A48.0 ICD-10-CM Code: Gas gangrene
HCC Buddy Code Card
Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.
FY 2026 Apr update / Certain infectious and parasitic diseases (A00-B99) / Other bacterial diseases (A30-A49)
A48.0
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceGas gangrene
Gas gangrene is a serious and rapidly spreading infection of muscle tissue caused by bacteria that produce gas bubbles in the affected area, typically occurring after an injury or surgical wound. This is a life-threatening condition that requires immediate medical attention and often emergency surgery.
Buddy Insight
Gas gangrene (clostridial myonecrosis) is a rapidly progressive, life-threatening necrotizing soft tissue infection caused by Clostridium perfringens and other gas-producing Clostridium species.
CMS-HCC V28
MappedHCC 263
RAF 0.742
CMS-HCC V24
MappedHCC 106
RAF 0.860
ACA/HHS
00
RAF 0
ESRD/PACE
MappedHCC 106
RAF 0.0
RXHCC
00
RAF 0
Code Trumping
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Code Book Path
Inclusion Terms
Official- Clostridial cellulitis
- Clostridial myonecrosis
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for A48.0 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for A48.0 in this effective period.
Excludes 1
Official- actinomycetoma (B47.1)
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for A48.0 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for A48.0 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for A48.0 in this effective period.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.
Is A48.0 an HCC code?
Yes. A48.0 maps to Atherosclerosis of the Extremities with Ulceration or Gangrene under the CMS-HCC V28 risk adjustment model (and Atherosclerosis of the Extremities with Ulceration or Gangrene 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 A48.0
For A48.0to 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 A48.0 during that encounter, not just copy-forwarded from a problem list.
What This Code Means
A48.0 is the ICD-10-CM diagnosis code for gas gangrene. Gas gangrene is a serious and rapidly spreading infection of muscle tissue caused by bacteria that produce gas bubbles in the affected area, typically occurring after an injury or surgical wound. This is a life-threatening condition that requires immediate medical attention and often emergency surgery. A48.0 sits in the ICD-10-CM chapter for certain infectious and parasitic diseases (a00-b99), within the section covering other bacterial diseases (a30-a49).
Under the CMS-HCC V28 risk adjustment model, A48.0 maps to Atherosclerosis of the Extremities with Ulceration or Gangrene (HCC 263) with a community, non-dual, aged base RAF weight of 0.742. Under the older V24 model, A48.0 mapped to the same category but with a base RAF weight of 0.860, 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.
Gas gangrene is caused by Clostridium perfringens and other gas-producing bacteria; document the causative organism if identified, as this may affect treatment decisions. Because A48.0 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 A48.0 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Gas gangrene is caused by Clostridium perfringens and other gas-producing bacteria; document the causative organism if identified, as this may affect treatment decisions
- •This code should be paired with codes indicating the site of infection (such as a wound code) and any associated complications; consider whether this is a primary diagnosis or secondary to trauma
Clinical Significance
Gas gangrene (clostridial myonecrosis) is a rapidly progressive, life-threatening necrotizing soft tissue infection caused by Clostridium perfringens and other gas-producing Clostridium species. It destroys muscle tissue with remarkable speed and produces gas within tissues. Without emergent surgical debridement and high-dose penicillin with clindamycin, mortality approaches 100%.
Documentation Requirements
- ✓Clinical findings of crepitus (gas in tissues), rapidly spreading necrosis, and severe pain disproportionate to examination
- ✓Imaging showing gas in soft tissues (X-ray or CT demonstrating subcutaneous/intramuscular gas)
- ✓Surgical findings documenting devitalized muscle tissue and gas formation
- ✓Wound culture or tissue culture identifying Clostridium species
- ✓Rapid surgical debridement or amputation documented with timing
Commonly Confused Codes
- •M72.6 (Necrotizing fasciitis) — Necrotizing fasciitis affects fascia; gas gangrene (A48.0) specifically involves muscle with gas production. They can coexist
- •L03.90 (Cellulitis, unspecified) — Cellulitis is superficial skin infection; gas gangrene is deep muscle necrosis — vastly different severity
- •A41.4 (Sepsis due to anaerobes) — Code A41.4 separately when gas gangrene progresses to sepsis; A48.0 alone does not capture the sepsis