I21.4
✓ BillableNon-ST elevation (NSTEMI) myocardial infarction
Diseases of the circulatory system (I00-I99)
Also Known As
Acute subendocardial myocardial infarctionNon-Q wave myocardial infarction NOSNontransmural myocardial infarction NOSType 1 non-ST elevation myocardial infarction
⚠️ Excludes2
inherited from I21Rules from parent category I21: Acute myocardial infarction
- • old myocardial infarction (I25.2)
- • postmyocardial infarction syndrome (I24.1)
- • subsequent type 1 myocardial infarction (I22.-)
📋 Code Instructions
from I21- • 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)
🧪 Validate Combinations
Add I21.4 to the Excludes Checker to validate against your full code list.
Open in Checker →Code Information
CodeI21.4
BillableYes
ParentI21
CategoryDiseases of the circulatory system (I00-I99)
Excludes10 rule(s)
Excludes23 note(s)
Data Source
CMS ICD-10-CM 2026 Tabular List
Updated October 1, 2025 (FY2026)