A39.9 ICD-10-CM Code: Meningococcal infection, unspecified
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) / Other bacterial diseases (A30-A49)
A39.9
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceMeningococcal infection, unspecified
A bacterial infection caused by Neisseria meningitidis (meningococcus) where the specific type or location of infection has not been determined or documented. This is a serious infection that can affect the bloodstream, brain lining, or other parts of the body.
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- Meningococcal disease NOS
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for A39.9 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for A39.9 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for A39.9 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for A39.9 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for A39.9 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for A39.9 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 A39.9 an HCC code?
No. A39.9 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.
Coder workflow notes
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This code does not map to an HCC category in any model (V28, V24, ESRD, RxHCC).
What This Code Means
A39.9 is the ICD-10-CM diagnosis code for meningococcal infection, unspecified. A bacterial infection caused by Neisseria meningitidis (meningococcus) where the specific type or location of infection has not been determined or documented. This is a serious infection that can affect the bloodstream, brain lining, or other parts of the body. A39.9 sits in the ICD-10-CM chapter for certain infectious and parasitic diseases (a00-b99), within the section covering other bacterial diseases (a30-a49).
A39.9 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 documentation does not specify the type of meningococcal infection (such as meningitis, septicemia, or arthritis); query the provider for more specific documentation to assign a more precise code from the A39 category.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for A39.9 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 documentation does not specify the type of meningococcal infection (such as meningitis, septicemia, or arthritis); query the provider for more specific documentation to assign a more precise code from the A39 category
- •This unspecified code should be avoided when possible; review the clinical notes carefully to determine if a more specific meningococcal infection code (A39.0-A39.8) can be assigned based on the patient's presentation and test results