ICD-10-CM › I00-I99 › I20-I25 › I codes › I21

I21

Acute myocardial infarction

Not billableICD-10-CM diagnosis code.

This code exists but cannot be submitted on its own. It groups the more specific codes beneath it.

A category header for its whole life, FY2016 onwards. It has never been valid for submission on its own.

Submit one of these 8 more specific codes instead:

  • I21.0 ST elevation (STEMI) myocardial infarction of anterior wall (also a header)
  • I21.1 ST elevation (STEMI) myocardial infarction of inferior wall (also a header)
  • I21.2 ST elevation (STEMI) myocardial infarction of other sites (also a header)
  • I21.3 ST elevation (STEMI) myocardial infarction of unspecified site
  • I21.4 Non-ST elevation (NSTEMI) myocardial infarction
  • I21.9 Acute myocardial infarction, unspecified
  • I21.A Other type of myocardial infarction (also a header)
  • I21.B Myocardial infarction with coronary microvascular dysfunction

What has happened to this code

Every change the publisher made, from 2012 to now. Entries marked draft are from the pre-implementation releases: ICD-10 took effect on 1 October 2015, so nothing before FY2016 was ever valid on a claim.

  1. FY2012 Added to the draft code set draft ST elevation (STEMI) and non-ST elevation (NSTEMI) myocardial infarction
  2. FY2018 Description revised ST elevation (STEMI) and non-ST elevation (NSTEMI) myocardial infarction Acute myocardial infarction

Official coding rules

Published by CDC for FY2027. A rule attached to a category binds every code beneath it, so the rules inherited from this code's ancestors are shown with the code they come from.

This code

Excludes2 - not included here

  • old myocardial infarction (I25.2)
  • postmyocardial infarction syndrome (I24.1)
  • subsequent type 1 myocardial infarction (I22.-)

Use additional code

  • code, if applicable, to identify:
  • exposure to environmental tobacco smoke (Z77.22)
  • history of tobacco dependence (Z87.891)
  • occupational exposure to environmental tobacco smoke (Z57.31)
  • status post administration of tPA (rtPA) in a different facility within the last 24 hours prior to admission to current facility (Z92.82)
  • tobacco dependence (F17.-)
  • tobacco use (Z72.0)

Includes

  • cardiac infarction
  • coronary (artery) embolism
  • coronary (artery) occlusion
  • coronary (artery) rupture
  • coronary (artery) thrombosis
  • infarction of heart, myocardium, or ventricle
  • myocardial infarction specified as acute or with a stated duration of 4 weeks (28 days) or less from onset

Inherited from the I20-I25 section Ischemic heart diseases (I20-I25)

Code also

  • the presence of hypertension (I10-I1A)