M87.345
BillableOther secondary osteonecrosis, left finger(s)
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is M87.345 an HCC code?
Yes. M87.345 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 M87.345
For M87.345 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 M87.345 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
M87.345 is the ICD-10-CM diagnosis code for other secondary osteonecrosis, left finger(s). Death of bone tissue in the left finger(s) caused by an underlying condition or treatment, resulting in bone deterioration and potential loss of function. M87.345 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, M87.345 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, M87.345 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.
Verify laterality is documented as left in the medical record before assigning this code. Because M87.345 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 M87.345 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Verify laterality is documented as left in the medical record before assigning this code
- •Investigate the underlying cause (such as trauma, radiation, or corticosteroid use) and code it as a secondary diagnosis
Clinical Significance
This diagnosis represents secondary osteonecrosis of the left finger bones caused by underlying conditions such as corticosteroid therapy, radiation exposure, or systemic diseases. It requires ongoing monitoring for bone collapse and potential surgical intervention, while identifying and managing the causative factor.
Documentation Requirements
- ✓Documentation of osteonecrosis affecting left finger(s)
- ✓Identification of underlying cause (e.g., corticosteroid use, radiation, sickle cell disease)
- ✓Imaging findings confirming bone necrosis (MRI, X-ray, CT)
- ✓Clinical symptoms such as pain, stiffness, or functional impairment
- ✓Specific finger(s) affected if known
- ✓Duration and progression of condition
- ✓Treatment history and response
- ✓Functional impact on hand use
Commonly Confused Codes
- •M87.845 — Other osteonecrosis of left finger(s) (other causes vs secondary)
- •M87.344 — Other secondary osteonecrosis, right finger(s) (different laterality)
- •M87.346 — Other secondary osteonecrosis, unspecified finger(s) (laterality not specified)
- •M86.15 — Osteomyelitis of left finger (infection vs necrosis)
- •S62.90XA — Fracture of left finger (acute injury vs chronic necrosis)