Version 2024

2024 ICD-10-CM Diagnosis Code I21

Acute myocardial infarction

ICD-10-CM Code:
I21
ICD-10 Code for:
Acute myocardial infarction
Is Billable?
Not Valid for Submission
Code Navigator:

Code Classification

  • Diseases of the circulatory system
    (I00–I99)
    • Ischemic heart diseases
      (I20-I25)
      • Acute myocardial infarction
        (I21)

I21 is a non-specific and non-billable diagnosis code code, consider using a code with a higher level of specificity for a diagnosis of acute myocardial infarction. The code is not specific and is NOT valid for the year 2024 for the submission of HIPAA-covered transactions. Category or Header define the heading of a category of codes that may be further subdivided by the use of 4th, 5th, 6th or 7th characters.

Specific Coding Applicable to Acute myocardial infarction

Non-specific codes like I21 require more digits to indicate the appropriate level of specificity. Consider using any of the following ICD-10-CM codes with a higher level of specificity when coding for acute myocardial infarction:

  • I21.0 for ST elevation (STEMI) myocardial infarction of anterior wall - NON-BILLABLE CODE

  • Use I21.01 for ST elevation (STEMI) myocardial infarction involving left main coronary artery - BILLABLE CODE

  • Use I21.02 for ST elevation (STEMI) myocardial infarction involving left anterior descending coronary artery - BILLABLE CODE

  • Use I21.09 for ST elevation (STEMI) myocardial infarction involving other coronary artery of anterior wall - BILLABLE CODE

  • I21.1 for ST elevation (STEMI) myocardial infarction of inferior wall - NON-BILLABLE CODE

  • Use I21.11 for ST elevation (STEMI) myocardial infarction involving right coronary artery - BILLABLE CODE

  • Use I21.19 for ST elevation (STEMI) myocardial infarction involving other coronary artery of inferior wall - BILLABLE CODE

  • I21.2 for ST elevation (STEMI) myocardial infarction of other sites - NON-BILLABLE CODE

  • Use I21.21 for ST elevation (STEMI) myocardial infarction involving left circumflex coronary artery - BILLABLE CODE

  • Use I21.29 for ST elevation (STEMI) myocardial infarction involving other sites - BILLABLE CODE

  • Use I21.3 for ST elevation (STEMI) myocardial infarction of unspecified site - BILLABLE CODE

  • Use I21.4 for Non-ST elevation (NSTEMI) myocardial infarction - BILLABLE CODE

  • Use I21.9 for Acute myocardial infarction, unspecified - BILLABLE CODE

  • I21.A for Other type of myocardial infarction - NON-BILLABLE CODE

  • Use I21.A1 for Myocardial infarction type 2 - BILLABLE CODE

  • Use I21.A9 for Other myocardial infarction type - BILLABLE CODE

  • Use I21.B for Myocardial infarction with coronary microvascular dysfunction - BILLABLE CODE

Clinical Information

  • Acute Myocardial Infarction

    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.
  • Acute Myocardial Infarction by ECG Finding|ACUTE MYOCARDIAL INFARCTION|Acute Myocardial Infarction|Acute Myocardial Infarction by EKG Finding

    an electrocardiographic finding showing a current of injury with st elevation. no specification is provided for localization. (cdisc)
  • Acute Myocardial Infarction From PCI Complication Type|PCI Acute Angiographic Complication|PCI Acute Angiographic Complication|PCI Acute Angiographic Complication|PCIAAC|PCIAAC

    a description of the complications from a percutaneous coronary intervention procedure that lead to an acute myocardial ischemic event.
  • Acute Myocardial Infarction Type|ACMITYPE|ACMITYPE

    a classification or description of the acute myocardial infarction.
  • Death due to Acute Myocardial Infarction Related to COVID-19|Death due to acute MI

    death by any cardiovascular mechanism (e.g., arrhythmia, sudden death, heart failure (hf), stroke, pulmonary embolus, peripheral arterial disease) less than or equal to 30 days after a myocardial infarction (mi), related to the immediate consequences of the mi, such as progressive hf or recalcitrant arrhythmia in a patient with probable or confirmed acute covid-19.

Tabular List of Diseases and Injuries

The following annotation back-references are applicable to this diagnosis code. The Tabular List of Diseases and Injuries is a list of ICD-10-CM codes, organized "head to toe" into chapters and sections with coding notes and guidance for inclusions, exclusions, descriptions and more.


Includes

Includes
This note appears immediately under a three character code title to further define, or give examples of, the content of the category.
  • 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

Use Additional Code
The “use additional code” indicates that a secondary code could be used to further specify the patient’s condition. This note is not mandatory and is only used if enough information is available to assign an 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

Type 2 Excludes
A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.
  • old myocardial infarction I25.2
  • postmyocardial infarction syndrome I24.1
  • subsequent type 1 myocardial infarction I22

Patient Education


Heart Attack

Each year almost 800,000 Americans have a heart attack. A heart attack happens when blood flow to the heart suddenly becomes blocked. Without the blood coming in, the heart can't get oxygen. If not treated quickly, the heart muscle begins to die. But if you do get quick treatment, you may be able to prevent or limit damage to the heart muscle. That's why it's important to know the symptoms of a heart attack and call 911 if you or someone else is having them. You should call, even if you are not sure that it is a heart attack.

The most common symptoms in men and women are:

  • Chest discomfort. It is often in center or left side of the chest. It usually lasts more than a few minutes. It may go away and come back. It can feel like pressure, squeezing, fullness, or pain. It also can feel like heartburn or indigestion.
  • Shortness of breath. Sometimes this is your only symptom. You may get it before or during the chest discomfort. It can happen when you are resting or doing a little bit of physical activity.
  • Discomfort in the upper body. You may feel pain or discomfort in one or both arms, the back, shoulders, neck, jaw, or upper part of the stomach.

You may also have other symptoms, such as nausea, vomiting, dizziness, and lightheadedness. You may break out in a cold sweat. Sometimes women will have different symptoms then men. For example, they are more likely to feel tired for no reason.

The most common cause of heart attacks is coronary artery disease (CAD). With CAD, there is a buildup of cholesterol and other material, called plaque, on their inner walls or the arteries. This is atherosclerosis. It can build up for years. Eventually an area of plaque can rupture (break open). A blood clot can form around the plaque and block the artery.

A less common cause of heart attack is a severe spasm (tightening) of a coronary artery. The spasm cuts off blood flow through the artery.

At the hospital, health care providers make a diagnosis based on your symptoms, blood tests, and different heart health tests. Treatments may include medicines and medical procedures such as coronary angioplasty. After a heart attack, cardiac rehabilitation and lifestyle changes can help you recover.

NIH: National Heart, Lung, and Blood Institute


[Learn More in MedlinePlus]

Code History

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.