A51.5 Early syphilis, latent
The ICD-10-CM code for Early syphilis, latent is A51.5 (FY2026). It is a billable, claim-ready diagnosis code.
Classification
- Section
- A50-A64: Infections with a predominantly sexual mode of transmission (A50-A64)
- Category A51
- 18 codes (15 billable)
- FY2026 Status
- Stable since FY2024
Also Known As
ICD-10-CM Alphabetic Index entries that lead to A51.5:
- Syphilis, syphilitic (acquired) › latent › early, or less than 2 years after infection
- Syphilis, syphilitic (acquired) › early › latent (without manifestations) (less than 2 years after infection)
- Syphilis, syphilitic (acquired) › early › latent (without manifestations) (less than 2 years after infection) › negative spinal fluid test
- Syphilis, syphilitic (acquired) › latent › positive serology (only finding) › early, or less than 2 years after infection
- Syphilis, syphilitic (acquired) › early › latent (without manifestations) (less than 2 years after infection) › serology positive
- Syphilis, syphilitic (acquired) › early › latent (without manifestations) (less than 2 years after infection) › serological relapse after treatment
Inclusion Terms
- Syphilis (acquired) without clinical manifestations, with positive serological reaction and negative spinal fluid test, less than two years after infection.
U.S. Hospital Utilization
- An estimated 365 U.S. inpatient stays in 2023 included A51.5 among the documented diagnoses.
Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.
Official Coding Guidelines
HIV Infections (TOC entry)a. Human Immunodeficiency Virus (HIV) Infections .............................................................. 19
Infectious agents causing diseases in other chapters (TOC)b. Infectious agents as the cause of diseases classified to other chapters ................................. 22
Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026