M86.612
BillableOther chronic osteomyelitis, left shoulder
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is M86.612 an HCC code?
Yes. M86.612 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 M86.612
For M86.612 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 M86.612 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
M86.612 is the ICD-10-CM diagnosis code for other chronic osteomyelitis, left shoulder. A long-term bone infection in the left shoulder area. M86.612 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, M86.612 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, M86.612 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.
Ensure left shoulder is clearly documented to differentiate from right-sided infection. Because M86.612 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 M86.612 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Ensure left shoulder is clearly documented to differentiate from right-sided infection
- •Verify this is chronic osteomyelitis rather than acute infection
Clinical Significance
Chronic osteomyelitis of the left shoulder represents a persistent bone infection that severely compromises upper extremity function and quality of life. This condition often requires prolonged antibiotic therapy and may necessitate surgical intervention, significantly impacting the patient's ability to perform work and daily activities.
Documentation Requirements
- ✓Confirmation of chronic nature (minimum 6 weeks duration or recurrent)
- ✓Specific documentation of left shoulder bone involvement
- ✓Non-hematogenous etiology (contiguous spread or direct inoculation)
- ✓Radiographic evidence of bone infection or osteomyelitic changes
- ✓Laboratory studies supporting chronic infection process
- ✓Functional assessment of left shoulder and upper extremity
- ✓Documentation of antibiotic therapy and surgical procedures
- ✓Assessment of occupational and functional limitations
Commonly Confused Codes
- •M86.512 — Other chronic hematogenous osteomyelitis, left shoulder (hematogenous origin)
- •M86.611 — Other chronic osteomyelitis, right shoulder (opposite side)
- •M86.412 — Chronic osteomyelitis with draining sinus, left shoulder (has sinus tract)
- •M86.112 — Other acute osteomyelitis, left shoulder (acute presentation)
- •M75.32 — Calcific tendinitis of left shoulder (soft tissue condition)