Skip to main content

I21.A9 vs T82.897

I21.A9 (Other myocardial infarction type) compared with T82.897 (Other specified complication of cardiac prosthetic devices, implants and grafts), from the official CMS tabular data.

Current data releases:ICD-10-CM FY2027 · ICD-10-PCS FY2027 · HCPCS October 2026 · MS-DRG v44 · Medicare Code Editor v44.0 · NCCI PTP Q4 2026 · MUE Q4 2026 · NCD code lists 2026-01 · LCD export September 28, 2026 · All releases and sources

Summary

These codes may both be needed to describe one condition, because I21.A9 carries a Code Also note covering T82.897.

Official rule
What is different?

The conditions named, billing status and chapter.I21.A9 is “Other myocardial infarction type”; T82.897 is “Other specified complication of cardiac prosthetic devices, implants and grafts”. T82.897 is a non-billable header; I21.A9 is billable. I21.A9 sits in I00-I99 — Diseases of the Circulatory System (I00-I99); T82.897 in S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88).

Registry fact

Can these codes be reported together?

Yes, and both may be needed.I21.A9 carries a Code Also note covering T82.897: “(acute) stent occlusion (T82.897-)”. The two may both be required to fully describe the condition; the note states no sequencing order.

Official ruleGuide: Code First vs Use Additional Code vs Code Also

Is one a parent or header code?

One is a header.T82.897 is a non-billable header, but I21.A9 is not one of its subdivisions.

Registry fact

Are there sequencing instructions?

No order is given.The Code Also note linking them states no sequencing order; sequence by the reason for the encounter.

Official ruleGuide: Code First vs Use Additional Code vs Code Also

Are there other coding relationships?

Yes.Both codes may be needed together. I21.A9 carries a Code Also note covering T82.897: “(acute) stent occlusion (T82.897-)”

Official ruleGuide: Code First vs Use Additional Code vs Code Also

Nothing found in 2 other checks; 1 check does not apply
Is there an Excludes1 relationship?

None.Neither entry carries an Excludes1 note that names the other code.

Official rule

Is there an Excludes2 relationship?

None.Neither entry carries an Excludes2 note that names the other code. I21.A9 carries 3 Excludes2 notes and T82.897 carries 22 Excludes2 notes covering other codes; the side-by-side table quotes them.

Official rule

Is one more specific?

Not comparable.The codes sit in different categories; specificity is only comparable within one category.

Official rule: a tabular instructional note or a section of the ICD-10-CM Official Guidelines, quoted as published. Registry fact: the codes’ own published attributes (titles, billable status, position in the hierarchy, code set). MedCoder-derived: a reading MedCoder computes from those facts; it is not itself a rule. How to read the labels

Can these codes be reported together?

Informational

Code Also relationship

I21.A9
Other myocardial infarction type
↔
T82.897
Other specified complication of cardiac prosthetic devices, implants and grafts

What we found

Both codes may be needed together.I21.A9 carries a Code Also note covering T82.897: “(acute) stent occlusion (T82.897-)”

A Code Also note means the two codes may both be required to fully describe the condition. CMS states no sequencing order for it — sequence by the reason for the encounter.

What to review

Report both when both are needed to describe the condition, sequenced by the reason for the encounter.

Guide: Code First vs Use Additional Code vs Code AlsoCheck these on a claim

Why it matters

A "Code Also" note means two codes may be required together, but the Guidelines state no sequencing order for it -- sequence by the reason for the encounter, not by this relationship.

Source / rule

CMS ICD-10-CM tabular instructional notes

Official guidance behind these answers

  • Section I.A.17 — “Code also ” note · applies to: Code also

    A “code also” note instructs that two codes may be required to fully describe a condition, but this note does not provide sequencing direction. The sequencing depends on the circumstances of the encounter.

    ICD-10-CM Official Guidelines FY2027

Quoted from the ICD-10-CM Official Guidelines for Coding and Reporting in effect for the release shown. The tabular notes above are the code-level instruction; these sections are the convention that says how such a note is applied. Source document (CMS PDF) · Release and checksum

Side by side

Similar descriptions do not make codes interchangeable. The documentation and the official instructions decide which code applies.

