A51.9 Early syphilis, unspecified

Billable ICD-10-CM code, FY2026.

MS-DRG index

Defines the logic of DRG(s) 867-869 in MDC 18.

Approximate ICD-9-CM (GEMs)

• 092.9 Early syphilis, latent, unspecified (approximate)

Code annotations containing back-references to A51.9

Back-references to A51

• Type 2 Excludes: N34 Urethritis and urethral syndrome ("urethritis in diseases with a predominantly sexual mode of transmission (A50-A64)")

Diagnosis Index entries for A51.9

• Syphilis, syphilitic (acquired) › age under 2 years NOS › acquired
• Syphilis, syphilitic (acquired) › early
• Syphilis, syphilitic (acquired) › early › relapse (treated, untreated)
• Syphilis, syphilitic (acquired) › early › symptomatic
• Syphilis, syphilitic (acquired) › recently acquired, symptomatic

Nearby codes

• 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 (this code)