A50.31 ICD-10-CM Code: Late congenital syphilitic interstitial keratitis

A50.31 is the ICD-10-CM diagnosis code for late congenital syphilitic interstitial keratitis. This is an eye infection caused by syphilis that was passed from mother to child before birth, occurring years after birth and causing inflammation in the clear front part of the eye (cornea). It results in scarring and vision problems that develop later in childhood or adulthood. A50.31 sits in the ICD-10-CM chapter for certain infectious and parasitic diseases (a00-b99), within the section covering infections with a predominantly sexual mode of transmission (a50-a64).

A50.31 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.

This code is specific to late congenital syphilis manifestations; verify documentation confirms both the congenital syphilis diagnosis and the keratitis (eye inflammation) component.