ICD10BillableValid for clinical use
ICD-10 Code A51.5: Early syphilis, latent
Reviewed by HealthAssure Clinical TeamUpdated 26 May 2026
What is this code?
ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Certain infectious and parasitic diseases (A00-B99).
When is it used?
- May be used when a clinician documents early syphilis, latent in a patient's medical record.
- May appear in hospital records, claims, referrals, and clinical documentation.
- This code can be used as a clinically usable diagnosis entry in standardized coding workflows.
What it does not mean
- A code alone does not explain severity, treatment plan, or outcome.
- A medical code should not be treated as a substitute for a doctor's diagnosis or advice.
Code hierarchy
chapter
1Certain infectious and parasitic diseases (A00-B99)
block
A50-A64Infections with a predominantly sexual mode of transmission
category
A51Early syphilis
currentA51
Official coding notes
Inclusion terms
- Syphilis (acquired) without clinical manifestations, with positive serological reaction and negative spinal fluid test, less than two years after infection.
Where you may see this code
You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records.
Related specialists
Infectious Disease SpecialistGeneral PhysicianENT Specialist
Related codes
Sibling codes
Mapped diagnoses and classifications
SNOMED_CT 266130009high
Acquired syphilis - early latent
Source: SNOMED International ICD-10 map
SNOMED_CT 31137003high
Early latent syphilis, positive serology, negative cerebrospinal fluid, less than 2 years after infection
Source: SNOMED International ICD-10 map
SNOMED_CT 1107004high
Early latent syphilis, positive serology, negative cerebrospinal fluid, with relapse after treatment
Source: SNOMED International ICD-10 map
SNOMED_CT 186867005high
Latent early syphilis
Source: SNOMED International ICD-10 map
SNOMED_CT 186868000high
Serological relapse after treatment of latent early syphilis
Source: SNOMED International ICD-10 map
Coding guidelines
Compatibility
Legacy and official ICD code match exactly.
Legacy codes
A51.5
Common synonyms
Early syphilis, latent
Frequently asked questions
About this content
This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.