Non-ST elevation (NSTEMI) myocardial infarction
- I21.4 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
- The 2025 edition of ICD-10-CM I21.4 became effective on October 1, 2024.
- This is the American ICD-10-CM version of I21.4 – other international versions of ICD-10 I21.4 may differ.
Applicable To
- Acute subendocardial myocardial infarction
- Non-Q wave myocardial infarction NOS
- Nontransmural myocardial infarction NOS
- Type 1 non-ST elevation myocardial infarction
The following code(s) above I21.4 contain annotation back-references
that may be applicable to I21.4:
- I00-I99 Diseases of the circulatory system
- I20-I25 Ischemic heart diseases
- I21 Acute myocardial infarction
Approximate Synonyms
- Acute non-st segment elevation myocardial infarction
- Heart attack
Clinical Information
- A myocardial infarction in the absence of observable q wave abnormalities in the ecg.
ICD-10-CM I21.4 is grouped within Diagnostic Related Group(s) (MS-DRG v42.0):
- 280 Acute myocardial infarction, discharged alive with mcc
- 281 Acute myocardial infarction, discharged alive with cc
- 282 Acute myocardial infarction, discharged alive without cc/mcc
- 283 Acute myocardial infarction, expired with mcc
- 284 Acute myocardial infarction, expired with cc
- 285 Acute myocardial infarction, expired without cc/mcc
Convert I21.4 to ICD-9-CMCode History
- 2016 (effective 10/1/2015): New code (first year of non-draft ICD-10-CM)
- 2017 (effective 10/1/2016): No change
- 2018 (effective 10/1/2017): No change
- 2019 (effective 10/1/2018): No change
- 2020 (effective 10/1/2019): No change
- 2021 (effective 10/1/2020): No change
- 2022 (effective 10/1/2021): No change
- 2023 (effective 10/1/2022): No change
- 2024 (effective 10/1/2023): No change
- 2025 (effective 10/1/2024): No change
Diagnosis Index entries containing back-references to I21.4:
- Infarct, infarction
- myocardium, myocardial (acute) (with stated duration of 4 weeks or less) I21.9
- non-ST elevation (NSTEMI) I21.4
- non-Q wave I21.4
- nontransmural I21.4
- nontransmural I21.4
- subendocardial I21.4 (acute) (nontransmural)
- myocardium, myocardial (acute) (with stated duration of 4 weeks or less) I21.9
- Necrosis, necrotic (ischemic) – see also Gangrene
- subendocardial (acute) I21.4