2027 ICD-10-CM Diagnosis Code A50.02Early congenital syphilitic osteochondropathy

ICD-10-CM Codes›A00–B99›A50-A64›A50

ICD-10-CM A50.02
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

A50.02 is a billable ICD-10-CM diagnosis code for early congenital syphilitic osteochondropathy. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 867 through 869. 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 79 closely related codes. Coders also document this condition as arthritis caused by Spirochaetales. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified bone disease and musculoskeletal deformities, Perinatal infections, and Sexually transmitted infections (excluding HIV and hepatitis).

Code Identity

ICD-10-CM Code
A50.02
Billable Status
Yes — Valid for Submission
Code Describes
Early congenital syphilitic osteochondropathy
Short Description
Early congenital syphilitic osteochondropathy
Same as the full description in the CMS dataset.
Parent Code
A50.0
Early congenital syphilis, symptomatic

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA50-A64Infections with a predominantly sexual mode of transmission
CategoryA50Congenital syphilis
This CodeA50.02Early congenital syphilitic osteochondropathy

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Arthritis caused by Spirochaetales
  • Congenital syphilitic osteochondritis
  • Congenital syphilitic periostitis
  • Early congenital syphilis
  • Early congenital syphilis with symptoms
  • Syphilis of bone

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to A50.02: 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 A50.02, its category, or a range that includes it.

Applicable To 1

These notes mention A50.02.

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

Excludes2 3

These codes carry an Excludes2 note naming A50.02: its condition is not part of those codes, and both may be reported when the patient has both.

  • Block P35-P39 Infections specific to the perinatal period
    congenital syphilis (A50.-) names A50.-, which includes this code
  • P37 Other congenital infectious and parasitic diseases
    congenital syphilis (A50.-) names A50.-, which includes this code
  • Block A65-A69 Other spirochetal diseases
    syphilis (A50-A53) names A50-A53, which includes this code

Code First 6

These codes say to code first a condition named in the note, and A50.02 is one of the conditions named.

  • D77 Other disorders of blood and blood-forming organs in diseases classified elsewhere
    congenital early syphilis (A50.0-) names A50.0-, which includes this code
  • H94.8 Other specified disorders of ear in diseases classified elsewhere
    congenital syphilis (A50.0) names A50.0, which includes this code
  • J99 Respiratory disorders in diseases classified elsewhere
    congenital syphilis (A50.-) names A50.-, which includes this code
  • J99 Respiratory disorders in diseases classified elsewhere
    early congenital syphilis (A50.0-) names A50.0-, which includes this code
  • K67 Disorders of peritoneum in infectious diseases classified elsewhere
    congenital syphilis (A50.0) names A50.0, which includes this code
  • K77 Liver disorders in diseases classified elsewhere
    congenital syphilis (A50.0, A50.5) names A50.0, 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 PNL009
Perinatal infections
Default principal diagnosis: inpatient Yes · outpatient Yes
CCSR INF010
Sexually transmitted infections (excluding HIV and hepatitis)
Default principal diagnosis: inpatient No · outpatient No

Clinical InformationClinical

  • Syphilis, Congenital

    syphilis acquired in utero and manifested by any of several characteristic tooth (hutchinson's teeth) or bone malformations and by active mucocutaneous syphilis at birth or shortly thereafter. ocular and neurologic changes may also occur.

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 A50.02 to ICD-9-CMHistory

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

ICD-9-CM
090.0 Early cong syph symptom
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 A50.02Overview

What is the ICD-10 code for early congenital syphilitic osteochondropathy?

The ICD-10-CM code for early congenital syphilitic osteochondropathy is A50.02 (sometimes written as A5002). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is A50.02 (Early congenital syphilis, symptomatic) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report early congenital syphilitic osteochondropathy on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does A50.02 group to?

When early congenital syphilitic osteochondropathy is the principal diagnosis on an inpatient stay, it groups to MS-DRG 867, 869, 868, with relative weights from 0.6784 to 2.1855 depending on complications. Higher weights mean higher Medicare reimbursement.

Is A50.02 a CC or MCC?

CMS lists A50.02 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 79 closely related codes in its exclusion list.

Can A50.02 be reported with N34.1?

Not as a rule. The Excludes1 note at block A50-A64, which applies to A50.02, 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).