MCMCB Pro
I22.1

I22.1Subsequent ST elevation (STEMI) myocardial infarction of inferior wall

Billable / specific codeICD-10-CM

I22.1 is a billable, specific ICD-10-CM code for subsequent st elevation (stemi) myocardial infarction of inferior wall. It is valid for submission on a claim.

Inclusion terms

Alternative wordings a physician may use in the chart for this same code.

  • Subsequent acute transmural myocardial infarction of inferior wall
  • Subsequent transmural (Q wave) infarction (acute)(of) diaphragmatic wall
  • Subsequent transmural (Q wave) infarction (acute)(of) inferior (wall) NOS
  • Subsequent inferolateral transmural (Q wave) infarction (acute)
  • Subsequent inferoposterior transmural (Q wave) infarction (acute)

Risk adjustment

I22.1 risk-adjusts. Under the CMS-HCC V28 model it maps to this category:

  • HCC 228 Acute Myocardial Infarction0.252 RAF

Coefficient shown for the Community Non-dual Aged segment. A higher HCC in the same hierarchy will suppress this one, so capturing it does not always add score.

Medicare coverage

I22.1 is named in 61 Medicare coverage policies 61 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

  • A52458Automatic External Defibrillators - Policy Article
  • A52458Automatic External Defibrillators - Policy Article
  • A52850Billing and Coding: Cardiac Catheterization and Coronary Angiography
  • A52850Billing and Coding: Cardiac Catheterization and Coronary Angiography

How I22.1 is indexed

Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to I22.1.

  • Infarct, infarctionmyocardium, myocardialsubsequentdiaphragmatic(wall)
  • Infarct, infarctionmyocardium, myocardialsubsequentinferior(diaphragmatic) (inferolateral) (inferoposterior) (wall)
  • Infarct, infarctionmyocardium, myocardialST elevationinferior NECsubsequent
  • Infarct, infarctionmyocardium, myocardialsubsequentST elevationinferior(diaphragmatic) (inferolateral) (inferoposterior) (wall)
  • Infarct, infarctionmyocardium, myocardialsubsequenttransmuraldiaphragmatic(wall)
  • Infarct, infarctionmyocardium, myocardialsubsequenttransmuralinferior(diaphragmatic) (inferolateral) (inferoposterior) (wall)

Related codes at this level

Codes that share I22. If I22.1 is not quite right, the correct code is usually one of these.

Questions about I22.1

Is I22.1 a billable ICD-10-CM code?
Yes. I22.1 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does I22.1 sit in the tabular list?
Diseases of the circulatory system (I00-I99), in the block Ischemic heart diseases (I20-I25).
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.