I21
⚠ Non-billable (Header)Acute myocardial infarction
Diseases of the circulatory system (I00-I99)
⚠️ This is a category header code — not billable. Use a more specific child code below.
✅ 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
📋 Code Instructions
- • 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)
⚠️ Excludes2
directMay be coded together if both conditions coexist
- • old myocardial infarction (I25.2)
- • postmyocardial infarction syndrome (I24.1)
- • subsequent type 1 myocardial infarction (I22.-)
Child Codes (8)
I21.0ST elevation (STEMI) myocardial infarction of anterior wallI21.1ST elevation (STEMI) myocardial infarction of inferior wallI21.2ST elevation (STEMI) myocardial infarction of other sitesI21.3ST elevation (STEMI) myocardial infarction of unspecified siteI21.4Non-ST elevation (NSTEMI) myocardial infarctionI21.9Acute myocardial infarction, unspecifiedI21.AOther type of myocardial infarctionI21.BMyocardial infarction with coronary microvascular dysfunction
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CodeI21
BillableNo — Header code
CategoryDiseases of the circulatory system (I00-I99)
Excludes10 rule(s)
Excludes23 note(s)
Child codes8
Data Source
CMS ICD-10-CM 2026 Tabular List
Updated October 1, 2025 (FY2026)