ICD-10-CM A51 is the diagnosis code for Early 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.
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.
Understanding where A51 sits in the ICD-10-CM classification helps ensure proper coding:
No, A51 is a non-billable/non-specific code. You should use a more specific sub-code for billing and reimbursement.
A51 is the ICD-10-CM diagnosis code for "Early syphilis". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.
A51 is located in Section A50-A64 — "Infections with a predominantly sexual mode of transmission" within Chapter 1 of the ICD-10-CM Tabular List.
A51 has 7 sub-code(s) that provide more specific detail: A51.0, A51.1, A51.2, A51.3, A51.4 and more.
Use A51 when the patients documented diagnosis matches "Early syphilis" and the clinical documentation supports this level of specificity. Always verify with the latest ICD-10-CM guidelines and payer requirements.
The ICD-10-CM code for Early syphilis is A51.
No, A51 is non-billable. Use a more specific sub-code for primary diagnosis billing.
A51 is in Chapter 1 of the ICD-10-CM Tabular List.
Yes, A51 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.