M87.20
BillableOsteonecrosis due to previous trauma, unspecified bone
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is M87.20 an HCC code?
Yes. M87.20 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 M87.20
For M87.20 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 M87.20 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
M87.20 is the ICD-10-CM diagnosis code for osteonecrosis due to previous trauma, unspecified bone. Bone death resulting from a previous injury, with the specific bone not identified. M87.20 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, M87.20 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, M87.20 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.
Identify and document the specific bone affected to use a more specific code (M87.21-M87.29). Because M87.20 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 M87.20 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
Clinical Significance
Trauma-related osteonecrosis of unspecified bone indicates bone death resulting from previous injury when the specific bone location is not documented, requiring evaluation for functional impact and treatment needs. This condition represents a serious complication of trauma that may require ongoing orthopedic management and monitoring for progression.
Documentation Requirements
- ✓Clear documentation of trauma-related etiology
- ✓History of previous injury or trauma
- ✓Imaging evidence of bone necrosis
- ✓Timeline relationship between trauma and bone death development
- ✓Clinical findings consistent with osteonecrosis
- ✓Assessment of functional impact
- ✓Evidence that specific bone location was not determined
- ✓Treatment planning documentation
Commonly Confused Codes
- •M87.00 — Idiopathic osteonecrosis of unspecified bone (no trauma cause)
- •M87.10 — Drug-induced osteonecrosis of unspecified bone (medication-related)
- •M87.30 — Other secondary osteonecrosis of unspecified bone (different secondary cause)
- •Specific site trauma-related codes (M87.21x-M87.28x when location known)
- •S72.009 — Unspecified fracture of unspecified femur (acute injury, not necrosis)