ICD-10-CM > I00-I99 > I20-I25 > I22 > I22.9 I22.9 Subsequent ST elevation (STEMI) myocardial infarction of unspecified site Billable/Specific Copy Code Copy Description Applicable To Subsequent acute myocardial infarction of unspecified siteSubsequent myocardial infarction (acute) NOS