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M72.6

Billable

Necrotizing fasciitis

Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)

Is M72.6 an HCC code?

Yes. M72.6 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

V28HCC 92Bone/Joint/Muscle Infections/Necrosis
0.209
V24HCC 39Bone/Joint/Muscle Infections/Necrosis
0.482
ESRDHCC 39Bone/Joint/Muscle Infections/Necrosis
0.000

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 M72.6

For M72.6 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 M72.6 during that encounter — not just copy-forwarded from a problem list.

What This Code Means

M72.6 is the ICD-10-CM diagnosis code for necrotizing fasciitis. A serious, rapidly spreading bacterial infection of the tissue layers beneath the skin that can cause severe tissue death and requires urgent medical treatment. M72.6 sits in the ICD-10-CM chapter for diseases of the musculoskeletal system and connective tissue (m00-m99), within the section covering other soft tissue disorders (m70-m79).

Under the CMS-HCC V28 risk adjustment model, M72.6 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, M72.6 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.

This is a medical emergency; coordinate coding with sepsis codes if present (R65.2x). Because M72.6 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 M72.6 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

  • This is a medical emergency; coordinate coding with sepsis codes if present (R65.2x)
  • Specify anatomical site and laterality; document causative organism when identified for complete coding

Clinical Significance

Necrotizing fasciitis is a life-threatening soft tissue infection requiring immediate aggressive treatment including surgical debridement and intensive antimicrobial therapy. This diagnosis represents a medical emergency with high mortality risk and significant long-term morbidity potential, requiring intensive monitoring and multidisciplinary care.

Documentation Requirements

  • Clinical diagnosis of necrotizing fasciitis with tissue necrosis
  • Surgical findings or pathological confirmation of fascial involvement
  • Documentation of rapid progression and systemic toxicity
  • Microbiological studies and culture results when available
  • Evidence of tissue destruction and necrosis
  • Treatment with surgical debridement and antibiotics
  • Assessment of extent and depth of infection

Use Additional Code

  • code (B95.-, B96.-) to identify causative organism

Commonly Confused Codes

  • L03.90 — Cellulitis, unspecified (superficial infection without necrosis)
  • T79.3 — Post-traumatic wound infection (infection without tissue death)
  • L08.9 — Local infection of skin and subcutaneous tissue, unspecified
  • A49.9 — Bacterial infection, unspecified (systemic without tissue necrosis)
  • L97.909 — Non-pressure chronic ulcer (chronic wound without acute infection)

Code Hierarchy

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