M87.236
BillableOsteonecrosis due to previous trauma of unspecified ulna
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is M87.236 an HCC code?
Yes. M87.236 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 M87.236
For M87.236 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 M87.236 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
M87.236 is the ICD-10-CM diagnosis code for osteonecrosis due to previous trauma of unspecified ulna. Death of bone tissue in the forearm bone (ulna) due to previous trauma when the specific side is not identified. M87.236 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, M87.236 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, M87.236 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 only when laterality is not documented or cannot be determined. Because M87.236 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 M87.236 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Use only when laterality is not documented or cannot be determined
- •Query the provider for clarification on which ulna is affected when documentation is ambiguous
Clinical Significance
Post-traumatic osteonecrosis of the ulna represents a serious long-term complication that can significantly impact forearm function and require complex orthopedic management. This condition indicates compromised bone healing and vascular supply following trauma, often necessitating ongoing monitoring and potential surgical intervention.
Documentation Requirements
- ✓Clear identification of ulna bone involvement
- ✓Documentation of previous trauma or injury to the area
- ✓Clinical evidence of bone necrosis (imaging, physical findings)
- ✓Unspecified laterality explicitly stated or bilaterality documented
- ✓Timeline relationship between trauma and osteonecrosis development
- ✓Current functional status and symptoms
- ✓Any related complications or secondary conditions
- ✓Treatment history and response to interventions