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Heart attack ICD-10-CM Codes

Heart attack ICD-10-CM search: Acute myocardial infarction (I21) and the related coding concepts MedCoder holds for it. Concepts covered: Acute myocardial infarction, Subsequent myocardial infarction, Complications following myocardial infarction, Old myocardial infarction. Results are organised from ICD-10-CM, Coding Guidance, HCPCS Level II.

What MedCoder understood

You searched
heart attack
MedCoder understood
myocardial infarction
Search type
ICD-10-CM diagnosis / coding concept
Primary registry
ICD-10-CM
Primary concept
Acute myocardial infarction

“Heart attack” is coded in ICD-10-CM as myocardial infarction, and the tabular separates an initial acute infarction, a subsequent infarction within four weeks, current complications following an infarction, and an old (healed) infarction. The concepts below are those distinctions.

Direct match in the official descriptions

4 coding concepts · 9 codes

Registry results: 35 results · 3 registriesICD-10-CM: 32+ matchesCoding Guidance: 1 matchHCPCS Level II: 2 matches

The ICD-10-CM count is capped at 32: the search stops counting there, so the registry may hold more.

  • Understood as a diagnosis or condition search, so ICD-10-CM is ranked first.
  • heart attack → myocardial infarction

What are you looking for?

Selecting a pathway filters the results below. It does not select a code.

Acute (initial) infarctionSubsequent infarctionComplications following infarctionOld / healed infarctionI’m not sure

Search results are not a code assignment. Review the documentation, official coding instructions, and applicable rules before selecting a code.

Primary ICD-10-CM result

I21Acute myocardial infarction

The ICD-10-CM family for an initial acute myocardial infarction.

17 codes · 13 billable · ICD-10-CM FY2026

Explore I21 →

Specific pathways under I21

I21’s own subdivisions, grouped by the wording of their official descriptions.

ST elevation (STEMI)

Other myocardial infarction type

Unspecified

Other subdivisions

Best coding matches

The ICD-10-CM coding concepts this search covers, and the codes the published release carries for each.

Acute myocardial infarction

The initial infarction; type and site decide the subcode.

Subsequent myocardial infarction

A further infarction within four weeks of the initial one.

Complications following myocardial infarction

Current complications within the 28-day period.

Continue with MedCoder

For I21 Acute myocardial infarction

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Claim Check reads the official ICD-10-CM instructions for the codes entered. It is not a payer edit, a claims scrubber or a certified coding validator.

Strongest matches across registries

How Do I Code a Myocardial Infarction? I21 for Four Weeks, I22 for a Second MI Within Them, and I25.2 After
Coding Guide

An acute myocardial infarction is coded from category I21 for four weeks from onset: I21.9 when type and site are unspecified, I21.0–I21.3 for a type 1 STEMI by site, I21.4 for a type 1 NSTEMI, I21.A1 for a type 2 MI…

Guidance · Every search term appears in this guidance

Why this matched
  • Every search term appears in this guidance
I21.BMyocardial infarction with coronary microvascular dysfunction
ICD-10-CMBillable

Under I21 Acute myocardial infarction

Matched concept: myocardial infarction · heart attack → myocardial infarction

Why this matched
  • The searched wording is a recorded synonym of “myocardial infarction”, which appears in the official description.
  • heart attack → myocardial infarction
  • Sits under I21 Acute myocardial infarction in the ICD-10-CM tabular.
  • The tabular carries it at billable code level.

Explore I21

I21 Acute myocardial infarction — what its code page carries, from the official tables.

Hierarchy17· 13 billableIncludes7Excludes23Use Additional Code6Referenced by other codes6Coding guides1Code history3CompareClaim Check

Related concepts, from I21's tabular notes

Excludes2

Use Additional Code

ICD-10-CM: 32+ matches

See all in ICD-10-CM →

4 of them are shown above under Best coding matches.

I23Certain current complications following ST elevation (STEMI) and non-ST elevation (NSTEMI) myocardial infarction (within the 28 day period)
ICD-10-CMCategoryNot billable

9 codes below, all billable

View all 9 billable child codes →
I21.9Acute myocardial infarction, unspecified
ICD-10-CMBillable

Under I21 Acute myocardial infarction

I21.4Non-ST elevation (NSTEMI) myocardial infarction
ICD-10-CMBillable

Under I21 Acute myocardial infarction

I22.2Subsequent non-ST elevation (NSTEMI) myocardial infarction
ICD-10-CMBillable

Under I22 Subsequent ST elevation (STEMI) and non-ST elevation (NSTEMI) myocardial infarction

Coding Guidance

Its one match is shown above under Best matches.

HCPCS Level II: 2 matches

Show HCPCS Level II results 2 related results
C9606Percutaneous transluminal revascularization of acute total/subtotal occlusion during acute myocardial infarction, coronary artery or coronary artery bypass graft, any combination of drug-eluting intracoronary stent, atherectomy and angioplasty, including aspiration thrombectomy when performed, single vessel
HCPCS Level II
G9753Documentation of medical reason for not conducting a search for dicom format images for prior patient ct imaging studies completed at non-affiliated external healthcare facilities or entities within the past 12 months that are available through a secure, authorized, media-free, shared archive (e.g., trauma, acute myocardial infarction, stroke, aortic aneurysm where time is of the essence)
HCPCS Level II