A50.59 ICD-10-CM Code: Other late congenital syphilis, symptomatic
HCC Buddy Code Card
Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.
FY 2026 Apr update / Certain infectious and parasitic diseases (A00-B99) / Infections with a predominantly sexual mode of transmission (A50-A64)
A50.59
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceOther late congenital syphilis, symptomatic
This code describes syphilis that was passed from mother to child before birth and is now causing symptoms in the child after age 2 years, but doesn't fit into other specific late congenital syphilis categories. It represents the long-term effects of untreated maternal syphilis infection during pregnancy.
CMS-HCC V28
00
RAF 0
CMS-HCC V24
00
RAF 0
ACA/HHS
00
RAF 0
ESRD/PACE
00
RAF 0
RXHCC
00
RAF 0
Code Trumping
Basket needed
Code Book Path
Inclusion Terms
Official- Any congenital syphilitic condition specified as late or manifest two years or more after birth.
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for A50.59 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for A50.59 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for A50.59 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for A50.59 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for A50.59 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for A50.59 in this effective period.
Buddy Documentation Tip
Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.
Is A50.59 an HCC code?
No. A50.59 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
A50.59 is the ICD-10-CM diagnosis code for other late congenital syphilis, symptomatic. This code describes syphilis that was passed from mother to child before birth and is now causing symptoms in the child after age 2 years, but doesn't fit into other specific late congenital syphilis categories. It represents the long-term effects of untreated maternal syphilis infection during pregnancy. A50.59 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).
A50.59 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.
Verify the patient's age is at least 2 years old, as this is classified as 'late' congenital syphilis; early congenital syphilis (A50.0-A50.2) applies to symptoms appearing before age 2.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for A50.59 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Verify the patient's age is at least 2 years old, as this is classified as 'late' congenital syphilis; early congenital syphilis (A50.0-A50.2) applies to symptoms appearing before age 2
- •Use this code only when the specific manifestation of late congenital syphilis is not captured by more specific codes (A50.30-A50.57), such as when multiple or atypical symptoms are present