2026 ICD-10-CM Diagnosis Code A50.2Early congenital syphilis, unspecified

ICD-10-CM CodesA00–B99A50-A64A50

ICD-10-CM A50.2
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

A50.2 is a billable ICD-10-CM diagnosis code for early congenital syphilis, unspecified. 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 early congenital syphilis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Perinatal infections and Sexually transmitted infections (excluding HIV and hepatitis).

Code Identity

ICD-10-CM Code
A50.2
Billable Status
Yes — Valid for Submission
Code Describes
Early congenital syphilis, unspecified
Short Description
Early congenital syphilis, unspecified
Same as the full description in the CMS dataset.
Parent Code
Congenital syphilis

Code Classification

ChapterA00–B99Certain infectious and parasitic diseases
SectionA50-A64Infections with a predominantly sexual mode of transmission
CategoryA50Congenital syphilis
This CodeA50.2Early congenital syphilis, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Early congenital syphilis
  • Oral syphilis
  • Syphilis

Tabular List NotesGuidance

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

Inclusion Terms

  • Congenital syphilis NOS less than two years after birth.

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.

    • Syphilis, syphilitic(acquired)
      • congenital
        • early, or less than 2 years after birth NEC

Clinical ClassificationClinical

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

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

  • Longitudinal Studies

    studies in which variables relating to an individual or group of individuals are assessed over a period of time.
  • Neurosyphilis

    infections of the central nervous system caused by treponema pallidum which present with a variety of clinical syndromes. the initial phase of infection usually causes a mild or asymptomatic meningeal reaction. the meningovascular form may present acutely as brain infarction. the infection may also remain subclinical for several years. late syndromes include general paresis; tabes dorsalis; meningeal syphilis; syphilitic optic atrophy; and spinal syphilis. general paresis is characterized by progressive dementia; dysarthria; tremor; myoclonus; seizures; and argyll-robertson pupils. (adams et al., principles of neurology, 6th ed, pp722-8)
  • Syphilis

    a contagious venereal disease caused by the spirochete treponema pallidum.
  • Syphilis Serodiagnosis

    serologic tests for syphilis.
  • Syphilis, Cardiovascular

    cardiovascular manifestations of syphilis, an infection of treponema pallidum. in the late stage of syphilis, sometimes 20-30 years after the initial infection, damages are often seen in the blood vessels including the aorta and the aortic valve. clinical signs include syphilitic aortitis, aortic insufficiency, or aortic aneurysm.
  • 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.
  • Syphilis, Cutaneous

    cutaneous lesions arising from infection with treponema pallidum. in the primary stage, 18-21 days following infection, one or more chancres appear. if untreated, the subsequent stages of the disease appear as syphilids. these eruptions are superficial, nondestructive, exanthematic, transient, macular roseolas that may later be maculopapular or papular polymorphous or scaly, pustular, pigmented eruptions.(arnold, odom, and james, andrew's diseases of the skin, 8th ed, p409)
  • Syphilis, Latent

    the stage of syphilis that occurs following the primary (chancre) and secondary stages. the patient is asymptomatic at the latent stage but remains seropositive for the spirochete.
  • Tabes Dorsalis

    parenchymatous neurosyphilis marked by slowly progressive degeneration of the posterior columns, posterior roots, and ganglia of the spinal cord. the condition tends to present 15 to 20 years after the initial infection and is characterized by lightening-like pains in the lower extremities, urinary incontinence; ataxia; severely impaired position and vibratory sense, abnormal gait (see gait disorders, neurologic), optic atrophy; argyll-robertson pupils, hypotonia, hyperreflexia, and trophic joint degeneration (charcot's joint; see arthropathy, neurogenic). (from adams et al., principles of neurology, 6th ed, p726)
  • Treponema pallidum

    the causative agent of venereal and non-venereal syphilis as well as yaws.
  • Late Latent Congenital Syphilis

    the occurrence of syphilis symptoms in individuals who were infected before or during birth and have not exhibited signs of the disease for over a year.
  • Cardiovascular Syphilis|Cardiovascular syphilis, unspecified

    complications of syphilis seen in the cardiovascular system. these may include aortitis, aortic valve insufficiency with regurgitation, coronary artery stenosis, aortic root aneurysm and mucinous myocarditis.
  • Congenital Syphilis

    a life-threatening bacterial infection of the newborn caused by treponema pallidum. it is transmitted to the infant from a mother with syphilis through the placenta during pregnancy. signs and symptoms include irritability, fever, failure to thrive, saddle nose, cutaneous rash, and pneumonia.
  • 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.
  • Nephrotic Syndrome - Syphilis Associated|Syphilis Associated Nephrotic Syndrome

    nephrotic syndrome associated with a syphilis infection.
  • Neurosyphilis

    infection of the brain or spinal cord by treponema pallidum. it occurs many years following the original infection which remained untreated. signs and symptoms include abnormal gait, blindness, depression, paralysis, seizures and dementia.
  • Other Cardiovascular Syphilis|Other cardiovascular syphilis

    evidence of other cardiovascular syphilis not specified elsewhere.
  • Primary Syphilis

    the subclinical or symptomatic stage of syphilis, occurring at an average of three weeks after contact with an infected individual. it manifests with one or more painless, indurated ulcers (chancres) of the skin or mucous membranes at the site of inoculation. these lesions heal spontaneously within a few weeks.
  • Secondary Syphilis

    the secondary stage of syphilis typically that is characterized by generalized rash (including palms and soles), mucocutaneous lesions, and lymphadenopathy. it usually begins one to two months after the primary stage.
  • Syphilis

    a contagious bacterial infection caused by the spirochete treponema pallidum. it is a sexually transmitted disorder, although it can also be transmitted from the mother to the fetus in utero. typically, it is initially manifested with a single sore which heals without treatment. if the infection is left untreated, the initial stage is followed by skin rash and mucous membrane lesions. a late stage follows, which is characterized by damage of the internal organs, including the nervous system.
  • Syphilis of Liver and Other Viscera|Syphilis of liver and Other viscera

    evidence of syphilis of liver and other viscera.
  • Tertiary Syphilis|Late 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

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 A50.2 to ICD-9-CMHistory

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

ICD-9-CM
090.2 Early congen syph 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 A50.2Overview

Is A50.2 (Congenital syphilis) a billable code?

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

What MS-DRG does A50.2 group to?

When early congenital syphilis, unspecified 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 A50.2?

Under the General Equivalence Mappings, early congenital syphilis, unspecified converts to ICD-9-CM 090.2 (early congen syph 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.