2024 ICD-10-CM Diagnosis Code A53.9

Syphilis, unspecified

ICD-10-CM Code:
ICD-10 Code for:
Syphilis, unspecified
Is Billable?
Yes - Valid for Submission
Chronic Condition Indicator: [1]
Not chronic
Code Navigator:

Code Classification

  • Certain infectious and parasitic diseases
    • Infections with a predominantly sexual mode of transmission
      • Other and unspecified syphilis

A53.9 is a billable diagnosis code used to specify a medical diagnosis of syphilis, unspecified. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2023 through September 30, 2024.

Unspecified diagnosis codes like A53.9 are acceptable when clinical information is unknown or not available about a particular condition. Although a more specific code is preferable, unspecified codes should be used when such codes most accurately reflect what is known about a patient's condition. Specific diagnosis codes should not be used if not supported by the patient's medical record.

Approximate Synonyms

The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

  • Acquired syphilis
  • Anetoderma secondary to syphilis
  • Gingival disease caused by Treponema pallidum
  • Gingival disease due to bacteria
  • Maternal syphilis during pregnancy, childbirth and the puerperium
  • Myelitis caused by bacterium
  • Myelitis caused by Treponema pallidum
  • Oral syphilis
  • Syphilis
  • Syphilis in mother complicating childbirth
  • Syphilis test finding
  • Treponema pallidum detected by enzyme-linked immunosorbent assay

Clinical Classification

Clinical Information

  • 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.
  • 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).

Index to Diseases and Injuries References

The following annotation back-references for this diagnosis code are found in the injuries and diseases index. The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10-CM code(s).

Convert A53.9 to ICD-9-CM

  • ICD-9-CM Code: 097.9 - Syphilis NOS

Patient Education


Syphilis is a sexually transmitted disease 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.

The early stage of syphilis usually causes a single, small, painless sore. Sometimes it causes swelling in nearby lymph nodes. If you do not treat it, syphilis usually causes a non-itchy skin rash, often on your hands and feet. Many people do not notice symptoms for years. Symptoms can go away and come back.

The sores caused by syphilis make it easier to get or give someone HIV during sex. If you are pregnant, syphilis can cause complications, or you could lose your baby. In rare cases, syphilis causes serious health problems and even death.

Syphilis is easy to cure with antibiotics if you catch it early. Correct usage of latex condoms greatly reduces, but does not completely eliminate, the risk of catching or spreading syphilis. If your or your partner is allergic to latex, you can use polyurethane condoms. The most reliable way to avoid infection is to not have anal, vaginal, or oral sex.

Centers for Disease Control and Prevention

[Learn More in MedlinePlus]

Code History

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.


[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.