M87.265
BillableOsteonecrosis due to previous trauma, left fibula
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is M87.265 an HCC code?
Yes. M87.265 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 M87.265
For M87.265 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 M87.265 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
M87.265 is the ICD-10-CM diagnosis code for osteonecrosis due to previous trauma, left fibula. Death of bone tissue in the left smaller bone of the lower leg (fibula) caused by a previous injury or trauma to that area. M87.265 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, M87.265 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, M87.265 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 fibula is specifically documented to differentiate from right fibula (M87.264) or unspecified fibula (M87.266). Because M87.265 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 M87.265 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
Clinical Significance
Left fibular osteonecrosis secondary to trauma affects the lateral support bone of the lower leg, potentially compromising ankle stability and normal gait pattern. This condition requires monitoring for progression and may necessitate orthopedic intervention to prevent further complications.
Documentation Requirements
- ✓Clear identification of left fibula involvement
- ✓Documentation of previous trauma to left lower leg area
- ✓Evidence of bone necrosis in left fibular structures
- ✓Assessment of ankle function and stability
- ✓Current pain assessment and mobility evaluation
- ✓Any concurrent tibial or ankle pathology
- ✓Treatment attempts and patient response
- ✓Impact on gait and weight-bearing activities
Commonly Confused Codes
- •M87.264 — Osteonecrosis due to previous trauma, right fibula (wrong laterality)
- •M87.266 — Osteonecrosis due to previous trauma, unspecified fibula (when laterality is known)
- •M87.262 — Osteonecrosis due to previous trauma, left tibia (different bone)
- •M87.365 — Other secondary osteonecrosis, left fibula (non-traumatic secondary cause)
- •M84.362A — Stress fracture, left fibula (acute injury versus chronic necrosis)