Skip to main content

I23.4 ICD-10-CM Code: Rupture of chordae tendineae as current complication following acute myocardial infarction

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Coding at a Glance

Tabular directives
1 Excludes1 · 1 code-also instruction
Risk adjustment
CMS-HCC V28: 1 category · CMS-HCC V22 category 86 · RxHCC V08 category 188

Inpatient Payment Groups (MS-DRG)

Potential MS-DRG participation — not a DRG assignment.

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v43, Appendix B.

  • MS-DRG 306 — CARDIAC CONGENITAL AND VALVULAR DISORDERS WITH MCC (MDC 05)
  • MS-DRG 307 — CARDIAC CONGENITAL AND VALVULAR DISORDERS WITHOUT MCC (MDC 05)

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

Risk Adjustment (CMS-HCC)

Payment categories this diagnosis maps to under CMS-HCC V28, payment year 2026.

  • HCC 229 — Unstable Angina and Other Acute Ischemic Heart Disease

Other models: CMS-HCC V22 HCC 86 · RxHCC V08 HCC 188

Risk scores depend on the enrollee's full accepted diagnosis set and segment; a category mapping alone does not determine payment.

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for I23.4 in the official ICD-10-CM tabular list, quoted as published.

Notes without a marker are published on I23.4 itself; “inherited from” names the category or block whose note applies here.

Excludes1 — Not Coded Here

Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Code Also

Additional codes that may be required to fully describe the encounter.

  • the presence of hypertension (I10-I1A)

Source: inherited from I20-I25

Coder workflow for I23.4

MedCoder structured workflow — derived from this code’s own official record

Before you code I23.4

  1. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with I23.4. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).

    See the official tabular notes

Choose the right path

  1. Does the documentation support a condition named in I23.4’s Excludes1 note?
    Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
    No → Continue.

    ReviewI51.1

Consider I23.4. Then review the Code Also note, and confirm the code is valid for the date of service in the Verify section.

Documentation check

The provider’s diagnostic statement
Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).
Acuity
Acute or chronic as documented; when both are documented and separate codes exist, both are reported with the acute code first (Guidelines I.B.8).

Official instructions as workflow

  • Excludes1 — check before selecting I23.4(1 note)

    Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with I23.4: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

    CompareI51.1

    See the official tabular notes · Guidelines I.A.12.a

  • Code Also — related condition(1 note)

    Coding workflow: Review the related condition when both are documented and the instruction applies. A Code Also note does not fix sequencing; the order follows the circumstances of the encounter.

    See the official tabular notes · Guidelines I.A.17

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Documentation: Both the condition I23.4 describes and a condition named in its Excludes1 note are documented for the same encounter.

Coding question: Can both codes be reported?

Path: Review the Excludes1 note and the excluded code, and look for a provider statement on whether the two conditions are related.

Reason: Excludes1 means the two are not coded together; the exception is when the record shows the conditions are unrelated to each other (Guidelines I.A.12.a).

ReviewI51.1

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Code Overview

Rupture of chordae tendineae as current complication following acute myocardial infarction is a billable ICD-10-CM diagnosis code (I23.4).

MedCoder summary Summary composed by MedCoder from this code's official ICD-10-CM record. The tabular instructional notes themselves appear verbatim below.

Indexed Clinical Terms (4)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.

Verify Before Coding

  • MCC as a secondary diagnosis (FY2026). Can raise the stay's MS-DRG severity tier.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder structured relationships — computed from published CMS and AHRQ datasets

Other codes that name I23.4 or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 1 Excludes1 note: I51.1 — Rupture of chordae tendineae, not elsewhere classified.

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

Referenced by 2 Excludes2 notes: I74 — Arterial embolism and thrombosis (via I23.-), I82 — Other venous embolism and thrombosis (via I23.-).

These codes’ tabular lists name this diagnosis as distinct — both may be reported when both are documented.

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

MCC — Major Complication or Comorbidity. Reported as a secondary diagnosis, this code raises the stay's MS-DRG severity tier — except when the principal diagnosis is one of 17 clinically related codes on its CMS exclusion list.

