2025
ICD-10-CM
Diagnosis
Code

I21 Acute myocardial infarction

  • Non-billable
  • 2016–2025

I21 is a non-billable/non-specific diagnosis code from the 2025 ICD-10-CM used to classify the following condition: Acute myocardial infarction.

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

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)

Type 2 excludes

  • Old myocardial infarction (I25.2)

  • Postmyocardial infarction syndrome (I24.1)

  • Subsequent type 1 myocardial infarction (I22.-)

Codes

Versions

  1. 2025

    No changes

  2. 2024

    No changes

  3. 2023

    No changes

  4. 2022

    No changes

  5. 2021

    No changes

  6. 2020

    No changes

  7. 2019

    No changes

  8. 2018

    Code changed

    • Type 2 excludes

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

    • Description

        • ST elevation (STEMI) and non-ST elevation (NSTEMI) myocardial infarction
        • Acute myocardial infarction

    • Short description

        • STEMI & NSTEMI mocard infrc
        • Acute myocardial infarction

  9. 2017

    Code changed

    • Use additional code

        • code, if applicable, to identify:
        • exposure to environmental tobacco smoke (Z77.22)
        • history of tobacco use (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)
        • 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)

  10. 2016

    New code