M87.012
BillableIdiopathic aseptic necrosis of left shoulder
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is M87.012 an HCC code?
Yes. M87.012 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 M87.012
For M87.012 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 M87.012 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
M87.012 is the ICD-10-CM diagnosis code for idiopathic aseptic necrosis of left shoulder. Death of bone tissue without infection in the left shoulder joint, occurring without a known cause. M87.012 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, M87.012 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, M87.012 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.
Confirm laterality is documented as 'left' in the medical record. Because M87.012 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 M87.012 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Confirm laterality is documented as 'left' in the medical record
- •This code is specific to the left side; do not use if the side is unspecified or bilateral
Clinical Significance
Idiopathic aseptic necrosis of the left shoulder involves bone death in the humeral head without known cause, typically requiring extensive orthopedic management and potential joint replacement. This condition severely impacts shoulder function and often results in chronic pain and disability affecting work and daily activities.
Documentation Requirements
- ✓Clear documentation of aseptic necrosis involving left shoulder
- ✓Confirmation of idiopathic nature (no identifiable underlying cause)
- ✓Imaging evidence demonstrating bone necrosis in left shoulder structures
- ✓Specific laterality documentation identifying left side involvement
- ✓Exclusion of infectious etiology through clinical assessment
- ✓Range of motion limitations and functional impairment documentation
- ✓Treatment approach including conservative vs surgical management
- ✓Pain assessment and impact on patient's quality of life