Named in the grouper logic of 2 MS-DRGs: DRG 306 (MDC 05), DRG 307 (MDC 05).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):CIR010 — Complications of acute myocardial infarction (default).

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same clinical process (MS-DRG)

Acts as MCC — raises the severity of other admissions. CMS groups these diagnoses into one MS-DRG principal-diagnosis exclusion process — a CC/MCC on this list never raises severity when the principal diagnosis is also on it.

I23.0 — Hemopericardium as current complication following acute myocardial infarction, I23.1 — Atrial septal defect as current complication following acute myocardial infarction, I23.2 — Ventricular septal defect as current complication following acute myocardial infarction, I23.3 — Rupture of cardiac wall without hemopericardium as current complication following acute myocardial infarction, I23.6 — Thrombosis of atrium, auricular appendage, and ventricle as current complications following acute myocardial infarction, I23.7 — Postinfarction angina, I23.8 — Other current complications following acute myocardial infarction, I27.841 — Fontan-associated lymphatic dysfunction, I27.848 — Other Fontan-associated condition, I27.849 — Fontan related circulation, unspecified, I51.0 — Cardiac septal defect, acquired, I51.1 — Rupture of chordae tendineae, not elsewhere classified, I87.8 — Other specified disorders of veins, I87.9 — Disorder of vein, unspecified, I99.8 — Other disorder of circulatory system, I99.9 — Unspecified disorder of circulatory system

Same CMS-HCC risk category (V28)

CMS maps these diagnoses to the same Hierarchical Condition Category (Unstable Angina and Other Acute Ischemic Heart Disease) for risk-adjusted payment.

I20.0 — Unstable angina, I23.0 — Hemopericardium as current complication following acute myocardial infarction, I23.1 — Atrial septal defect as current complication following acute myocardial infarction, I23.2 — Ventricular septal defect as current complication following acute myocardial infarction, I23.3 — Rupture of cardiac wall without hemopericardium as current complication following acute myocardial infarction, I23.5 — Rupture of papillary muscle as current complication following acute myocardial infarction, I23.6 — Thrombosis of atrium, auricular appendage, and ventricle as current complications following acute myocardial infarction, I23.7 — Postinfarction angina, I23.8 — Other current complications following acute myocardial infarction, I24.0 — Acute coronary thrombosis not resulting in myocardial infarction, I24.1 — Dressler's syndrome, I24.81 — Acute coronary microvascular dysfunction, I24.89 — Other forms of acute ischemic heart disease, I24.9 — Acute ischemic heart disease, unspecified, I25.110 — Atherosclerotic heart disease of native coronary artery with unstable angina pectoris, I25.700 — Atherosclerosis of coronary artery bypass graft(s), unspecified, with unstable angina pectoris, I25.710 — Atherosclerosis of autologous vein coronary artery bypass graft(s) with unstable angina pectoris, I25.720 — Atherosclerosis of autologous artery coronary artery bypass graft(s) with unstable angina pectoris, I25.730 — Atherosclerosis of nonautologous biological coronary artery bypass graft(s) with unstable angina pectoris, I25.750 — Atherosclerosis of native coronary artery of transplanted heart with unstable angina, +4 more

Related risk categories

These categories interact through CMS's HCC hierarchy — one can suppress the other's risk-adjustment weight when both are present on a claim.

Acute Myocardial Infarction

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Complications of acute myocardial infarction).

I23.0 — Hemopericardium as current complication following acute myocardial infarction, I23.1 — Atrial septal defect as current complication following acute myocardial infarction, I23.2 — Ventricular septal defect as current complication following acute myocardial infarction, I23.3 — Rupture of cardiac wall without hemopericardium as current complication following acute myocardial infarction, I23.5 — Rupture of papillary muscle as current complication following acute myocardial infarction, I23.6 — Thrombosis of atrium, auricular appendage, and ventricle as current complications following acute myocardial infarction, I23.7 — Postinfarction angina, I23.8 — Other current complications following acute myocardial infarction, I24.1 — Dressler's syndrome

Same Index main term, other category

The ICD-10-CM Index to Diseases and Injuries files this code under the main term “Rupture, ruptured”; these codes share that main term but sit in a different category of the Tabular List.

