`A51.0` Primary genital syphilis

Billable ICD-10-CM code, FY2026.

MS-DRG index

Defines the logic of DRG(s) 727-728 in MDC 12.

Type 1 Excludes: N77.0 Ulceration of vulva in diseases classified elsewhere ("ulceration of vulva in syphilis (A51.0)")
Type 1 Excludes: N77.1 Vaginitis, vulvitis and vulvovaginitis in diseases classified elsewhere ("vulvovaginitis in early syphilis (A51.0)")

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

Bubo › syphilitic (primary)
Chancre (any genital site) (hard) (hunterian) (mixed) (primary) (seronegative) (seropositive) (syphilitic)
Chancre (any genital site) (hard) (hunterian) (mixed) (primary) (seronegative) (seropositive) (syphilitic) › urethra
Lesion (s) (nontraumatic) › primary
Syphilis, syphilitic (acquired) › bubo (primary)
Syphilis, syphilitic (acquired) › chancre (multiple)
Syphilis, syphilitic (acquired) › chancre (multiple) › Rollet's
Syphilis, syphilitic (acquired) › early › symptomatic › primary, except extragenital chancre
Syphilis, syphilitic (acquired) › genital (primary)
Syphilis, syphilitic (acquired) › penis (chancre)
Syphilis, syphilitic (acquired) › primary
Syphilis, syphilitic (acquired) › primary › genital
Syphilis, syphilitic (acquired) › vagina
Syphilis, syphilitic (acquired) › vulva
Ulcus › durum (syphilitic)
Vaginitis (acute) (circumscribed) (diffuse) (emphysematous) (nonvenereal) (ulcerative) › syphilitic (early)
Vulvitis (acute) (allergic) (atrophic) (hypertrophic) (intertriginous) (senile) › syphilitic (early)