B42.82
BillableSporotrichosis arthritis
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is B42.82 an HCC code?
Yes. B42.82 maps to Bone/Joint/Muscle Infections/Necrosis under the CMS-HCC V28 risk adjustment model (and Bone/Joint/Muscle Infections/Necrosis under V24).
HCC Category Mapping
RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. 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.
MEAT Criteria for B42.82
For B42.82 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 B42.82 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
B42.82 is the ICD-10-CM diagnosis code for sporotrichosis arthritis. A fungal infection of the joints caused by Sporothrix that causes inflammation and joint damage. B42.82 sits in the ICD-10-CM chapter for certain infectious and parasitic diseases (a00-b99), within the section covering mycoses (b35-b49).
Under the CMS-HCC V28 risk adjustment model, B42.82 maps to Bone/Joint/Muscle Infections/Necrosis (HCC 92) with a community, non-dual, aged base RAF weight of 0.209. Under the older V24 model, B42.82 mapped to the same category but with a base RAF weight of 0.482 — V28 recalibrated weights across the entire model. 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.
Document which joints are affected and whether this is monoarticular or polyarticular involvement. Because B42.82 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 B42.82 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Document which joints are affected and whether this is monoarticular or polyarticular involvement
- •Distinguish from other causes of arthritis; sporotrichosis arthritis is relatively rare
Clinical Significance
Sporotrichosis arthritis is a rare fungal joint infection caused by Sporothrix schenckii that causes destructive arthritis requiring prolonged antifungal therapy and potentially surgical intervention. It maps to a musculoskeletal infection HCC rather than a general opportunistic infection HCC, reflecting its distinct clinical impact on bone and joint structures.
Documentation Requirements
- ✓Culture-confirmed Sporothrix schenckii from joint aspirate or synovial tissue
- ✓Specific joint(s) affected documented with laterality
- ✓Imaging findings showing joint destruction, erosions, or synovial thickening
- ✓Occupational or environmental exposure history (gardeners, rose thorn injuries, sphagnum moss)
- ✓Duration of arthritis and treatment plan (itraconazole long-term, amphotericin B for severe cases)