M86.311
BillableChronic multifocal osteomyelitis, right shoulder
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is M86.311 an HCC code?
Yes. M86.311 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 M86.311
For M86.311 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 M86.311 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
M86.311 is the ICD-10-CM diagnosis code for chronic multifocal osteomyelitis, right shoulder. A long-standing bone infection affecting multiple bones, specifically involving the right shoulder. M86.311 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, M86.311 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, M86.311 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 indicates the right shoulder is one of multiple affected sites; document all other involved locations separately. Because M86.311 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 M86.311 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This code indicates the right shoulder is one of multiple affected sites; document all other involved locations separately.
- •Verify laterality is clearly documented as 'right' before assigning this code.
Clinical Significance
Chronic multifocal osteomyelitis represents a severe, persistent bone infection that significantly impacts patient mobility, quality of life, and requires extensive long-term management including antibiotics, surgical interventions, and monitoring for complications. This condition indicates substantial morbidity and healthcare resource utilization due to its chronic nature and multifocal involvement.
Documentation Requirements
- ✓Specific documentation of 'chronic' duration of osteomyelitis
- ✓Clear identification of 'multifocal' nature of the infection
- ✓Anatomic specification of right shoulder involvement
- ✓Evidence of ongoing infection (laboratory values, imaging findings)
- ✓Documentation of causative organism if identified
- ✓Treatment history including antibiotic therapy
- ✓Surgical interventions or procedures performed
- ✓Functional impact and complications noted
Commonly Confused Codes
- •M86.10 — Acute osteomyelitis, unspecified site (lacks chronicity and anatomic specificity)
- •M86.611 — Other chronic osteomyelitis, right shoulder (not multifocal)
- •M25.511 — Pain in right shoulder (symptom only, not infection)
- •M86.411 — Chronic osteomyelitis with draining sinus, right shoulder (has draining sinus component)