ICD-10 Code A53.9 – Syphilis, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code A53.9 – Syphilis, unspecified
What it is
A53.9 identifies syphilis when the stage or specific form is not documented. Use it for confirmed syphilis cases that lack enough detail for a more specific code.
Clinical signs
Clinical features vary; refer to documentation. Syphilis may present with mucocutaneous lesions, rash, lymphadenopathy, or neurologic or cardiovascular findings depending on stage.
When to use this code
Use this code when the record states syphilis but does not identify primary, secondary, latent, or congenital disease. It is also appropriate when the provider documents syphilis without further specification. Check documentation before defaulting to this code.
Do not use for
Do not use A53.9 when the stage is documented elsewhere, such as primary, secondary, latent, or neurosyphilis. Also avoid it for congenital syphilis or a ruled-out diagnosis.
Coding tip
If the note is vague, query for the syphilis stage before assigning A53.9.