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M87.072

Billable

Idiopathic aseptic necrosis of left ankle

Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)

Is M87.072 an HCC code?

Yes. M87.072 maps to Bone/Joint/Muscle/Severe Soft Tissue Infections/Necrosis under the CMS-HCC V28 risk adjustment model (and Bone/Joint/Muscle Infections/Necrosis under V24).

HCC Category Mapping

V28HCC 92Bone/Joint/Muscle/Severe Soft Tissue Infections/Necrosis
0.479
V24HCC 39Bone/Joint/Muscle Infections/Necrosis
0.401
ESRDHCC 39Bone/Joint/Muscle Infections/Necrosis
0.092
RxHCCHCC 80Aseptic Necrosis of Bone
0.204

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 M87.072

For M87.072to 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 M87.072 during that encounter — not just copy-forwarded from a problem list.

What This Code Means

M87.072 is the ICD-10-CM diagnosis code for idiopathic aseptic necrosis of left ankle. Death of bone tissue in the left ankle without infection, occurring without a known cause. M87.072 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, M87.072 maps to Bone/Joint/Muscle/Severe Soft Tissue Infections/Necrosis (HCC 92) with a community, non-dual, aged base RAF weight of 0.479. Under the older CMS-HCC V24 model, M87.072 maps to Bone/Joint/Muscle Infections/Necrosis (HCC 39) with a community, non-dual, aged base RAF weight of 0.401. 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-sided involvement is clearly documented in the clinical notes. Because M87.072 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 M87.072 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

  • Verify left-sided involvement is clearly documented in the clinical notes
  • Consider imaging findings (MRI or CT) that confirm avascular necrosis of the ankle

Clinical Significance

Idiopathic aseptic necrosis of the left ankle indicates bone death without infection in the left ankle joint structures, occurring without identifiable cause. This condition poses significant threat to ankle function and mobility, requiring specialized management to preserve joint integrity and prevent progression to ankle collapse or arthritis.

Documentation Requirements

  • Documentation of aseptic necrosis affecting left ankle
  • Evidence of idiopathic etiology (unknown cause)
  • Imaging confirmation of ankle bone necrosis without infection
  • Assessment of ankle joint stability and function
  • Exclusion of known causes of osteonecrosis
  • Documentation ruling out infectious ankle conditions
  • Treatment approach for joint preservation
  • Functional impact assessment on ambulation

Commonly Confused Codes

  • M87.071 — Idiopathic aseptic necrosis of right ankle affects opposite side
  • M86.672 — Chronic osteomyelitis left ankle/foot involves infection
  • M87.272 — Osteonecrosis due to drugs of left ankle has identifiable cause
  • M25.572 — Pain in left ankle doesn't indicate bone necrosis

Code Hierarchy

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