A52.3 ICD-10-CM Code: Neurosyphilis, unspecified
HCC Buddy Code Card
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FY 2026 Apr update / Certain infectious and parasitic diseases (A00-B99) / Infections with a predominantly sexual mode of transmission (A50-A64)
A52.3
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceNeurosyphilis, unspecified
This code describes syphilis that has spread to the nervous system (brain and spinal cord), but the specific type or stage of neurological involvement has not been identified. It indicates a serious infection affecting the central nervous system that requires treatment.
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
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Code Book Path
Inclusion Terms
Official- Gumma (syphilitic)
- Syphilis (late)
- Syphiloma
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for A52.3 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for A52.3 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for A52.3 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for A52.3 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for A52.3 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for A52.3 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 A52.3 an HCC code?
No. A52.3 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
A52.3 is the ICD-10-CM diagnosis code for neurosyphilis, unspecified. This code describes syphilis that has spread to the nervous system (brain and spinal cord), but the specific type or stage of neurological involvement has not been identified. It indicates a serious infection affecting the central nervous system that requires treatment. A52.3 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).
A52.3 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.
Use this code only when the medical record documents neurosyphilis but does not specify the type (such as general paresis, tabes dorsalis, or asymptomatic neurosyphilis); if a specific form is documented, use the more specific A52.0-A52.2 codes instead.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for A52.3 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Use this code only when the medical record documents neurosyphilis but does not specify the type (such as general paresis, tabes dorsalis, or asymptomatic neurosyphilis); if a specific form is documented, use the more specific A52.0-A52.2 codes instead
- •Verify that the patient has confirmed syphilis diagnosis and documented evidence of nervous system involvement; neurosyphilis typically requires lumbar puncture findings or neurological symptoms to support the diagnosis