I21.4

Billable code

Non-ST elevation (NSTEMI) myocardial infarction

The ICD-10 code for non-st elevation (nstemi) myocardial infarction is I21.4.

Clinical notes

Also known as

Alternate wording, synonyms, or specific conditions that fall under this code, listed to help confirm you've picked the right one.

Acute subendocardial myocardial infarction
Non-Q wave myocardial infarction NOS
Nontransmural myocardial infarction NOS
Type 1 non-ST elevation myocardial infarction

Documentation support

General coding-documentation guidance — not a substitute for payer-specific requirements or professional coding judgment.

•As a general rule, code to the highest level of specificity supported by the documentation in the medical record.

Related codes in this category

ICD-9-CM equivalent

Informational only — GEM mappings are approximate, not guaranteed one-to-one equivalents. Verify before use in billing.

41071Approximate match
41070Approximate match
41072Approximate match

View full ICD-10 → ICD-9 crosswalk →

Associated MS-DRGs

I21.4 can serve as the principal diagnosis for these Medicare Severity Diagnosis-Related Groups.

Informational only — actual DRG assignment also depends on procedures, complications/comorbidities (CC/MCC), discharge status, and payer-specific rules not reflected here.