2027 ICD-10-CM Diagnosis Code A52.03Syphilitic endocarditis

ICD-10-CM Codes›A00–B99›A50-A64›A52

ICD-10-CM A52.03
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

A52.03 is a billable ICD-10-CM diagnosis code for syphilitic endocarditis. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 288 through 290. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 96 closely related codes. 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

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to A52.03: its own notes plus those printed at block A50-A64 and Chapter 1. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From Chapter 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • diseases generally recognized as communicable or transmissible

Applicable To

Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.

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

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From Block A50-A64 Infections with a predominantly sexual mode of transmission applies to 142 codes
  • nonspecific and nongonococcal urethritis (N34.1)
  • Reiter's disease (M02.3-)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Block A50-A64 Infections with a predominantly sexual mode of transmission applies to 142 codes
  • human immunodeficiency virus [HIV] disease (B20)
From Chapter 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • carrier or suspected carrier of infectious disease (Z22.-)
  • certain localized infections - see body system-related chapters
  • infectious and parasitic diseases complicating pregnancy, childbirth and the puerperium (O98.-)
  • infectious and parasitic diseases specific to the perinatal period (P35-P39)
  • influenza and other acute respiratory infections (J00-J22)

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From Chapter 1 (A00-B99) Certain infectious and parasitic diseases applies to 1,068 codes
  • code to identify resistance to antimicrobial drugs (Z16.-)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name A52.03, its category, or a range that includes it.

Applicable To 1

These notes mention A52.03.

  • O98.1 Syphilis complicating pregnancy, childbirth and the puerperium
    Conditions in A50-A53 names A50-A53, which includes this code

Excludes1 1

These codes carry an Excludes1 note naming A52.03: they are not reported together with it, unless the two conditions are unrelated.

  • I39 Endocarditis and heart valve disorders in diseases classified elsewhere
    syphilis (A52.03)

Excludes2 1

These codes carry an Excludes2 note naming A52.03: its condition is not part of those codes, and both may be reported when the patient has both.

  • Block A65-A69 Other spirochetal diseases
    syphilis (A50-A53) names A50-A53, which includes this code

Index to Diseases and InjuriesGuidance

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

Clinical InformationClinical

  • Syphilitic Endocarditis

    endocarditis secondary to syphilis.

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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About A52.03Overview

What is the ICD-10 code for syphilitic endocarditis?

The ICD-10-CM code for syphilitic endocarditis is A52.03 (sometimes written as A5203). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

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, 2026 through September 30, 2027.

What MS-DRG does A52.03 group to?

When syphilitic endocarditis is the principal diagnosis on an inpatient stay, it groups to MS-DRG 289, 288, 290, with relative weights from 0.7843 to 2.6304 depending on complications. Higher weights mean higher Medicare reimbursement.

Is A52.03 a CC or MCC?

CMS lists A52.03 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 96 closely related codes in its exclusion list.

Can A52.03 be reported with N34.1?

Not as a rule. The Excludes1 note at block A50-A64, which applies to A52.03, lists "nonspecific and nongonococcal urethritis (N34.1)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).