M86.512
BillableOther chronic hematogenous osteomyelitis, left shoulder
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is M86.512 an HCC code?
Yes. M86.512 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 M86.512
For M86.512to 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 M86.512 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
M86.512 is the ICD-10-CM diagnosis code for other chronic hematogenous osteomyelitis, left shoulder. A chronic bone infection of the left shoulder that developed from a bloodstream infection. M86.512 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, M86.512 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, M86.512 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.
Ensure documentation clearly specifies left shoulder to justify this laterality-specific code. Because M86.512 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 M86.512 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Ensure documentation clearly specifies left shoulder to justify this laterality-specific code
- •If the shoulder bone location is documented, consider whether a more specific code under the shoulder category applies
Clinical Significance
Other chronic hematogenous osteomyelitis of the left shoulder represents a blood-borne bone infection that has progressed to chronic status, specifically involving the left shoulder girdle. This condition indicates systemic infection with targeted bone involvement requiring intensive antibiotic therapy and ongoing monitoring, substantially affecting upper extremity mobility and functional capacity.
Documentation Requirements
- ✓Documentation of chronic osteomyelitis diagnosis
- ✓Evidence of hematogenous origin through blood-borne spread
- ✓Anatomic specification of left shoulder involvement
- ✓Laboratory studies demonstrating systemic infection
- ✓Blood culture results or evidence of bacteremia
- ✓Confirmation of chronic duration and treatment history
- ✓Imaging studies confirming left shoulder bone infection
- ✓Functional assessment and impact on daily activities
Commonly Confused Codes
- •M86.511 — Other chronic hematogenous osteomyelitis, right shoulder (incorrect laterality)
- •M86.612 — Other chronic osteomyelitis, left shoulder (not specifically hematogenous)
- •M86.312 — Chronic multifocal osteomyelitis, left shoulder (multifocal rather than hematogenous)
- •M86.412 — Chronic osteomyelitis with draining sinus, left shoulder (has draining sinus component)