I21.9

Acute myocardial infarction, unspecified

Billable / specificHCC V28 228

I21.9 is a billable, specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes in FY2027.

Inclusion terms

cardiac infarction
coronary (artery) embolism
coronary (artery) occlusion
coronary (artery) rupture
coronary (artery) thrombosis
infarction of heart, myocardium, or ventricle
myocardial infarction specified as acute or with a stated duration of 4 weeks (28 days) or less from onset

Not included here — may be reported together when both conditions exist.

certain conditions originating in the perinatal period (P04-P96) (from I21)
certain infectious and parasitic diseases (A00-B99) (from I21)
complications of pregnancy, childbirth and the puerperium (O00-O9A) (from I21)
congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99) (from I21)
endocrine, nutritional and metabolic diseases (E00-E88) (from I21)
injury, poisoning and certain other consequences of external causes (S00-T88) (from I21)
neoplasms (C00-D49) (from I21)
symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94) (from I21)
systemic connective tissue disorders (M30-M36) (from I21)
transient cerebral ischemic attacks and related syndromes (G45.-) (from I21)
old myocardial infarction (I25.2) (from I21)
postmyocardial infarction syndrome (I24.1) (from I21)
subsequent type 1 myocardial infarction (I22.-) (from I21)

Add a code to identify the following, if applicable.

code, if applicable, to identify: (from I21)
exposure to environmental tobacco smoke (Z77.22) (from I21)
history of tobacco dependence (Z87.891) (from I21)
occupational exposure to environmental tobacco smoke (Z57.31) (from I21)
status post administration of tPA (rtPA) in a different facility within the last 24 hours prior to admission to current facility (Z92.82) (from I21)
tobacco dependence (F17.-) (from I21)
tobacco use (Z72.0) (from I21)

An additional code may be needed.