ICD-10 Code I21.02 – ST elevation (STEMI) myocardial infarction involving left anterior descending coronary artery (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I21.02 – ST elevation (STEMI) myocardial infarction involving left anterior descending coronary artery
What it is
This code identifies an acute ST-elevation myocardial infarction caused by blockage in the left anterior descending coronary artery. Use it when documentation specifies the LAD as the infarct-related artery.
Clinical signs
Typical findings include acute chest pain, ischemic ECG changes with ST elevation, and evidence of myocardial injury. Clinical features vary; refer to documentation for the culprit vessel and confirmed STEMI diagnosis.
When to use this code
Use I21.02 when the provider documents STEMI involving the left anterior descending coronary artery, including anterior or anteroseptal infarction tied to that vessel. Code only when the record clearly links the acute infarction to the LAD. Check documentation if the artery is not specified.
Do not use for
Do not use this code for NSTEMI, old myocardial infarction, or chest pain without confirmed infarction. If the coronary artery is not documented as the LAD, choose the code supported by the record.
Coding tip
Verify that the acute STEMI and the LAD culprit vessel are both documented before assigning I21.02.