L97.904
BillableNon-pressure chronic ulcer of unspecified part of unspecified lower leg with necrosis of bone
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is L97.904 an HCC code?
Yes. L97.904 maps to Chronic Ulcer of Skin, Except Pressure under the CMS-HCC V28 risk adjustment model (and Chronic Ulcer of Skin, Except Pressure 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 L97.904
For L97.904to 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 L97.904 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
L97.904 is the ICD-10-CM diagnosis code for non-pressure chronic ulcer of unspecified part of unspecified lower leg with necrosis of bone. A long-lasting open sore on an unspecified part of an unspecified lower leg (not from pressure) where the bone is dead. L97.904 sits in the ICD-10-CM chapter for diseases of the skin and subcutaneous tissue (l00-l99), within the section covering other disorders of the skin and subcutaneous tissue (l80-l99).
Under the CMS-HCC V28 risk adjustment model, L97.904 maps to Chronic Ulcer of Skin, Except Pressure (HCC 380) with a community, non-dual, aged base RAF weight of 0.426. The V24 model used during the PY2024–PY2025 transition mapped L97.904 the same way and at the same RAF weight. 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 represents the most severe ulcer stage with bone necrosis; ensure clinical documentation supports bone involvement and necrosis. Because L97.904 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 L97.904 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This represents the most severe ulcer stage with bone necrosis; ensure clinical documentation supports bone involvement and necrosis
- •Specify the leg and location when possible to use a more specific code rather than the unspecified version
Clinical Significance
This non-pressure chronic ulcer on the unspecified part of unspecified lower leg with bone necrosis represents the most severe form of chronic ulceration, with osteonecrosis indicating potential osteomyelitis and high risk for amputation. Chronic non-pressure ulcers are significant for risk adjustment because they indicate ongoing complex wound management needs, increased healthcare utilization, and often reflect underlying systemic conditions such as peripheral vascular disease, diabetes mellitus, or venous insufficiency. Accurate severity coding directly impacts care planning, specialist referral decisions, and appropriate resource allocation for wound care services.
Documentation Requirements
- ✓Confirmation that the ulcer is chronic (present for extended duration, not acute)
- ✓Documentation that the ulcer is NOT caused by pressure (non-pressure etiology)
- ✓Specific anatomical site of the ulcer on the unspecified part of unspecified lower leg
- ✓Query provider for laterality if not documented (left vs. right)
- ✓Clinical documentation of bone necrosis (osteonecrosis/osteomyelitis)
- ✓Imaging studies (X-ray, MRI, or bone scan) supporting bone involvement
- ✓Description of necrotic bone tissue characteristics
- ✓Underlying etiology or contributing conditions (e.g., venous insufficiency, arterial disease, diabetes mellitus, neuropathy)
- ✓Current wound measurements (length, width, depth) and wound bed description
- ✓Current treatment plan and wound care management
Commonly Confused Codes
- •L97.906 — bone involvement WITHOUT necrosis — critical distinction: necrosis means tissue death
- •L97.903 — muscle necrosis — less severe, verify bone vs. muscle involvement
- •L89.xxx — Pressure ulcer codes; L97 is specifically for NON-pressure chronic ulcers
- •L97.5xx — Foot ulcer codes; verify whether the ulcer is on the leg or foot