ICD10BillableValid for clinical use
ICD-10 Code A53.9: Syphilis, unspecified
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 syphilis, unspecified 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
A53Other and unspecified syphilis
currentA53
Official coding notes
Inclusion terms
- Infection due to Treponema pallidum NOS
- Syphilis (acquired) NOS
Excludes1 (do not code together)
- syphilis NOS under two years of age (A50.2)
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 Physician
Mapped diagnoses and classifications
SNOMED_CT 240555007high
Acquired syphilis
Source: SNOMED International ICD-10 map
SNOMED_CT 76272004high
Syphilis
Source: SNOMED International ICD-10 map
SNOMED_CT 232313005high
Endocochlear syphilis
Source: SNOMED International ICD-10 map
SNOMED_CT 713251003high
Gingival disease caused by Treponema pallidum
Source: SNOMED International ICD-10 map
Coding guidelines
Compatibility
Legacy and official ICD code match exactly.
Legacy codes
A53.9
Common synonyms
Syphilis, unspecifiedSyphilis
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.