ICD-10-CM > I00-I99 > I20-I25 > I21 > I21.2 I21.2 ST elevation (STEMI) myocardial infarction of other sites Non-Billable/Non-Specific Applicable To Type 1 ST elevation myocardial infarction of other sites Codes I21.21ST elevation (STEMI) myocardial infarction involving left circumflex coronary arteryI21.29ST elevation (STEMI) myocardial infarction involving other sites