ICD-10 Code A51

Early syphilis

Version 2019 Non-Billable Code
ICD-10: A51
Short Description:Early syphilis
Long Description:Early syphilis

Not Valid for Submission

ICD-10 A51 is a "header" nonspecific and non-billable code code, consider using a code with a higher level of specificity for a diagnosis of early syphilis. The code is NOT valid for the year 2019 for the submission of HIPAA-covered transactions.

Consider the following ICD-10 codes with a higher level of specificity:

  • A51.0 - Primary genital syphilis
  • A51.1 - Primary anal syphilis
  • A51.2 - Primary syphilis of other sites
  • A51.3 - Secondary syphilis of skin and mucous membranes
  • A51.31 - Condyloma latum
  • A51.32 - Syphilitic alopecia
  • A51.39 - Other secondary syphilis of skin
  • A51.4 - Other secondary syphilis
  • A51.41 - Secondary syphilitic meningitis
  • A51.42 - Secondary syphilitic female pelvic disease
  • A51.43 - Secondary syphilitic oculopathy
  • A51.44 - Secondary syphilitic nephritis
  • A51.45 - Secondary syphilitic hepatitis
  • A51.46 - Secondary syphilitic osteopathy
  • A51.49 - Other secondary syphilitic conditions
  • A51.5 - Early syphilis, latent
  • A51.9 - Early syphilis, unspecified

Code Classification

  • Certain infectious and parasitic diseases (A00–B99)
    • Infections with a predominantly sexual mode of transmission (A50-A64)
      • Early syphilis (A51)

Information for Patients


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. The most reliable way to avoid infection is to not have anal, vaginal, or oral sex.

Centers for Disease Control and Prevention

  • Condom Fact Sheet in Brief (Centers for Disease Control and Prevention)
  • Congenital syphilis (Medical Encyclopedia)
  • CSF-VDRL test (Medical Encyclopedia)
  • FTA-ABS test (Medical Encyclopedia)
  • Neurosyphilis (Medical Encyclopedia)
  • RPR test (Medical Encyclopedia)
  • Syphilis (Centers for Disease Control and Prevention)
  • Syphilis - primary (Medical Encyclopedia)
  • Syphilis and MSM (Men Who Have Sex with Men) (Centers for Disease Control and Prevention)
  • VDRL test (Medical Encyclopedia)

[Learn More]

ICD-10 Footnotes

General Equivalence Map Definitions
The ICD-10 and ICD-9 GEMs are used to facilitate linking between the diagnosis codes in ICD-9-CM and the new ICD-10-CM code set. The GEMs are the raw material from which providers, health information vendors and payers can derive specific applied mappings to meet their needs.

  • Approximate Flag - The approximate flag is on, indicating that the relationship between the code in the source system and the code in the target system is an approximate equivalent.
  • No Map Flag - The no map flag indicates that a code in the source system is not linked to any code in the target system.
  • Combination Flag - The combination flag indicates that more than one code in the target system is required to satisfy the full equivalent meaning of a code in the source system.