.0 – Acute transmural myocardial infarction of anterior wall

I21.01 St elevation (STEMI) myocardial infarction involving left main coronary artery

I21.02 St elevation (STEMI) myocardial infarction involving left anterior descending coronary artery

ST elevation (STEMI) MI involving diagonal coronary artery

I21.09 St elevation (STEMI) myocardial infarction involving other coronary artery of anterior wall

Acute transmural myocardial infarction of anterior wall
Anteroapical transmural (Q wave) infarction (acute)
Anterolateral transmural (Q wave) infarction (acute)
Anteroseptal transmural (Q wave) infarction (acute)
Transmural (Q wave) infarction (acute) (of) anterior (wall) NOS

I21.1 - Acute transmural myocardial infarction of inferior wall

I21.11 St elevation (STEMI) myocardial infarction involving right coronary artery

Inferoposterior transmural (Q wave) infarction (acute)

I21.19 St elevation (STEMI) myocardial infarction involving other coronary artery of inferior wall

Acute transmural myocardial infarction of inferior wall
Inferolateral transmural (Q wave) infarction (acute)
Transmural (Q wave) infarction (acute) (of) diaphragmatic wall
Transmural (Q wave) infarction (acute) (of) inferior (wall) NOS

Excludes: STEMI involving left circumflex coronary artery (I21.21)

I21.2 - Acute transmural myocardial infarction of other sites

I21.21 St elevation (STEMI) myocardial infarction involving left circumflex coronary artery

STEMI involving oblique marginal coronary artery

I21.29 St elevation (STEMI) myocardial infarction involving other sites

Acute transmural MI of other sites
Apical-lateral transmural (Q wave) infarction (acute)
Basal-lateral transmural (Q wave) infarction (acute)
High lateral transmural (Q wave) infarction (acute)
Lateral (wall) NOS transmural (Q wave) infarction (acute)
Posterior (true) transmural (Q wave) infarction (acute)
Posterobasal transmural (Q wave) infarction (acute)
Posterolateral transmural (Q wave) infarction (acute)
Posteroseptal transmural (Q wave) infarction (acute)
Septal transmural (Q wave) infarction (acute) NOS

I21.3 - Acute transmural myocardial infarction of unspecified site

Acute transmural MI of unspecified site
MI (acute) NOS
Transmural (Q wave) MI NOS

I21.4 - Acute subendocardial myocardial infarction

Acute subendocardial MI
Non-Q wave MI NOS
Nontransmural MI NOS

I21.9 - Acute myocardial infarction, unspecified

Myocardial infarction (acute) NOS