M86.372
BillableChronic multifocal osteomyelitis, left ankle and foot
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is M86.372 an HCC code?
Yes. M86.372 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 M86.372
For M86.372 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 M86.372 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
M86.372 is the ICD-10-CM diagnosis code for chronic multifocal osteomyelitis, left ankle and foot. A chronic bone infection affecting multiple areas of the left ankle and foot bones, characterized by long-standing inflammation and possible drainage. M86.372 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, M86.372 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, M86.372 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.
Confirm laterality is documented as 'left' in the clinical notes. Because M86.372 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 M86.372 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Confirm laterality is documented as 'left' in the clinical notes
- •Document which specific bones of the ankle and foot are involved when possible
Clinical Significance
This diagnosis represents chronic multifocal osteomyelitis of the left ankle and foot, a severe condition affecting weight-bearing bones with significant functional implications. The complex anatomy of the foot increases treatment difficulty and risk for long-term complications including chronic pain and disability.
Documentation Requirements
- ✓Clear documentation of left ankle and foot involvement
- ✓Evidence supporting chronic nature (duration >6 weeks or recurrent)
- ✓Confirmation of multifocal involvement in ankle/foot structures
- ✓Radiographic studies showing chronic osteomyelitic changes
- ✓Functional assessment of left foot and ankle
- ✓Laboratory markers consistent with chronic infection
- ✓Treatment history including surgical and medical interventions
- ✓Clinical confirmation of chronic multifocal osteomyelitis diagnosis