T31.91
BillableBurns involving 90% or more of body surface with 10-19% third degree burns
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is T31.91 an HCC code?
Yes. T31.91 maps to Severe Skin Burn or Condition under the CMS-HCC V28 risk adjustment model (and Severe Skin Burn or Condition 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 T31.91
For T31.91to 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 T31.91 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
T31.91 is the ICD-10-CM diagnosis code for burns involving 90% or more of body surface with 10-19% third degree burns. Severe burns covering 90% or more of the body with 10-19% being the most serious third-degree burns that destroy all skin layers. T31.91 sits in the ICD-10-CM chapter for injury, poisoning and certain other consequences of external causes (s00-t88), within the section covering burns and corrosions of multiple and unspecified body regions (t30-t32).
Under the CMS-HCC V28 risk adjustment model, T31.91 maps to Severe Skin Burn or Condition (HCC 385) with a community, non-dual, aged base RAF weight of 0.350. Under the older V24 model, T31.91 mapped to the same category but with a base RAF weight of 0.517 — 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 code requires documentation of both total body surface area (90%+) and the specific percentage of third-degree burns (10-19%). Because T31.91 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 T31.91 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This code requires documentation of both total body surface area (90%+) and the specific percentage of third-degree burns (10-19%)
- •Use with additional codes to specify burn location and whether the burn is initial encounter, sequela, or subsequent treatment
Clinical Significance
This code represents the most catastrophic burn injury possible with near-complete body surface involvement and moderate full-thickness component. These patients face maximum mortality risk and require immediate burn center management with all available intensive support.
Documentation Requirements
- ✓Total body surface area (TBSA) documented as 90% or more
- ✓Third-degree burns comprising 10-19% of body surface
- ✓Comprehensive burn assessment using validated methodology
- ✓Complete anatomical burn distribution documentation
- ✓Burn mechanism and etiology clearly specified
- ✓Full burn depth evaluation and classification
- ✓All complications and associated injuries noted
- ✓Maximum burn center protocols and intensive care