Early syphilis (A51) ICD-10-CM
The A51 code range covers early syphilis with 18 ICD-10-CM diagnosis codes. 15 of them are billable and valid for claim submission in fiscal year 2027, and the category headers group them but cannot themselves be billed.
Codes in the A51 Range 18 codes · 15 billable
- A51 Early syphilisNon-billable
- A51.0 Primary genital syphilis
- A51.1 Primary anal syphilis
- A51.2 Primary syphilis of other sites
- A51.3 Secondary syphilis of skin and mucous membranesNon-billable
- A51.31 Condyloma latum
- A51.32 Syphilitic alopecia
- A51.39 Other secondary syphilis of skin
- A51.4 Other secondary syphilisNon-billable
- A51.41 Secondary syphilitic meningitis
- A51.42 Secondary syphilitic female pelvic disease
- A51.43 Secondary syphilitic oculopathy
- A51.44 Secondary syphilitic nephritis
- A51.45 Secondary syphilitic hepatitis
- A51.46 Secondary syphilitic osteopathy
- A51.49 Other secondary syphilitic conditions
- A51.5 Early syphilis, latent
- A51.9 Early syphilis, unspecified
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the A51 range.
Chancre
The primary sore of syphilis, a painless indurated, eroded papule, occurring at the site of entry of the infection.
About the A51 Code Range
Early syphilis appears here among infections that spread predominantly through sexual contact. Its codes distinguish primary and secondary forms, along with latent and unspecified early syphilis.
Primary syphilis is organized by genital, anal, or other sites. Secondary syphilis separates skin and mucous membrane conditions from other conditions. The skin branch includes named forms and other skin conditions; the other branch includes conditions involving the female pelvis, eyes, kidneys, liver, and bones. A51.5 identifies latent early syphilis, while A51.9 leaves the form unspecified.
Questions About This Page
How many billable codes are in the A51 range?
Of the 18 codes in this range, 15 are billable and valid for claim submission from October 1, 2026 through September 30, 2027. Category header codes group them but cannot be reported on claims.
What does the A51 range classify?
The range classifies early syphilis. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2027 ICD-10-CM Tabular List and order file, effective October 1, 2026 through September 30, 2027.
