2027 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 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

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 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 539 through 541. 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 149 closely related codes. 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

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to A52.77: 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

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 A52.77, its category, or a range that includes it.

Applicable To 1

These notes mention A52.77.

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

Excludes1 4

These codes carry an Excludes1 note naming A52.77: they are not reported together with it, unless the two conditions are unrelated.

  • H75.0 Mastoiditis in infectious and parasitic diseases classified elsewhere
    syphilis (A52.77)
  • M02 Postinfective and reactive arthropathies
    syphilis arthritis (late) (A52.77)
  • M49 Spondylopathies in diseases classified elsewhere
    spondylitis in syphilis (acquired) (A52.77)
  • M90 Osteopathies in diseases classified elsewhere
    syphilis (late) (A52.77)

Excludes2 1

These codes carry an Excludes2 note naming A52.77: 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

Alphabetical index entries that point to this code.

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

Clinical InformationClinical

  • Tertiary Syphilis

    a stage of syphilis that occurs fifteen to thirty years after the initial infection; it can include gumma formation and cardiovascular or central nervous system involvement (neurosyphilis).

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

Questions About A52.77Overview

What is the ICD-10 code for syphilis of bone and joint?

The ICD-10-CM code for syphilis of bone and joint is A52.77 (sometimes written as A5277). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

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, 2026 through September 30, 2027.

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 541, 539, 540, with relative weights from 0.8293 to 1.9376 depending on complications. Higher weights mean higher Medicare reimbursement.

Is A52.77 a CC or MCC?

CMS lists A52.77 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 149 closely related codes in its exclusion list.

Can A52.77 be reported with N34.1?

Not as a rule. The Excludes1 note at block A50-A64, which applies to A52.77, 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).