A39.83 ICD-10-CM Code: Meningococcal arthritis
A39.83 maps to CMS-HCC V28 92 (RAF 0.479). Documentation must support MEAT. MEAT criteria · RAF calculator · free HCC coding tools
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FY 2026 Apr update / Certain infectious and parasitic diseases (A00-B99) / Other bacterial diseases (A30-A49)
A39.83
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceMeningococcal arthritis
This is a joint infection caused by meningococcal bacteria (Neisseria meningitidis), which can occur as a complication of meningococcal disease. The infection causes inflammation and pain in the affected joints.
Buddy Insight
Meningococcal arthritis is a septic arthritis caused by Neisseria meningitidis, occurring as a complication of meningococcal infection.
CMS-HCC V28
MappedHCC 92
RAF 0.479
CMS-HCC V24
MappedHCC 39
RAF 0.401
ACA/HHS
MappedHCC 55
Varies by metal level
ESRD/PACE
MappedHCC 39
RAF 0.092
RXHCC
N/A—
Not mapped
Code Book Path
Inclusion Terms
OfficialICD-10-CM does not list inclusion terms for A39.83 in this effective period.
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for A39.83 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for A39.83 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for A39.83 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for A39.83 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for A39.83 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for A39.83 in this effective period.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →
Is A39.83 an HCC code?
Yes. A39.83 (Meningococcal arthritis) maps to Bone/Joint/Muscle/Severe Soft Tissue Infections/Necrosis under the CMS-HCC V28 risk adjustment model (and Bone/Joint/Muscle Infections/Necrosis under V24), with a community non-dual aged RAF of 0.479. It is billable for payment year 2026.
Coder answer: A39.83 is billable and maps to V28 HCC 92, Bone/Joint/Muscle/Severe Soft Tissue Infections/Necrosis. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.
- Code
- A39.83
- Description
- Meningococcal arthritis
- HCC (V28)
- HCC 92 — Bone/Joint/Muscle/Severe Soft Tissue Infections/Necrosis
- RAF
- 0.479
- Billable
- Yes
- Payment year
- 2026
HCC Category Mapping
Each model's RAF is its CMS base weight for that model's standard population, so weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.
Work A39.83 in the Code Book — tabular path, V28 RAF, and MEAT checklist →
MEAT Criteria for A39.83
For A39.83 to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.
- MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
- EEvaluate: test results, medication response, or physical findings reviewed by the provider
- AAssess: explicit mention in the assessment or plan with acknowledgment of status
- TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis
Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed A39.83 during that encounter, not just copy-forwarded from a problem list.
Coder workflow notes
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What This Code Means
A39.83 is the ICD-10-CM diagnosis code for meningococcal arthritis. This is a joint infection caused by meningococcal bacteria (Neisseria meningitidis), which can occur as a complication of meningococcal disease. The infection causes inflammation and pain in the affected joints. A39.83 sits in the ICD-10-CM chapter for certain infectious and parasitic diseases (a00-b99), within the section covering other bacterial diseases (a30-a49).
Under the CMS-HCC V28 risk adjustment model, A39.83 maps to Bone/Joint/Muscle/Severe Soft Tissue Infections/Necrosis (HCC 92) with a community, non-dual, aged base RAF weight of 0.479. Under the older CMS-HCC V24 model, A39.83 maps to Bone/Joint/Muscle Infections/Necrosis (HCC 39) with a community, non-dual, aged base RAF weight of 0.401. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.
This code should only be used when meningococcal arthritis is documented as a manifestation of meningococcal infection; verify the causative organism is confirmed as Neisseria meningitidis. Because A39.83 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for A39.83 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This code should only be used when meningococcal arthritis is documented as a manifestation of meningococcal infection; verify the causative organism is confirmed as Neisseria meningitidis
- •Consider whether this is a secondary manifestation of meningococcemia (A39.2) or meningitis (A39.0), as the underlying meningococcal condition may need to be coded as the primary diagnosis depending on the clinical focus
Clinical Significance
Meningococcal arthritis is a septic arthritis caused by Neisseria meningitidis, occurring as a complication of meningococcal infection. It can present as a direct infectious arthritis (purulent joint) or as an immune-mediated reactive arthritis. Prompt joint drainage and antibiotic therapy are essential to prevent joint destruction.
Documentation Requirements
- ✓Confirmed meningococcal infection with documented joint involvement
- ✓Synovial fluid analysis (Gram stain, culture, cell count with differential)
- ✓Specific joint(s) affected and examination findings
- ✓Differentiation between septic (infectious) arthritis and immune-mediated reactive arthritis
- ✓Imaging of affected joints when obtained
Commonly Confused Codes
- •A39.84 (Postmeningococcal arthritis): A39.83 is active infectious arthritis during meningococcal infection; A39.84 is reactive/post-infectious arthritis occurring after the acute infection
- •M00.9 (Pyogenic arthritis, unspecified): Use A39.83 when meningococcus is the identified cause
- •A02.23 (Salmonella arthritis): Different organism: ensure the correct pathogen-specific code is selected