M90.541
BillableOsteonecrosis in diseases classified elsewhere, right hand
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is M90.541 an HCC code?
Yes. M90.541 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 M90.541
For M90.541 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 M90.541 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
M90.541 is the ICD-10-CM diagnosis code for osteonecrosis in diseases classified elsewhere, right hand. Death of bone tissue in the right hand caused by another disease or condition affecting the body. M90.541 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, M90.541 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, M90.541 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.
Hand includes carpal bones, metacarpals, and phalanges; document which specific bones are affected when possible. Because M90.541 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 M90.541 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Hand includes carpal bones, metacarpals, and phalanges; document which specific bones are affected when possible
- •Always code the underlying disease first, then this manifestation code
Clinical Significance
This code represents secondary osteonecrosis specifically affecting the right hand, indicating bone death caused by an underlying classified disease. The condition requires ongoing medical management and significantly impacts risk adjustment modeling due to associated functional limitations and complex care needs.
Documentation Requirements
- ✓Identification of the underlying disease causing secondary osteonecrosis
- ✓Specific documentation of right hand as affected anatomical site
- ✓Radiological evidence of bone necrosis (MRI, bone scan, CT imaging)
- ✓Clinical correlation establishing disease-to-osteonecrosis relationship
- ✓Current treatment modalities and management approach
- ✓Functional assessment and impact on activities of daily living
- ✓Provider statement confirming secondary nature of osteonecrosis
- ✓Documentation excluding traumatic or primary causes