ICD-10 Code I22.8 – Subsequent ST elevation (STEMI) myocardial infarction of other sites (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I22.8 – Subsequent ST elevation (STEMI) myocardial infarction of other sites
What it is
I22.8 identifies a new ST-elevation myocardial infarction occurring after a recent acute MI, when the infarct site is other than the standard coded locations. Use it for a subsequent STEMI, not the initial event.
Clinical signs
Clinical features vary; refer to documentation. Typical STEMI findings include acute ischemic chest pain, ECG evidence of ST elevation, and biomarker evidence of myocardial injury, with the infarct location described as other sites.
When to use this code
Use this code when the record clearly states a subsequent STEMI after a recent MI and the provider documents the infarct site as other sites. It is appropriate only for the later event, not the original infarction. Check documentation for timing and site specificity.
Do not use for
Do not use I22.8 for the initial acute MI, for NSTEMI, or when the site is unspecified or coded elsewhere. If the documentation does not confirm a subsequent event, check documentation.
Coding tip
Confirm that the chart supports a recent prior MI before assigning I22.8.