A50.6
BillableLate congenital syphilis, latent
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is A50.6 an HCC code?
No. A50.6 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.
This code does not map to an HCC category in any model (V28, V24, ESRD, RxHCC).
What This Code Means
A50.6 is the ICD-10-CM diagnosis code for late congenital syphilis, latent. This is a late-stage syphilis infection that was passed from mother to child before birth, where the person shows no active symptoms but still carries the infection. The disease is in a dormant or hidden state, meaning it's not currently causing noticeable problems but could potentially become active later. A50.6 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).
A50.6 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 used for congenital syphilis cases diagnosed after age 2 years with no clinical manifestations; ensure documentation confirms latent status and congenital origin.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for A50.6 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This code is used for congenital syphilis cases diagnosed after age 2 years with no clinical manifestations; ensure documentation confirms latent status and congenital origin
- •Do not use this code if there are active clinical manifestations of late congenital syphilis (such as interstitial keratitis, saddle nose, or saber shins); use the appropriate manifestation-specific code instead