I21.4
BillableNon-ST elevation (NSTEMI) myocardial infarction
Non-ST elevation (NSTEMI) myocardial infarction
Coding Notes
Inclusion Terms
Alternative clinical terms for this condition
- Acute subendocardial myocardial infarction
- Non-Q wave myocardial infarction NOS
- Nontransmural myocardial infarction NOS
- Type 1 non-ST elevation myocardial infarction
Includes
Conditions included under this code
- 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
Excludes 2
Conditions not included here, but the patient may have both
- •certain conditions originating in the perinatal periodP04-P96
- •certain infectious and parasitic diseasesA00-B99
- •complications of pregnancy, childbirth and the puerperiumO9A)O00
- •congenital malformations, deformations, and chromosomal abnormalitiesQ00-Q99
- •endocrine, nutritional and metabolic diseasesE00-E88
- •injury, poisoning and certain other consequences of external causesS00-T88
- •neoplasmsC00-D49
- •symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classifiedR00-R94
- •systemic connective tissue disordersM30-M36
- •transient cerebral ischemic attacks and related syndromesG45
- •old myocardial infarctionI25.2
- •postmyocardial infarction syndromeI24.1
- •subsequent type 1 myocardial infarctionI22
Use Additional Code
Additional codes that should follow this code
- code, if applicable, to identify:
- •exposure to environmental tobacco smokeZ77.22
- •history of tobacco dependenceZ87.891
- •occupational exposure to environmental tobacco smokeZ57.31
- •status post administration of tPA (rtPA) in a different facility within the last 24 hours prior to admission to current facilityZ92.82
- •tobacco dependenceF17
- •tobacco useZ72.0
Code Also
A second code may be required; sequencing depends on circumstances
Related Codes(7)
I21.0ST elevation (STEMI) myocardial infarction of anterior wall
I21.1ST elevation (STEMI) myocardial infarction of inferior wall
I21.2ST elevation (STEMI) myocardial infarction of other sites
I21.3ST elevation (STEMI) myocardial infarction of unsp site
I21.9Acute myocardial infarction, unspecified
I21.AOther type of myocardial infarction
I21.BMyocardial infarction with coronary microvascular dysfnct
ICD-11 Equivalents(1)
ICD-11 Equivalents
View full mappingCorresponding ICD-11 codes from the WHO crosswalk mapping
Also Known As / Clinical Terms(103)
SNOMED CT
- Acute anteroseptal myocardial infarction62695002
- Acute inferolateral myocardial infarction65547006
- Acute myocardial infarction of inferolateral wall65547006
- Acute anterolateral myocardial infarction70211005
- Acute myocardial infarction of anterolateral wall70211005
- Acute subendocardial infarction70422006
- Acute inferior myocardial infarction73795002
- Acute myocardial infarction of diaphragmatic wall73795002
- Acute myocardial infarction of inferior wall73795002
- Postoperative myocardial infarction129574000
- ECG: myocardial infarction164865005
- EKG: myocardial infarction164865005
- Electrocardiogram finding of infarction164865005
- Electrocardiographic myocardial infarction164865005
- ECG: subendocardial infarct164870003
- EKG: subendocardial infarct164870003
- Electrocardiographic subendocardial infarct164870003
- Acute non-Q wave infarction - anteroseptal233826005
- Acute non-Q wave infarction - anterolateral233828006
- Acute non-Q wave infarction - inferior233830008
- Acute non-Q wave infarction - inferolateral233832000
- Acute non-Q wave infarction - lateral233834004
- Acute widespread myocardial infarction233835003
- Acute non-Q wave infarction - widespread233837006
- Acute non-Q wave infarction307140009
- Postoperative subendocardial myocardial infarction311796008
- Non-Q wave myocardial infarction314207007
- Acute non-ST segment elevation myocardial infarction401314000
- NSTEMI - Non-ST segment elevation MI401314000
- Acute myocardial infarction of anterior wall involving right ventricle703252002
- Acute myocardial infarction of anterior wall with right ventricular involvement703252002
- Acute myocardial infarction of right ventricle836293000
- Acute right ventricular myocardial infarction836293000
- Isolated right ventricular myocardial infarction836293000
- Acute inferior non-ST segment elevation myocardial infarction of right ventricle1204151009
- Acute inferior non-ST segment elevation myocardial infarction1204152002
- Acute anterior non-ST segment elevation myocardial infarction with right ventricular involvement1204154001
- Acute anterior non-ST segment elevation myocardial infarction1204155000
- Acute non-ST segment elevation myocardial infarction of right ventricle1204222000
- Subendocardial myocardial infarction380001000004106
UMLS
- Acute subendocardial myocardial infarctionC0494580
- Non-Q wave myocardial infarctionC0542269
- Non-Q wave myocardial infarction (disorder)C0542269
- Non-Q wave myocardial infarction NOSC0542269
- infarction myocardial non q waveC0542269
- non q wave myocardial infarctionC0542269
- non q-wave myocardial infarctionC0542269
