2026 ICD-10-CM Diagnosis Code A52.77Syphilis of bone and joint

ICD-10-CM Codes›A00–B99›A50-A64›A52

ICD-10-CM A52.77
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

A52.77 is a billable ICD-10-CM diagnosis code for syphilis of bone and joint. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 539 through 541. Coders also document this condition as arthritis following syphilis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified bone disease and musculoskeletal deformities and Sexually transmitted infections (excluding HIV and hepatitis).

Code Identity

ICD-10-CM Code
A52.77
Billable Status
Yes — Valid for Submission
Code Describes
Syphilis of bone and joint
Short Description
Syphilis of bone and joint
Same as the full description in the CMS dataset.
Parent Code
A52.7
Other symptomatic late syphilis

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA50-A64Infections with a predominantly sexual mode of transmission
CategoryA52Late syphilis
This CodeA52.77Syphilis of bone and joint

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Arthritis following syphilis
  • Arthropathy associated with bacterial disease
  • Post-bacterial arthropathy
  • Syphilis of bone

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.

    • Arthropathy
      • in (due to)
        • syphilis (late)
    • Arthropathy
      • postinfectious NEC
        • in (due to)
          • syphilis
    • Caries
      • syphilitic
    • Dactylitis
      • syphilitic
    • Destruction, destructive
      • bone
        • syphilitic
    • Exostosis
      • syphilitic
    • Gout, gouty(acute) (attack) (flare)
      • syphilitic
    • Gout, chronic
      • syphilitic
    • Gumma(syphilitic)
      • bone
    • Hydrarthrosis
      • syphilitic (late)
    • Nodule(s), nodular
      • juxta-articular
        • syphilitic
    • Osteomyelitis(general) (infective) (localized) (neonatal) (purulent) (septic) (staphylococcal) (streptococcal) (suppurative) (with periostitis)
      • syphilitic
    • Periostitis(albuminosa) (circumscribed) (diffuse) (infective) (monomelic)
      • syphilitic
    • Syphilis, syphilitic(acquired)
      • bone
    • Syphilis, syphilitic(acquired)
      • destruction of bone
    • Syphilis, syphilitic(acquired)
      • fracture
    • Syphilis, syphilitic(acquired)
      • joint (late)
    • Syphilis, syphilitic(acquired)
      • middle ear
    • Syphilis, syphilitic(acquired)
      • osseous (late)
    • Syphilis, syphilitic(acquired)
      • osteoporosis
    • Syphilis, syphilitic(acquired)
      • periosteum (late)
    • Syphilis, syphilitic(acquired)
      • petrous bone (late)
    • Syphilis, syphilitic(acquired)
      • skeletal system
    • Syphilis, syphilitic(acquired)
      • spondylitis

Clinical ClassificationClinical

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

CCSR MUS028
Other specified bone disease and musculoskeletal deformities
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

Bone Infections

Like other parts of the body, bones can get infected. The infections are usually bacterial, but can also be fungal. They may spread to the bone from nearby skin or muscles, or from another part of the body through the bloodstream.

Read the full article at MedlinePlus

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

Convert A52.77 to ICD-9-CMHistory

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

ICD-9-CM
095.5 Syphilis of bone
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 A52.77Overview

Is A52.77 (Other symptomatic late syphilis) a billable code?

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

What MS-DRG does A52.77 group to?

When syphilis of bone and joint is the principal diagnosis on an inpatient stay, it groups to MS-DRG 539, 540, 541, with relative weights from 0.7715 to 1.9697 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of A52.77?

Under the General Equivalence Mappings, syphilis of bone and joint converts to ICD-9-CM 095.5 (syphilis of bone). 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.