M87.831
BillableOther osteonecrosis of right radius
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is M87.831 an HCC code?
Yes. M87.831 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 M87.831
For M87.831 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 M87.831 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
M87.831 is the ICD-10-CM diagnosis code for other osteonecrosis of right radius. Death of bone tissue in the right radius (larger forearm bone) due to causes other than trauma or infection, leading to bone deterioration and potential collapse. M87.831 sits in the ICD-10-CM chapter for diseases of the musculoskeletal system and connective tissue (m00-m99), within the section covering other osteopathies (m86-m90).
Under the CMS-HCC V28 risk adjustment model, M87.831 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, M87.831 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.
Verify laterality is documented as right; if not specified, use M87.833 for unspecified side. Because M87.831 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 M87.831 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Verify laterality is documented as right; if not specified, use M87.833 for unspecified side
- •Investigate and document the underlying cause (idiopathic, radiation, corticosteroid use, etc.) as this may affect treatment decisions
Clinical Significance
Osteonecrosis of the right radius represents a chronic condition affecting the primary weight-bearing bone of the forearm, potentially leading to wrist dysfunction and disability. This diagnosis is clinically significant for risk adjustment as it indicates ongoing orthopedic management needs and potential complications requiring specialized care.
Documentation Requirements
- ✓Specific identification of the right radius as the affected bone
- ✓Documentation of osteonecrosis from causes other than trauma or infection
- ✓Imaging confirmation (MRI, X-ray, bone scan) showing bone necrosis
- ✓Clinical symptoms such as wrist pain, stiffness, or limited range of motion
- ✓Evidence ruling out idiopathic or drug-induced causes
- ✓Assessment of functional impact on wrist and hand mobility
- ✓Documentation of any underlying risk factors or contributing conditions
- ✓Provider evaluation of disease progression and treatment response