ICD-10 Code A53 – Other and unspecified syphilis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code A53 – Other and unspecified syphilis
What it is
A53 is used for syphilis when the record does not specify a more exact stage or form, or when the documentation describes another syphilis type not separately coded. It is a broad category, so you should verify the note carefully.
Clinical signs
Clinical features vary; refer to documentation. Syphilis may present with skin or mucosal lesions, rash, lymphadenopathy, or neurologic or cardiovascular findings depending on stage.
When to use this code
Use A53 when the provider documents syphilis but does not identify primary, secondary, latent, congenital, or another specific category. It also fits cases described as other or unspecified syphilis in the assessment or final diagnosis. Check documentation for the stage before assigning this code.
Do not use for
Do not use A53 if the record clearly identifies a specific syphilis stage or congenital syphilis. Do not use it for a suspected infection without confirmation unless the encounter rules support that coding.
Coding tip
Look for the documented stage first; if it is stated, code the more specific syphilis code instead of A53.