I22.9

Subsequent ST elevation (STEMI) myocardial infarction of unspecified site

Risk-adjusting (HCC)Billable code

HCC risk adjustment mapping

CMS-HCC V28

HCC228

Acute Myocardial Infarction

CMS-HCC ESRD V24

HCC86

Acute Myocardial Infarction

RxHCC V08

RXHCC188

Coronary Artery Disease

Coding notes

Excludes 1 never coded together · Excludes 2 may co-exist

This code · I22.9
Synonyms

Subsequent acute myocardial infarction of unspecified site Subsequent myocardial infarction (acute) NOS

Inherited from I22Subsequent STEMI & NSTEMI mocard infrc
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

Excludes 1

subsequent myocardial infarction, type 2 (I21.A1) subsequent myocardial infarction of other type (type 3) (type 4) (type 5) (I21.A9)

Use additional

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)

Inherited from I20-I25Ischemic heart diseases
Code also

the presence of hypertension (I10-I1A)

Inherited from chapter 9Diseases of the circulatory system
Excludes 2

certain conditions originating in the perinatal period (P04-P96) certain infectious and parasitic diseases (A00-B99) complications of pregnancy, childbirth and the puerperium (O00-O9A) congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99) endocrine, nutritional and metabolic diseases (E00-E88) injury, poisoning and certain other consequences of external causes (S00-T88) neoplasms (C00-D49) symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94) systemic connective tissue disorders (M30-M36) transient cerebral ischemic attacks and related syndromes (G45.-)

Official Guidelines for I22.9

FY 2026 ›

Sections that reference I22.9

Sections whose FY 2026 text names I22.9, its I22 category, or a range containing it — the chapter guidance above is the authoritative source.