2026 ICD-10-CM Diagnosis Code A52.03Syphilitic endocarditis

ICD-10-CM CodesA00–B99A50-A64A52

ICD-10-CM A52.03
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

A52.03 is a billable ICD-10-CM diagnosis code for syphilitic endocarditis. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 288 through 290. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Endocarditis and endocardial disease and Sexually transmitted infections (excluding HIV and hepatitis).

Code Identity

ICD-10-CM Code
A52.03
Billable Status
Yes — Valid for Submission
Code Describes
Syphilitic endocarditis
Short Description
Syphilitic endocarditis
Same as the full description in the CMS dataset.
Parent Code
Cardiovascular and cerebrovascular syphilis

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA50-A64Infections with a predominantly sexual mode of transmission
CategoryA52Late syphilis
This CodeA52.03Syphilitic endocarditis

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Infective endocarditis of aortic valve
  • Infective endocarditis of mitral valve
  • Infective endocarditis of pulmonary valve
  • Inflammation of aortic valve
  • Late syphilitic pulmonary regurgitation
  • Syphilis of mitral valve
  • Syphilis of pulmonary valve
  • Syphilis of tricuspid valve
  • Syphilitic aortic stenosis
  • Syphilitic endocarditis
  • Syphilitic endocarditis of aortic valve
  • Syphilitic endocarditis of mitral valve
  • Syphilitic endocarditis of pulmonary valve
  • Syphilitic endocarditis of tricuspid valve
  • Syphilitic valve disease
  • Syphilitic valvular endocarditis

Tabular List NotesGuidance

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

Inclusion Terms

  • Syphilitic aortic valve incompetence or stenosis
  • Syphilitic mitral valve stenosis
  • Syphilitic pulmonary valve regurgitation

Index to Diseases and InjuriesGuidance

External Cause of Injuries IndexGuidance

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

    • Disease, diseased
      • coronary (artery)
        • ostial, syphilitic (aortic) (mitral) (pulmonary)
    • Disease, diseased
      • heart (organic)
        • syphilitic
          • aortic
    • Endocarditis(chronic) (marantic) (nonbacterial) (thrombotic) (valvular)
      • aortic (heart) (nonrheumatic) (valve)
        • syphilitic
    • Endocarditis(chronic) (marantic) (nonbacterial) (thrombotic) (valvular)
      • pulmonary (chronic) (heart) (valve)
        • syphilitic
    • Endocarditis(chronic) (marantic) (nonbacterial) (thrombotic) (valvular)
      • syphilitic
    • Insufficiency, insufficient
      • aortic (valve)
        • syphilitic
    • Regurgitation
      • pulmonary (valve) (heart)
        • syphilitic
    • Stenosis, stenotic(cicatricial)
      • aortic (valve)
        • syphilitic
    • Stenosis, stenotic(cicatricial)
      • mitral (chronic) (inactive) (valve)
        • syphilitic
    • Syphilis, syphilitic(acquired)
      • aortic (insufficiency) (regurgitation) (stenosis)
    • Syphilis, syphilitic(acquired)
      • endocarditis
    • Syphilis, syphilitic(acquired)
      • endocarditis
        • aortic
    • Syphilis, syphilitic(acquired)
      • endocarditis
        • pulmonary
    • Syphilis, syphilitic(acquired)
      • heart (block) (decompensation) (disease) (failure)
        • valve NEC
    • Syphilis, syphilitic(acquired)
      • mitral stenosis
    • Syphilis, syphilitic(acquired)
      • valvulitis NEC

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 INF010
Sexually transmitted infections (excluding HIV and hepatitis)
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Endocarditis

Endocarditis is sometimes called infective endocarditis. It's a rare but life-threatening inflammation of the lining inside your heart's chambers and valves (the endocardium).

The full article covers:

  • What is endocarditis?
  • What causes endocarditis?
  • Who is more likely to develop endocarditis?
  • What are the symptoms of endocarditis?
  • What other problems can endocarditis cause?
  • How is endocarditis diagnosed?
  • What are the treatments for endocarditis?
  • Can endocarditis be prevented?

Read the full article at MedlinePlus

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

Convert A52.03 to ICD-9-CMHistory

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

ICD-9-CM
093.20 Syphil endocarditis NOS
Approximate The match is approximate rather than exact.
ICD-9-CM
093.21 Syphilitic mitral valve
Approximate The match is approximate rather than exact.
ICD-9-CM
093.22 Syphilitic aortic valve
Approximate The match is approximate rather than exact.
ICD-9-CM
093.23 Syphil tricuspid valve
Approximate The match is approximate rather than exact.
ICD-9-CM
093.24 Syphil pulmonary valve
Approximate The match is approximate rather than exact.

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 A52.03Overview

Is A52.03 (Cardiovascular and cerebrovascular syphilis) a billable code?

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

What MS-DRG does A52.03 group to?

When syphilitic endocarditis is the principal diagnosis on an inpatient stay, it groups to MS-DRG 288, 289, 290, with relative weights from 0.9297 to 2.7062 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of A52.03?

Under the General Equivalence Mappings, syphilitic endocarditis converts to ICD-9-CM 093.20 (syphil endocarditis NOS), 093.21 (syphilitic mitral valve), and 093.22 (syphilitic aortic valve). 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.