2026 ICD-10-CM Diagnosis Code A18.84Tuberculosis of heart

ICD-10-CM CodesA00–B99A15-A19A18

ICD-10-CM A18.84
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

A18.84 is a billable ICD-10-CM diagnosis code for tuberculosis of heart. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 867 through 869, 974 through 976. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Endocarditis and endocardial disease and Tuberculosis.

Code Identity

ICD-10-CM Code
A18.84
Billable Status
Yes — Valid for Submission
Code Describes
Tuberculosis of heart
Short Description
Tuberculosis of heart
Same as the full description in the CMS dataset.
Parent Code
Tuberculosis of other specified organs

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA15-A19Tuberculosis
CategoryA18Tuberculosis of other organs
This CodeA18.84Tuberculosis of heart

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Acute bacterial pericarditis
  • Acute myocarditis - tuberculous
  • Acute tuberculous pericarditis
  • Constrictive pericarditis
  • Constrictive pericarditis caused by bacteria
  • Constrictive pericarditis caused by Mycobacterium tuberculosis complex
  • Infective constrictive pericarditis
  • Pericarditis with pericardial effusion caused by Mycobacterium tuberculosis complex
  • Tuberculosis of endocardium
  • Tuberculosis of heart
  • Tuberculosis of mediastinum
  • Tuberculosis of myocardium
  • Tuberculosis of pericardium

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Tuberculous cardiomyopathy
  • Tuberculous endocarditis
  • Tuberculous myocarditis
  • Tuberculous pericarditis

Index to Diseases and InjuriesGuidance

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Adhesions, adhesive(postinfective)
      • pericardium (nonrheumatic)
        • tuberculous
    • Cardiomyopathy(familial) (idiopathic)
      • tuberculous
    • Myocarditis(with arteriosclerosis)(chronic)(fibroid) (interstitial) (old) (progressive) (senile)
      • tuberculous
    • Pericarditis(with decompensation) (with effusion)
      • fibrinocaseous (tuberculous)
    • Pericarditis(with decompensation) (with effusion)
      • tuberculous
    • Tuberculosis, tubercular, tuberculous(calcification) (calcified) (caseous) (chromogenic acid-fast bacilli) (degeneration) (fibrocaseous) (fistula) (interstitial) (isolated circumscribed lesions) (necrosis) (parenchymatous) (ulcerative)
      • adherent pericardium
    • Tuberculosis, tubercular, tuberculous(calcification) (calcified) (caseous) (chromogenic acid-fast bacilli) (degeneration) (fibrocaseous) (fistula) (interstitial) (isolated circumscribed lesions) (necrosis) (parenchymatous) (ulcerative)
      • cardiomyopathy
    • Tuberculosis, tubercular, tuberculous(calcification) (calcified) (caseous) (chromogenic acid-fast bacilli) (degeneration) (fibrocaseous) (fistula) (interstitial) (isolated circumscribed lesions) (necrosis) (parenchymatous) (ulcerative)
      • endocarditis
    • Tuberculosis, tubercular, tuberculous(calcification) (calcified) (caseous) (chromogenic acid-fast bacilli) (degeneration) (fibrocaseous) (fistula) (interstitial) (isolated circumscribed lesions) (necrosis) (parenchymatous) (ulcerative)
      • endocarditis
        • aortic
    • Tuberculosis, tubercular, tuberculous(calcification) (calcified) (caseous) (chromogenic acid-fast bacilli) (degeneration) (fibrocaseous) (fistula) (interstitial) (isolated circumscribed lesions) (necrosis) (parenchymatous) (ulcerative)
      • endocarditis
        • mitral
    • Tuberculosis, tubercular, tuberculous(calcification) (calcified) (caseous) (chromogenic acid-fast bacilli) (degeneration) (fibrocaseous) (fistula) (interstitial) (isolated circumscribed lesions) (necrosis) (parenchymatous) (ulcerative)
      • endocarditis
        • pulmonary
    • Tuberculosis, tubercular, tuberculous(calcification) (calcified) (caseous) (chromogenic acid-fast bacilli) (degeneration) (fibrocaseous) (fistula) (interstitial) (isolated circumscribed lesions) (necrosis) (parenchymatous) (ulcerative)
      • endocarditis
        • tricuspid
    • Tuberculosis, tubercular, tuberculous(calcification) (calcified) (caseous) (chromogenic acid-fast bacilli) (degeneration) (fibrocaseous) (fistula) (interstitial) (isolated circumscribed lesions) (necrosis) (parenchymatous) (ulcerative)
      • heart
    • Tuberculosis, tubercular, tuberculous(calcification) (calcified) (caseous) (chromogenic acid-fast bacilli) (degeneration) (fibrocaseous) (fistula) (interstitial) (isolated circumscribed lesions) (necrosis) (parenchymatous) (ulcerative)
      • myocardium, myocarditis
    • Tuberculosis, tubercular, tuberculous(calcification) (calcified) (caseous) (chromogenic acid-fast bacilli) (degeneration) (fibrocaseous) (fistula) (interstitial) (isolated circumscribed lesions) (necrosis) (parenchymatous) (ulcerative)
      • pericardium, pericarditis

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR CIR004
Endocarditis and endocardial disease
Default principal diagnosis: inpatient No · outpatient No
CCSR INF001
Tuberculosis
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Heart Diseases

Heart disease is a general term that includes many types of heart problems. It's a type of cardiovascular disease, which means heart and blood vessel disease.

The full article covers:

  • What is heart disease?
  • What are the types of heart disease?
  • What causes heart diseases?
  • Who is more likely to develop heart diseases?
  • What are the symptoms of heart disease?
  • How are heart diseases diagnosed?
  • What are the treatments for heart disease?
  • Can heart diseases be prevented?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert A18.84 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
017.90 TB of organ NEC-unspec
Approximate The match is approximate rather than exact.
ICD-9-CM
017.90 TB of organ NEC-unspec
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.
ICD-9-CM
420.0 Ac pericardit in oth dis
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.
ICD-9-CM
422.0 Ac myocardit in oth dis
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.
ICD-9-CM
424.91 Endocarditis in oth dis
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.
ICD-9-CM
425.8 Cardiomyopath in oth dis
ApproximateCombination The match is approximate, and more than one code can be needed to describe the source diagnosis. Confirm with contextual judgment.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About A18.84Overview

Is A18.84 (Tuberculosis of other specified organs) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report tuberculosis of heart on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does A18.84 group to?

When tuberculosis of heart is the principal diagnosis on an inpatient stay, it groups to MS-DRG 867, 868, 869, 974, 975, 976, with relative weights from 0.7297 to 2.8860 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of A18.84?

Under the General Equivalence Mappings, tuberculosis of heart converts to ICD-9-CM 017.90 (TB of organ NEC-unspec), 017.90 (TB of organ NEC-unspec), and 420.0 (ac pericardit in oth dis). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.