All ICD10 Codes
A51Non-billable

Early syphilis

Certain Infectious and Parasitic Diseases·Infections with a predominantly sexual mode of transmission (A50-A64)·category·FY 2026

Use a more specific code (5 billable, 2 non-billable)
A51.0Primary genital syphilisA51.1Primary anal syphilisA51.2Primary syphilis of other sitesA51.3Secondary syphilis of skin and mucous membraneshas subcodesA51.4Other secondary syphilishas subcodesA51.5Early syphilis, latentA51.9Early syphilis, unspecified

CH1 Parent Instructions

Includes
  • diseases generally recognized as communicable or transmissible
Excludes1(Not coded here. Use a different code.)
  • certain localized infections - see body system-related chapters
Excludes2(Not included here. Code separately if applicable.)
  • carrier or suspected carrier of infectious disease (Z22.-)
  • infectious and parasitic diseases complicating pregnancy, childbirth and the puerperium (O98.-)
  • infectious and parasitic diseases specific to the perinatal period (P35-P39)
  • influenza and other acute respiratory infections (J00-J22)
Use Additional Code
  • code to identify resistance to antimicrobial drugs (Z16.-)

A50-A64 Parent Instructions

Excludes1(Not coded here. Use a different code.)
  • nonspecific and nongonococcal urethritis (N34.1)
  • Reiter's disease (M02.3-)
Excludes2(Not included here. Code separately if applicable.)
  • human immunodeficiency virus [HIV] disease (B20)

Clinical Hierarchy

BillableHas subcodes
CH1Certain infectious and parasitic diseases (A00-B99)
A50-A64Infections with a predominantly sexual mode of transmission (A50-A64)
A51Early syphilisNot billable
A51.0Primary genital syphilisBillable
A51.1Primary anal syphilisBillable
A51.2Primary syphilis of other sitesBillable
A51.3Secondary syphilis of skin and mucous membranesSubcodes
A51.4Other secondary syphilisSubcodes
A51.5Early syphilis, latentBillable
A51.9Early syphilis, unspecifiedBillable

MS-DRG Classification

2026

No direct MS-DRG triggers identified.