2026 ICD-10-CM Diagnosis Code A51.32Syphilitic alopecia

ICD-10-CM Codes›A00–B99›A50-A64›A51

ICD-10-CM A51.32
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

A51.32 is a billable ICD-10-CM diagnosis code for syphilitic alopecia. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 606 through 607. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified skin disorders and Sexually transmitted infections (excluding HIV and hepatitis).

Code Identity

ICD-10-CM Code
A51.32
Billable Status
Yes — Valid for Submission
Code Describes
Syphilitic alopecia
Short Description
Syphilitic alopecia
Same as the full description in the CMS dataset.
Parent Code
A51.3
Secondary syphilis of skin and mucous membranes

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA50-A64Infections with a predominantly sexual mode of transmission
CategoryA51Early syphilis
This CodeA51.32Syphilitic alopecia

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Syphilitic alopecia

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.

    • Alopecia(hereditaria) (seborrheica)
      • specific (syphilitic)
    • Alopecia(hereditaria) (seborrheica)
      • syphilitic (secondary)
    • Syphilis, syphilitic(acquired)
      • alopecia (secondary)

Clinical ClassificationClinical

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

CCSR SKN007
Other specified and unspecified skin disorders
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

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Read the full article at MedlinePlus

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

Convert A51.32 to ICD-9-CMHistory

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

ICD-9-CM
091.82 Syphilitic alopecia
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 A51.32Overview

Is A51.32 (Secondary syphilis of skin and mucous membranes) a billable code?

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

What MS-DRG does A51.32 group to?

When syphilitic alopecia is the principal diagnosis on an inpatient stay, it groups to MS-DRG 606, 607, with relative weights from 0.9064 to 1.5132 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of A51.32?

Under the General Equivalence Mappings, syphilitic alopecia converts to ICD-9-CM 091.82 (syphilitic alopecia). 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.