ICD10
ICD-10 Code I22: Subsequent ST elevation (STEMI) and non-ST elevation (NSTEMI) myocardial infarction
Reviewed by HealthAssure Clinical TeamUpdated 21 May 2026
What is this code?
ICD-10 entries help standardize how diagnoses are organized for coding, reporting, analytics, and documentation. This code sits within the broader ICD-10 area for Diseases of the circulatory system (I00-I99).
đź“‹Clinical overview
This ICD-10 code is commonly used when documentation describes a subsequent myocardial infarction after a recent prior infarction. The most accurate code depends on whether the later infarction is STEMI versus NSTEMI and whether the site is anterior, inferior, other, or unspecified.
When is it used?
- May be used when a clinician documents subsequent st elevation (stemi) and non-st elevation (nstemi) myocardial infarction in a patient's medical record.
- May appear in hospital records, claims, referrals, and clinical documentation.
- This code may act more like a grouping or parent code, so a more specific child code may be used in final documentation when available.
What it does not mean
- A code alone does not explain severity, treatment plan, or outcome.
- A medical code should not be treated as a substitute for a doctor's diagnosis or advice.
- This entry may represent a broader category rather than the most specific billable code.
đź©şClinical context
When commonly used
- Inpatient, cardiology, emergency, and utilization-review workflows where the chart documents a subsequent myocardial infarction rather than the first acute event.
- Coding workflows where the record identifies subsequent STEMI versus subsequent NSTEMI and clarifies infarct territory, changing final code specificity.
Common management context
- Evaluation often includes recurrent-ischemia symptom review, ECG interpretation, troponin testing, coronary-imaging or catheterization context, and acute cardiology management planning.
- Documentation usually becomes more specific when the chart identifies subsequent STEMI versus NSTEMI and names anterior-wall, inferior-wall, other-site, or unspecified-site involvement.
- Specialist context already linked on this page includes Cardiologist, General Physician.
🔍Key distinctions
Important notes
- This ICD-10 family captures a subsequent myocardial infarction rather than the initial acute myocardial infarction itself.
- Subsequent STEMI versus NSTEMI pattern and infarct territory are what drive final code specificity inside this family.
- This parent page groups subsequent myocardial infarction patterns, so the final billable code usually depends on whether the later infarction is STEMI versus NSTEMI and whether the site is anterior, inferior, other, or unspecified.
- Subsequent STEMI is coded separately from subsequent NSTEMI within this follow-on myocardial-infarction family.
- Documentation that describes a subsequent myocardial infarction is coded differently from the initial acute myocardial infarction, chronic ischemic heart disease, or a remote healed prior infarction.
Important exclusions
- subsequent myocardial infarction, type 2 (I21.A1)
- subsequent myocardial infarction of other type (type 3) (type 4) (type 5) (I21.A9)
Related codes to consider
I22.0Subsequent ST elevation (STEMI) myocardial infarction of anterior wall
Related subsequent-myocardial-infarction ICD-10 code; documentation often becomes more specific when the chart identifies subsequent STEMI versus NSTEMI, infarct territory, or distinguishes the follow-on infarction from the initial acute event.
I22.1Subsequent ST elevation (STEMI) myocardial infarction of inferior wall
Related subsequent-myocardial-infarction ICD-10 code; documentation often becomes more specific when the chart identifies subsequent STEMI versus NSTEMI, infarct territory, or distinguishes the follow-on infarction from the initial acute event.
I22.2Subsequent non-ST elevation (NSTEMI) myocardial infarction
Related subsequent-myocardial-infarction ICD-10 code; documentation often becomes more specific when the chart identifies subsequent STEMI versus NSTEMI, infarct territory, or distinguishes the follow-on infarction from the initial acute event.
I22.8Subsequent ST elevation (STEMI) myocardial infarction of other sites
Related subsequent-myocardial-infarction ICD-10 code; documentation often becomes more specific when the chart identifies subsequent STEMI versus NSTEMI, infarct territory, or distinguishes the follow-on infarction from the initial acute event.
Code hierarchy
chapter
9Diseases of the circulatory system (I00-I99)
block
I20-I25Ischemic heart diseases
currentI20-I25
Official coding notes
Includes
- acute myocardial infarction occurring within four weeks (28 days) of a previous acute myocardial infarction, regardless of site
- cardiac infarction
- coronary (artery) embolism
- coronary (artery) occlusion
- coronary (artery) rupture
- coronary (artery) thrombosis
- infarction of heart, myocardium, or ventricle
- recurrent myocardial infarction
- reinfarction of myocardium
- rupture of heart, myocardium, or ventricle
- subsequent type 1 myocardial infarction
Applicable to
- code, if applicable, to identify:
- exposure to environmental tobacco smoke (Z77.22)
- history of tobacco dependence (Z87.891)
- occupational exposure to environmental tobacco smoke (Z57.31)
- status post administration of tPA (rtPA) in a different facility within the last 24 hours prior to admission to current facility (Z92.82)
- tobacco dependence (F17.-)
- tobacco use (Z72.0)
Excludes1 (do not code together)
- subsequent myocardial infarction, type 2 (I21.A1)
- subsequent myocardial infarction of other type (type 3) (type 4) (type 5) (I21.A9)
Use additional code
- code, if applicable, to identify:
- exposure to environmental tobacco smoke (Z77.22)
- history of tobacco dependence (Z87.891)
- occupational exposure to environmental tobacco smoke (Z57.31)
- status post administration of tPA (rtPA) in a different facility within the last 24 hours prior to admission to current facility (Z92.82)
- tobacco dependence (F17.-)
- tobacco use (Z72.0)
Where you may see this code
You may see this entry in coding references, medical records, or claims workflows when a broader diagnosis category is being reviewed before a more specific code is chosen.
Related specialists
CardiologistGeneral Physician
Related codes
I22.0Subsequent ST elevation (STEMI) myocardial infarction of anterior wallcodeI22.1Subsequent ST elevation (STEMI) myocardial infarction of inferior wallcodeI22.2Subsequent non-ST elevation (NSTEMI) myocardial infarctioncodeI22.8Subsequent ST elevation (STEMI) myocardial infarction of other sitescodeI22.9Subsequent ST elevation (STEMI) myocardial infarction of unspecified sitecode
Sibling codes
Coding guidelines
Compatibility
Legacy code aligns to an official FY 2026 category. Frontend should resolve to the official category page and surface the billable child codes.
Legacy codes
I22
Replacement codes
I22.0 — Subsequent ST elevation (STEMI) myocardial infarction of anterior wallI22.1 — Subsequent ST elevation (STEMI) myocardial infarction of inferior wallI22.2 — Subsequent non-ST elevation (NSTEMI) myocardial infarctionI22.8 — Subsequent ST elevation (STEMI) myocardial infarction of other sitesI22.9 — Subsequent ST elevation (STEMI) myocardial infarction of unspecified site
Common synonyms
Subsequent ST elevation (STEMI) and non-ST elevation (NSTEMI) myocardial infarctionSubsequent ST elevationSubsequent ST elevation STEMI and non-ST elevation NSTEMI myocardial infarction
Frequently asked questions
About this content
This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.