A51.4
Non-Billable

Other secondary syphilis

Non-Billable / Non-Specific Code

What is Other secondary syphilis?

ICD-10-CM A51.4 is the diagnosis code for Other secondary syphilis. This code falls under the section "Infections with a predominantly sexual mode of transmission" within Chapter 1 — Certain infectious and parasitic diseases (A00-B99). It is a non-billable/non-specific ICD-10-CM code that should not be used for reimbursement. A more specific sub-code is required for billing. Medical coders and healthcare providers use this code to document and classify diagnoses in electronic health records, insurance claims, and clinical databases.

Coding Guidelines for A51.4

Always refer to the official ICD-10-CM Tabular List for complete coding guidelines. Ensure documentation supports the specificity of the code selected. When in doubt, consult a certified medical coder or the latest CMS guidelines.

ICD-10-CM Code Hierarchy

Understanding where A51.4 sits in the ICD-10-CM classification helps ensure proper coding:

Sub-Codes 7 entries
A51.41Secondary syphilitic meningitisBillableA51.42Secondary syphilitic female pelvic diseaseBillableA51.43Secondary syphilitic oculopathyBillableA51.44Secondary syphilitic nephritisBillableA51.45Secondary syphilitic hepatitisBillableA51.46Secondary syphilitic osteopathyBillableA51.49Other secondary syphilitic conditionsBillable
Related Codes

Frequently Asked Questions

Is A51.4 a billable ICD-10-CM code?

No, A51.4 is a non-billable/non-specific code. You should use a more specific sub-code for billing and reimbursement.

What does A51.4 mean?

A51.4 is the ICD-10-CM diagnosis code for "Other secondary syphilis". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.

What is the parent code of A51.4?

The parent code of A51.4 is A51 ("Early syphilis"). A51.4 provides a more specific classification within this category.

What section is A51.4 in?

A51.4 is located in Section A50-A64 — "Infections with a predominantly sexual mode of transmission" within Chapter 1 of the ICD-10-CM Tabular List.

What are the sub-codes of A51.4?

A51.4 has 7 sub-code(s) that provide more specific detail: A51.41, A51.42, A51.43, A51.44, A51.45 and more.

When should I use A51.4?

Use A51.4 when the patients documented diagnosis matches "Other secondary syphilis" and the clinical documentation supports this level of specificity. Always verify with the latest ICD-10-CM guidelines and payer requirements.

People Also Ask

What is the ICD-10 code for Other secondary syphilis?

The ICD-10-CM code for Other secondary syphilis is A51.4.

Can A51.4 be used for primary diagnosis?

No, A51.4 is non-billable. Use a more specific sub-code for primary diagnosis billing.

What chapter is A51.4 in?

A51.4 is in Chapter 1 of the ICD-10-CM Tabular List.

Is A51.4 valid for 2026?

Yes, A51.4 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.

See Also

← PreviousA51.39Other secondary syphilis of skinNext →A51.41Secondary syphilitic meningitis
Code Details
A51.4
Other secondary syphilis
Non-Billable / Non-Specific Code
1 — Certain infectious and parasitic diseases (A00-B99)
A50-A64 — Infections with a predominantly sexual mode of transmission
2026 ICD-10-CM