ICD-10 Code I21.11 – ST elevation (STEMI) myocardial infarction involving right coronary artery (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I21.11 – ST elevation (STEMI) myocardial infarction involving right coronary artery
What it is
I21.11 identifies an acute ST-elevation myocardial infarction affecting the right coronary artery. Use it when the record clearly documents STEMI with right coronary artery involvement.
Clinical signs
Typical findings include acute ischemic chest pain, ECG evidence of ST elevation, and documentation of infarction in the right coronary artery territory. Clinical features vary; refer to documentation.
When to use this code
Use this code when the provider states STEMI and specifies the right coronary artery as the infarct-related vessel. It is appropriate for confirmed acute myocardial infarction cases with that anatomic location. If the artery is not documented, check documentation before assigning this code.
Do not use for
Do not use it for NSTEMI, old myocardial infarction, or chest pain without confirmed infarction. Do not assign it when the infarct artery is documented differently or not specified.
Coding tip
Always verify that both STEMI and right coronary artery involvement are explicitly documented before coding I21.11.