Acute myocardial infarction
- I21 should not be used for reimbursement purposes as there are multiple codes below it that contain a greater level of detail.
- The 2025 edition of ICD-10-CM I21 became effective on October 1, 2024.
- This is the American ICD-10-CM version of I21 – other international versions of ICD-10 I21 may differ.
Use Additional
- 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.-)
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
The following code(s) above I21 contain annotation back-references
that may be applicable to I21:
Clinical Information
- A disorder characterized by gross necrosis of the myocardium; this is due to an interruption of blood supply to the area.
- Coagulation of blood in any of the coronary vessels. The presence of a blood clot (thrombus) often leads to myocardial infarction.
- Complete blockage of blood flow through one of the coronary arteries, usually from coronary atherosclerosis.
- Each year over a million people in the United States Have a heart attack. About half of them die. Many people have permanent heart damage or die because they don’t get help immediately. It’s important to know the symptoms of a heart attack and call 9-1-1 if someone is having them. Those symptoms include
- chest discomfort – pressure, squeezing, or pain
- shortness of breath
- discomfort in the upper body – arms, shoulder, neck, back
- nausea, vomiting, dizziness, lightheadedness, sweating
- Gross necrosis of the myocardium, as a result of interruption of the blood supply to the area, as in coronary thrombosis.
- Gross necrosis of the myocardium, as a result of interruption of the blood supply to the area.
- Necrosis of the myocardium caused by an obstruction of the blood supply to the heart (coronary circulation).
- Necrosis of the myocardium, as a result of interruption of the blood supply to the area. It is characterized by a severe and rapid onset of symptoms that may include chest pain, often radiating to the left arm and left side of the neck, dyspnea, sweating, and palpitations.
Code History
- 2016 (effective 10/1/2015): New code (first year of non-draft ICD-10-CM)
- 2017 (effective 10/1/2016): No change
- 2018 (effective 10/1/2017): Revised code
- New description: Acute myocardial infarction
- 2017 description: ST elevation (STEMI) and non-ST elevation (NSTEMI) myocardial infarction
- 2019 (effective 10/1/2018): No change
- 2020 (effective 10/1/2019): No change
- 2021 (effective 10/1/2020): No change
- 2022 (effective 10/1/2021): No change
- 2023 (effective 10/1/2022): No change
- 2024 (effective 10/1/2023): No change
- 2025 (effective 10/1/2024): No change
Code annotations containing back-references to I21: