M87.039
BillableIdiopathic aseptic necrosis of unspecified carpus
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is M87.039 an HCC code?
Yes. M87.039 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 M87.039
For M87.039 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 M87.039 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
M87.039 is the ICD-10-CM diagnosis code for idiopathic aseptic necrosis of unspecified carpus. Death of bone tissue in the wrist bones (carpus) without infection when the side is not specified or documented. M87.039 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, M87.039 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, M87.039 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.
Use only when laterality is truly unknown or not documented in the record. Because M87.039 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 M87.039 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Use only when laterality is truly unknown or not documented in the record
- •Attempt to clarify with the provider or review imaging to determine right versus left involvement
Clinical Significance
Idiopathic aseptic necrosis of unspecified carpus represents bone death in wrist bones when laterality is not documented, indicating a serious condition that can severely impact hand function. This diagnosis often involves the scaphoid or lunate bones and requires orthopedic management to prevent wrist collapse and preserve hand function.
Documentation Requirements
- ✓Documentation of aseptic necrosis affecting carpal bones
- ✓Confirmation of idiopathic etiology without identifiable cause
- ✓Imaging studies demonstrating bone necrosis in carpal structures
- ✓Absence of laterality specification in medical documentation
- ✓Exclusion of infectious causes through clinical assessment
- ✓Wrist functional assessment including range of motion and grip strength
- ✓Treatment plan documentation including therapeutic interventions
- ✓Pain management strategies and functional impact on hand activities