A52.01 — Syphilitic aneurysm of aorta (aorta, aortic, syphilitic), A52.05 — Other cerebrovascular syphilis (brain, aneurysm, syphilitic), B51.0 — Plasmodium vivax malaria with rupture of spleen (spleen, due to P. vivax malaria), D73.5 — Infarction of spleen (spleen, spontaneous), H31.32 — Choroidal rupture (choroid), H44.89 — Other disorders of globe (globe, nontraumatic), H72.9 — Unspecified perforation of tympanic membrane (tympanum, tympanic), I07.8 — Other rheumatic tricuspid valve diseases (tricuspid), I28.8 — Other diseases of pulmonary vessels (pulmonary, vein), I34.89 — Other nonrheumatic mitral valve disorders (mitral), I35.8 — Other nonrheumatic aortic valve disorders (aorta, aortic, valve or cusp), I37.8 — Other nonrheumatic pulmonary valve disorders (pulmonary, valve), I40.9 — Acute myocarditis, unspecified (cardiac, infectional), I51.1 — Rupture of chordae tendineae, not elsewhere classified (chordae tendineae NEC), I51.2 — Rupture of papillary muscle, not elsewhere classified (papillary muscle NEC), I60.6 — Nontraumatic subarachnoid hemorrhage from other intracranial arteries (circle of Willis), I60.8 — Other nontraumatic subarachnoid hemorrhage (meningeal artery), I71.10 — Thoracic aortic aneurysm, ruptured, unspecified (aorta, aortic, thorax, thoracic), I71.11 — Aneurysm of the ascending aorta, ruptured (aorta, aortic, ascending), I71.12 — Aneurysm of the aortic arch, ruptured (aorta, aortic, arch), +145 more

Contextual Map

Every relationship of I23.4 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run I23.4 with these 3 related codes in Claim Check

Hierarchy

Excludes1

Referenced by Excludes1 notes

Referenced by Excludes2 notes

Clinical classification (CCSR)

Risk adjustment (CMS-HCC)

  • HCC 229 — Unstable Angina and Other Acute Ischemic Heart Disease [CMS-HCC]— CMS-HCC V28 · 2026

MS-DRG Grouper

MDC crossing

  • MDC 05 — Diseases and Disorders of the Circulatory System[MDC crossing]: “Diseases and Disorders of the Circulatory System — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 17,209 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026

Index entries

  • Complication (s) (from) (of), following, acute myocardial infarction NEC, chordae tendinae rupture[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Complication (s) (from) (of), following, acute myocardial infarction NEC, rupture, chordae tendineae[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Laceration, chordae tendinae NEC, following acute myocardial infarction (current complication)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
  • Rupture, ruptured, chordae tendineae NEC, following acute myocardial infarction (current complication)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes (9)

Change history

  • FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data
CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page
Claim edits Official source data
CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page
Inpatient payment groups Official source data
CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v43 Release, file and checksum · Publisher’s page
Risk adjustment Official source data
2026 Mid-Year Final ICD-10 Mappings + Model Software (cms.gov/files/zip/2026-midyear-final-icd-10-mappings.zip, 2026-midyear-final-model-software.zip) — CMS-HCC V28, PY2026 mid-year final release Release, file and checksum · Publisher’s page
Change history and date-of-service validity Official source data
CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page
Comparisons, relationships and the contextual map MedCoder structured relationship
Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears
Summary and FAQ answers MedCoder explanation
Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Change history

  • FY2016 — October 1, 2015
    In the code set at ICD-10-CM adoption
    Rupture of chordae tendineae as current complication following acute myocardial infarction

No changes since FY2016 — additions, deletions, description changes and billable-status changes are tracked through FY2027 (effective October 1, 2026), and none are recorded for this code. Note changes are tracked from FY2027 only.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to I23.4 in its code family, with their registry titles.

View all codes in the I23 family