M90.512
BillableOsteonecrosis in diseases classified elsewhere, left shoulder
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is M90.512 an HCC code?
Yes. M90.512 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 M90.512
For M90.512 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 M90.512 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
M90.512 is the ICD-10-CM diagnosis code for osteonecrosis in diseases classified elsewhere, left shoulder. Death of bone tissue in the left shoulder caused by another disease. M90.512 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, M90.512 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, M90.512 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.
This code requires documentation of the underlying etiology; code the primary disease separately. Because M90.512 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 M90.512 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This code requires documentation of the underlying etiology; code the primary disease separately
- •Confirm left shoulder is the affected side; do not assume laterality without explicit documentation
Clinical Significance
Secondary osteonecrosis of the left shoulder represents bone death in a major upper extremity joint caused by underlying disease, significantly impacting patient function and quality of life. This condition requires comprehensive management addressing both the causative disease and skeletal complications.
Documentation Requirements
- ✓Primary disease causing osteonecrosis clearly documented and coded first
- ✓Left shoulder specifically identified as the affected anatomical site
- ✓Clinical evidence supporting diagnosis of bone tissue death
- ✓Diagnostic imaging confirming presence of osteonecrosis
- ✓Assessment of shoulder function and range of motion
- ✓Comprehensive treatment plan addressing underlying disease and bone necrosis
- ✓Documentation of disease progression or staging