ICD-10 Code A51.41 – Secondary syphilitic meningitis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code A51.41 – Secondary syphilitic meningitis
What it is
Use this code for meningitis caused by secondary syphilis. It identifies central nervous system involvement occurring in the secondary stage of syphilis.
Clinical signs
Clinical features vary; refer to documentation. Findings may include headache, neck stiffness, fever, or other meningitis signs in a patient with confirmed secondary syphilis.
When to use this code
Assign A51.41 when the provider documents secondary syphilitic meningitis or syphilis-related meningeal involvement in the secondary stage. Use it when the record clearly links meningitis to secondary syphilis. Check documentation if the stage or neurologic diagnosis is unclear.
Do not use for
Do not use this code for meningitis from another cause, or for neurosyphilis without documented secondary stage involvement. If the chart only says syphilis or meningitis, check documentation.
Coding tip
Code the specific syphilis stage and neurologic manifestation as documented; do not assume secondary disease without provider support.