M90.552
BillableOsteonecrosis in diseases classified elsewhere, left thigh
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is M90.552 an HCC code?
Yes. M90.552 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 M90.552
For M90.552 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 M90.552 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
M90.552 is the ICD-10-CM diagnosis code for osteonecrosis in diseases classified elsewhere, left thigh. Death of bone tissue in the left thigh bone caused by another disease or condition affecting the body. M90.552 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, M90.552 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, M90.552 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.
Document whether the femoral head, neck, or shaft is affected for complete clinical documentation. Because M90.552 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 M90.552 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Document whether the femoral head, neck, or shaft is affected for complete clinical documentation
- •This manifestation code must be accompanied by the code for the underlying disease causing it
Clinical Significance
This diagnosis represents secondary osteonecrosis affecting the left thigh bone (femur), indicating significant bone death caused by an underlying classified disease. The condition requires intensive medical management and has major risk adjustment implications due to mobility concerns and fracture risk.
Documentation Requirements
- ✓Clear documentation of underlying disease causing secondary osteonecrosis
- ✓Specific identification of left thigh/femur as the affected anatomical location
- ✓Radiological confirmation of osteonecrotic changes (MRI, bone scan, CT)
- ✓Provider statement establishing causal relationship to classified disease
- ✓Comprehensive treatment plan for both primary and secondary conditions
- ✓Mobility assessment and weight-bearing status evaluation
- ✓Documentation excluding primary or traumatic causes of bone necrosis
- ✓Monitoring plan for potential complications including pathological fracture