- non-q wave myocardial infarctionC0542269
- nqmiC0542269
- nqwmiC0542269
- Non-ST elevation (NSTEMI) myocardial infarctionC1561921
- Nontransmural myocardial infarction NOSC1400511
- Type 1 non-ST elevation myocardial infarctionC4509200
Clinical Terms
- Acute non-Q wave infarction - widespread
- Acute myocardial infarction of anterior wall involving right ventricle
- Electrocardiographic subendocardial infarct
- ECG: myocardial infarction
- Electrocardiogram finding of infarction
- Acute non-ST segment elevation myocardial infarction
- Acute non-Q wave infarction - anterolateral
- Acute subendocardial myocardial infarction
- Acute myocardial infarction of anterolateral wall
- EKG: myocardial infarction
- nqmi
- Postoperative subendocardial myocardial infarction
- Non-Q wave myocardial infarction (disorder)
- Type 1 non-ST elevation myocardial infarction
- Electrocardiographic myocardial infarction
- Isolated right ventricular myocardial infarction
- Acute anterior non-ST segment elevation myocardial infarction with right ventricular involvement
- Acute widespread myocardial infarction
- Acute myocardial infarction of diaphragmatic wall
- Acute non-Q wave infarction - inferolateral
- Acute non-Q wave infarction - inferior
- NSTEMI - Non-ST segment elevation MI
- Subendocardial myocardial infarction
- infarction myocardial non q wave
- Acute non-Q wave infarction - anteroseptal
- Acute myocardial infarction of anterior wall with right ventricular involvement
- Non-Q wave myocardial infarction NOS
- Acute non-Q wave infarction - lateral
- nqwmi
- non q-wave myocardial infarction
- EKG: subendocardial infarct
- Acute inferior myocardial infarction
- Acute anteroseptal myocardial infarction
- Acute myocardial infarction of right ventricle
- Acute non-ST segment elevation myocardial infarction of right ventricle
- Acute anterolateral myocardial infarction
- Nontransmural myocardial infarction NOS
- Acute myocardial infarction of inferolateral wall
- Acute anterior non-ST segment elevation myocardial infarction
- Acute right ventricular myocardial infarction
- Acute inferior non-ST segment elevation myocardial infarction
- non-q wave myocardial infarction
- Acute inferior non-ST segment elevation myocardial infarction of right ventricle
- Acute myocardial infarction of inferior wall
- Acute non-Q wave infarction
- Acute inferolateral myocardial infarction
- ECG: subendocardial infarct
- Acute subendocardial infarction
- non q wave myocardial infarction
- Postoperative myocardial infarction
Frequently Asked Questions
What is the ICD-10 code for non-st elevation (nstemi) myocardial infarction?
The ICD-10-CM code for non-st elevation (nstemi) myocardial infarction is I21.4. The full clinical description is "Non-ST elevation (NSTEMI) myocardial infarction". I21.4 is a billable/specific code that can be used on insurance claims and medical billing.
What does ICD-10 code I21.4 mean?
ICD-10-CM code I21.4 represents “Non-ST elevation (NSTEMI) myocardial infarction”. It is classified under Chapter 9: Diseases of the Circulatory System and is a billable/specific code that can be used on a claim.
Is I21.4 a billable code?
Yes, I21.4 is a billable/specific ICD-10-CM code and can be used to indicate a diagnosis on a medical claim.
What chapter is I21.4 in?
I21.4 is in Chapter 9: Diseases of the Circulatory System (codes I00-I99).
Are additional codes required with I21.4?
Yes, when using I21.4, also report: 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).
What SNOMED CT codes does I21.4 map to?
I21.4 maps to 27 SNOMED CT concepts: 1204155000, 1204154001, 70211005, 62695002, 73795002, and 22 more. SNOMED CT is a clinical terminology used in electronic health records.
What are the UMLS CUIs for I21.4?
I21.4 is linked to 5 UMLS Concept Unique Identifiers: C0494580, C0542269, C1561921, C1400511, C4509200. The UMLS (Unified Medical Language System) integrates multiple biomedical vocabularies maintained by the U.S. National Library of Medicine.
How does I21.4 relate to ICF functioning codes?
ICF (International Classification of Functioning, Disability and Health) codes describe how conditions like non-st elevation (nstemi) myocardial infarction affect a person's functioning — body functions, activities, participation, and environmental factors. AutoICD provides ICF Core Sets for 12+ conditions and can map clinical text to ICF categories automatically. Browse the ICF directory to explore functioning codes.
What is the ICD-11 equivalent of I21.4?
I21.4 maps to the ICD-11 code: BA41.Z (Acute myocardial infarction, unspecified).
Automate ICD-10 Coding With AI
Send clinical text to the AutoICD API and get back structured ICD-10 codes with confidence scores. Integrates into any EHR or billing system in minutes.
Includes SNOMED Clinical Terms® (SNOMED CT®) used by permission of SNOMED International. Includes content from the UMLS Metathesaurus, courtesy of the U.S. National Library of Medicine.