M87.88
BillableOther osteonecrosis, other site
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is M87.88 an HCC code?
Yes. M87.88 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 M87.88
For M87.88 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 M87.88 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
M87.88 is the ICD-10-CM diagnosis code for other osteonecrosis, other site. Death of bone tissue in body locations other than those specifically listed in the osteonecrosis classification. This can affect various bones and lead to pain and functional impairment. M87.88 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, M87.88 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, M87.88 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 this code for osteonecrosis in sites not otherwise specified (e.g., pelvis, ribs, sternum). Because M87.88 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 M87.88 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Use this code for osteonecrosis in sites not otherwise specified (e.g., pelvis, ribs, sternum)
- •Document the specific anatomical site affected to support medical necessity and justify treatment decisions
Clinical Significance
Other site osteonecrosis represents avascular bone death occurring in anatomical locations not specifically categorized elsewhere, indicating the systemic nature of the underlying condition. This broad category requires careful documentation of the specific site and underlying etiology.
Documentation Requirements
- ✓Specific anatomical site documentation (not covered by other M87 codes)
- ✓Imaging evidence confirming osteonecrosis at the specified location
- ✓Clear exclusion of traumatic, infectious, or radiation-induced causes
- ✓Assessment of functional impact related to affected site
- ✓Pain evaluation and quality of life measures
- ✓Comprehensive evaluation for underlying systemic conditions
- ✓Multidisciplinary care plan appropriate to anatomical location
- ✓Disease progression monitoring and treatment response