Official descriptionDiffers
I21.A9

Other myocardial infarction type

T82.897

Other specified complication of cardiac prosthetic devices, implants and grafts

StatusDiffers
I21.A9
Billable
T82.897
Non-billable header

A header is not reported on a claim; a code beneath it is.

Report instead: T82.897A, T82.897D, T82.897S

Excludes2Differs
I21.A9
  • old myocardial infarction (I25.2)
  • postmyocardial infarction syndrome (I24.1)
  • subsequent type 1 myocardial infarction (I22.-)
T82.897
  • failure and rejection of transplanted organs and tissue (T86.-)
  • any encounters with medical care for postprocedural conditions in which no complications are present, such as:
  • artificial opening status (Z93.-)
  • closure of external stoma (Z43.-)
  • fitting and adjustment of external prosthetic device (Z44.-)
  • burns and corrosions from local applications and irradiation (T20-T32)
  • complications of surgical procedures during pregnancy, childbirth and the puerperium (O00-O9A)
  • mechanical complication of respirator [ventilator] (J95.850)
  • poisoning and toxic effects of drugs and chemicals (T36-T65 with fifth or sixth character 1-4 or 6)
  • postprocedural fever (R50.82)
  • specified complications classified elsewhere, such as:
  • cerebrospinal fluid leak from spinal puncture (G97.0)
  • colostomy malfunction (K94.0-)
  • disorders of fluid and electrolyte imbalance (E86-E87)
  • functional disturbances following cardiac surgery (I97.0-I97.1)
  • intraoperative and postprocedural complications of specified body systems (D78.-, E36.-, E89.-, G97.3-, G97.4, H59.3-, H59.-, H95.2-, H95.3, I97.4-, I97.5, J95.6-, J95.7, K91.6-, L76.-, M96.-, N99.-)
  • ostomy complications (J95.0-, K94.-, N99.5-)
  • postgastric surgery syndromes (K91.1)
  • postlaminectomy syndrome NEC (M96.1)
  • postmastectomy lymphedema syndrome (I97.2)
  • postsurgical blind-loop syndrome (K91.2)
  • ventilator associated pneumonia (J95.851)
Code firstDiffers
I21.A9
  • , if applicable, postprocedural myocardial infarction following cardiac surgery (I97.190), or postprocedural myocardial infarction during cardiac surgery (I97.790)
T82.897

None at this code

Use additional codeDiffers
I21.A9
  • 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)
T82.897
  • code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5)
  • code(s) to identify the specified condition resulting from the complication
  • code to identify devices involved and details of circumstances (Y62-Y82)
Code alsoDiffers
I21.A9
  • complication, if known and applicable, such as:
  • (acute) stent occlusion (T82.897-)
  • (acute) stent stenosis (T82.855-)
  • (acute) stent thrombosis (T82.867-)
  • cardiac arrest due to underlying cardiac condition (I46.2)
  • complication of percutaneous coronary intervention (PCI) (I97.89)
  • occlusion of coronary artery bypass graft (T82.218-)
  • the presence of hypertension (I10-I1A)
T82.897

None at this code

CategoryDiffers
I21.A9

I21 Acute myocardial infarction

T82.897

T82 Complications of cardiac and vascular prosthetic devices, implants and grafts

ChapterDiffers
I21.A9

I00-I99 — Diseases of the Circulatory System (I00-I99)

T82.897

S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88)

IncludesDiffers
I21.A9
  • 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
  • Myocardial infarction associated with revascularization procedure
  • Myocardial infarction type 3
  • Myocardial infarction type 4a
  • Myocardial infarction type 4b
  • Myocardial infarction type 4c
  • Myocardial infarction type 5
T82.897

None at this code

7th characterDiffers
I21.A9

None at this code

T82.897
  • The appropriate 7th character is to be added to each code from category T82

No Excludes1 note at either code.

Notes are the code’s own tabular entry, quoted as published. A note that names the other code is the one the verdict above rests on. In a row that differs, each code’s own notes are listed under it, and the notes every code shares are listed once beneath them.

Edit this comparisonCheck a whole claim

Derived from the official CMS ICD-10-CM tabular data (FY2027). A coding-rule comparison, not billing advice: payer-specific edits and medical-necessity policy are outside its scope. All data sources