2026 ICD-10-CM Diagnosis Code A51.43Secondary syphilitic oculopathy

ICD-10-CM Codes›A00–B99›A50-A64›A51

ICD-10-CM A51.43
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

A51.43 is a billable ICD-10-CM diagnosis code for secondary syphilitic oculopathy. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 124 through 125. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified eye disorders and Sexually transmitted infections (excluding HIV and hepatitis).

Code Identity

ICD-10-CM Code
A51.43
Billable Status
Yes — Valid for Submission
Code Describes
Secondary syphilitic oculopathy
Short Description
Secondary syphilitic oculopathy
Same as the full description in the CMS dataset.
Parent Code
A51.4
Other secondary syphilis

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA50-A64Infections with a predominantly sexual mode of transmission
CategoryA51Early syphilis
This CodeA51.43Secondary syphilitic oculopathy

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Bilateral iritis due to secondary syphilis
  • Bilateral iritis of eyes caused by Treponema pallidum
  • Bilateral retinitis of eyes caused by Treponema pallidum
  • Chorioretinitis due to secondary syphilis
  • Chorioretinitis of bilateral eyes due to secondary syphilis
  • Chorioretinitis of left eye due to secondary syphilis
  • Chorioretinitis of right eye due to secondary syphilis
  • Infectious secondary iridocyclitis
  • Infectious secondary iritis
  • Iritis of left eye caused by Treponema pallidum
  • Iritis of right eye caused by Treponema pallidum
  • Left iritis due to secondary syphilis
  • Left syphilitic retinitis
  • Posterior uveitis due to infectious disease
  • Retinitis of bilateral eyes due to secondary syphilis
  • Retinitis of eye due to secondary syphilis
  • Right iritis due to secondary syphilis
  • Right syphilitic retinitis
  • Secondary syphilis of eye
  • Secondary syphilitic iridocyclitis
  • Syphilitic chorioretinitis
  • Syphilitic choroiditis
  • Syphilitic disseminated retinochoroiditis
  • Syphilitic infectious intermediate uveitis
  • Syphilitic iritis
  • Syphilitic retinitis
  • Uveitis due to secondary syphilis

Tabular List NotesGuidance

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

Inclusion Terms

  • Secondary syphilitic chorioretinitis
  • Secondary syphilitic iridocyclitis, iritis
  • Secondary syphilitic uveitis

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

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

    • Chorioretinitis
      • in (due to)
        • syphilis (secondary)
    • Chorioretinitis
      • syphilitic (secondary)
    • Iridocyclitis
      • in (due to)
        • syphilis
    • Iridocyclitis
      • syphilitic (secondary)
    • Iritis
      • syphilitic (secondary)
    • Oculopathy
      • syphilitic NEC
        • early (secondary)
    • Retinitis
      • syphilitic (early) (secondary)
    • Syphilis, syphilitic(acquired)
      • chorioretinitis
    • Syphilis, syphilitic(acquired)
      • ciliary body (secondary)
    • Syphilis, syphilitic(acquired)
      • iris, iritis (secondary)
    • Syphilis, syphilitic(acquired)
      • secondary (and primary)
        • chorioretinitis, choroiditis
    • Syphilis, syphilitic(acquired)
      • uveal tract (secondary)
    • Syphilis, syphilitic(acquired)
      • uveitis (secondary)
    • Uveitis(anterior)
      • syphilitic (secondary)

Clinical ClassificationClinical

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

CCSR EYE012
Other specified eye disorders
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

  • Secondary Syphilis

    the secondary stage of syphilis typically that is characterized by generalized rash (including palms and soles), mucocutaneous lesions, and lymphadenopathy. it usually begins one to two months after the primary stage.

Patient EducationClinical

Eye Infections

Your eyes can get infections from bacteria, fungi, or viruses. Eye infections can occur in different parts of the eye and can affect just one eye or both. Two common eye infections are:

Read the full article at MedlinePlus

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

Convert A51.43 to ICD-9-CMHistory

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

ICD-9-CM
091.50 Syphilitic uveitis NOS
Approximate The match is approximate rather than exact.
ICD-9-CM
091.51 Syphilit chorioretinitis
Approximate The match is approximate rather than exact.
ICD-9-CM
091.52 Syphilitic iridocyclitis
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 A51.43Overview

Is A51.43 (Other secondary syphilis) a billable code?

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

What MS-DRG does A51.43 group to?

When secondary syphilitic oculopathy is the principal diagnosis on an inpatient stay, it groups to MS-DRG 124, 125, with relative weights from 0.7678 to 1.3231 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of A51.43?

Under the General Equivalence Mappings, secondary syphilitic oculopathy converts to ICD-9-CM 091.50 (syphilitic uveitis NOS), 091.51 (syphilit chorioretinitis), and 091.52 (syphilitic iridocyclitis). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.