A50.40 ICD-10-CM Code: Late congenital neurosyphilis, unspecified

A50.40 is the ICD-10-CM diagnosis code for late congenital neurosyphilis, unspecified. This code describes syphilis that was passed from mother to child before birth and is now causing problems with the nervous system, but the specific type of nerve damage is not specified. It typically appears years or decades after birth when the infection damages the brain, spinal cord, or nerves. A50.40 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).

A50.40 has no mapping under the current CMS-HCC V28 community payment model. A50.40 also appears in the HHS-HCC commercial risk model (HCC 003 (HHS-HCC 003 adult, RAF varies by metal level)), which is a commercial market model rather than a Medicare Advantage payment mapping. Do not assign V28 risk adjustment value from this page; verify the applicable model and payment year before using this code for risk adjustment.

Verify documentation specifies 'late' congenital neurosyphilis (typically occurring after age 2) rather than early congenital syphilis to ensure correct code selection.