2026 ICD-10-CM Diagnosis Code A53.0Latent syphilis, unspecified as early or late

ICD-10-CM Codes›A00–B99›A50-A64›A53

ICD-10-CM A53.0
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

A53.0 is a billable ICD-10-CM diagnosis code for latent syphilis, unspecified as early or late. 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. Coders also document this condition as latent syphilis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Sexually transmitted infections (excluding HIV and hepatitis).

Code Identity

ICD-10-CM Code
A53.0
Billable Status
Yes — Valid for Submission
Code Describes
Latent syphilis, unspecified as early or late
Short Description
Latent syphilis, unspecified as early or late
Same as the full description in the CMS dataset.
Parent Code
A53
Other and unspecified syphilis

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA50-A64Infections with a predominantly sexual mode of transmission
CategoryA53Other and unspecified syphilis
This CodeA53.0Latent syphilis, unspecified as early or late

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Latent syphilis
  • Latent syphilis with positive serology
  • Syphilis test finding
  • Syphilis titer detected

Tabular List NotesGuidance

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

Inclusion Terms

  • Latent syphilis NOS
  • Positive serological reaction for syphilis

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.

    • Positive
      • serology for syphilis
    • Positive
      • VDRL
    • Positive
      • Wassermann reaction
    • Serology for syphilis
      • positive
    • Serology for syphilis
      • reactivated
    • Syphilis, syphilitic(acquired)
      • latent
    • Syphilis, syphilitic(acquired)
      • latent
        • date of infection unspecified
    • Syphilis, syphilitic(acquired)
      • latent
        • follow-up of latent syphilis
    • Syphilis, syphilitic(acquired)
      • latent
        • follow-up of latent syphilis
          • date of infection unspecified
    • Syphilis, syphilitic(acquired)
      • latent
        • positive serology (only finding)
    • Syphilis, syphilitic(acquired)
      • latent
        • positive serology (only finding)
          • date of infection unspecified

Clinical ClassificationClinical

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

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

Clinical InformationClinical

  • Early Latent Syphilis

    latent syphilis when infection was acquired less than twelve months previously.

  • Late Latent Syphilis

    latent syphilis when infection was acquired more than twelve months previously.

  • Latent Syphilis

    a stage of syphilis characterized by the serologic evidence of infection by treponema pallidum without evidence of accompanying signs or symptoms related to the disease.

Patient EducationClinical

Syphilis

Syphilis is a sexually transmitted infection (STI) caused by bacteria. It infects the genital area, lips, mouth, or anus of both men and women. You usually get syphilis from sexual contact with someone who has it. It can also pass from mother to baby during pregnancy.

Read the full article at MedlinePlus

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

Convert A53.0 to ICD-9-CMHistory

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

ICD-9-CM
097.1 Latent syphilis NOS
Exact Match The mapping is direct, with no qualifiers.

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 A53.0Overview

Is A53.0 (Other and unspecified syphilis) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report latent syphilis, unspecified as early or late on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does A53.0 group to?

When latent syphilis, unspecified as early or late is the principal diagnosis on an inpatient stay, it groups to MS-DRG 867, 868, 869, with relative weights from 0.7297 to 2.0932 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of A53.0?

Under the General Equivalence Mappings, latent syphilis, unspecified as early or late converts to ICD-9-CM 097.1 (latent syphilis NOS). The mapping is a direct match.

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.