M87.038
BillableIdiopathic aseptic necrosis of left carpus
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is M87.038 an HCC code?
Yes. M87.038 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 M87.038
For M87.038 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 M87.038 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
M87.038 is the ICD-10-CM diagnosis code for idiopathic aseptic necrosis of left carpus. Death of bone tissue in the left wrist bones (carpus) without infection, occurring without a known cause. M87.038 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, M87.038 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, M87.038 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 left side is documented and that the condition affects the carpus rather than other hand structures. Because M87.038 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 M87.038 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Verify left side is documented and that the condition affects the carpus rather than other hand structures
- •Review imaging reports to confirm the anatomical location of necrosis
Clinical Significance
Idiopathic aseptic necrosis of the left carpus involves bone death in the wrist bones without known cause, potentially severely compromising hand function and requiring specialized orthopedic intervention. This condition commonly affects weight-bearing carpal bones and can progress to wrist collapse without appropriate treatment.
Documentation Requirements
- ✓Clear documentation of aseptic necrosis involving left carpal bones
- ✓Confirmation of idiopathic nature without identifiable underlying cause
- ✓Radiological evidence showing bone necrosis in left carpal structures
- ✓Specific laterality documentation indicating left wrist involvement
- ✓Clinical exclusion of infectious etiology
- ✓Functional assessment of left wrist mobility and grip strength
- ✓Treatment approach including conservative or surgical management
- ✓Pain documentation and impact on hand function and daily activities