What is ICD-10 code T31.64?

T31.64 is the ICD-10-CM diagnosis code for Burns involving 60-69% of body surface with 40-49% third degree burns. Very severe burns affecting 60-69% of the body surface, with 40-49% being third-degree burns that destroy all skin layers. T31.64 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. T31.64 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. T31.64 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. T31.64 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

Which HCC does T31.64 map to under V28?

T31.64 maps to CMS-HCC V28 HCC 385 (Severe Skin Burn or Condition). The category numbers, labels, and conditions come from the CMS-HCC V28 model file for payment year 2026.

2026 ICD-10-CM T31.64: Burns involving 60-69%

T31.64 maps to CMS-HCC V28 385. A source-labeled RAF reference is available. Confirm the documented diagnosis and applicable coding requirements. MEAT criteria · RAF Calculator · HCC Buddy coding tools

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Code lookupT31.64

Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Injury, poisoning and certain other consequences of external causes (S00-T88) / Burns and corrosions of multiple and unspecified body regions (T30-T32)

T31.64

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Burns involving 60-69% of body surface with 40-49% third degree burns

Very severe burns affecting 60-69% of the body surface, with 40-49% being third-degree burns that destroy all skin layers.

Buddy Insight

This represents a life-threatening burn injury with massive body surface involvement and nearly half being full-thickness burns.

Overview Risk Models Code Book Documentation Audit Notes Edition comparison

CMS-HCC V28

Mapped

HCC 385

Severe Skin Burn or Condition

Code-level coefficient reference

CMS-HCC V24

Historical

Not used for standard CY2026 Medicare Advantage payment. Select a historical period to review V24.

Not used for CY2026 payment

ACA/HHS

Mapped

HCC 218

HHS-HCC 218 adult, RAF varies...

Code-level coefficient reference

ESRD/PACE

Mapped

HCC 162

Severe Skin Burn or Condition

Code-level coefficient reference

RXHCC

N/A

—

Not risk-adjusted for this model/period.

Not mapped

Code Book Path

Official

T31Burns classified according to extent of body surface involved T31.6Burns involving 60-69% of body surface T31.64Burns involving 60-69% of body surface with 40-49% third degree burns

Inclusion Terms

Official

No inclusion terms are included in this display for T31.64. Check the code and parent instructions in the Code Book.

Excludes 2

Official

birth trauma (P10-P15)Inherited from S00-T88
obstetric trauma (O70-O71)Inherited from S00-T88

Related Codes

Official

T31.60Burns involving 60-69% of body surface with 0% to 9% third degree burns T31.61Burns involving 60-69% of body surface with 10-19% third degree burns T31.62Burns involving 60-69% of body surface with 20-29% third degree burns T31.63Burns involving 60-69% of body surface with 30-39% third degree burns T31.65Burns involving 60-69% of body surface with 50-59% third degree burns

Includes

Official

No Includes notes are included in this display for T31.64. Check the code and parent instructions in the Code Book.

Excludes 1

Official

No Excludes 1 notes are included in this display for T31.64. Check the code and parent instructions in the Code Book.

Code First

Official

No Code First sequencing instructions are included in this display for T31.64. Check the code and parent instructions in the Code Book.

Use Additional

Official

code to identify any retained foreign body, if applicable (Z18.-)Inherited from S00-T88

Code Also

Official

No Code Also instructions are included in this display for T31.64. Check the code and parent instructions in the Code Book.

Buddy Documentation Tip

HCC Buddy guidance

Total body surface area (TBSA) calculated as 60-69%

Third-degree burns comprising 40-49% of body surface

Standardized burn assessment chart utilized

Complete anatomical burn mapping

MEAT Support

HCC Buddy guidance

Total body surface area (TBSA) calculated as 60-69%

Third-degree burns comprising 40-49% of body surface

Standardized burn assessment chart utilized

Complete anatomical burn mapping

Audit Caution

HCC Buddy guidance

Miscalculating proportion of full-thickness burns

Confusing total surface area with third-degree percentages

Using inappropriate burn assessment tools

Incorrectly classifying burn mechanism

Common Mistakes

HCC Buddy guidance

T31.63 — 30-39% third-degree versus 40-49% third-degree

T31.65 — 50-59% third-degree versus 40-49% third-degree

T31.54 — Total TBSA 50-59% versus 60-69%

T32.64 — Chemical corrosion versus thermal burn

Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →

Is T31.64 an HCC code?

Yes. T31.64 (Burns involving 60-69% of body surface with 40-49% third degree burns) maps to HCC 385, Severe Skin Burn or Condition under the CMS-HCC V28 risk adjustment model, with a source-labeled community non-dual aged reference coefficient of 1.291. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes. It is billable for payment year 2026.

Coder answer: T31.64 is billable and maps to V28 HCC 385, Severe Skin Burn or Condition. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code: T31.64
Description: Burns involving 60-69% of body surface with 40-49% third degree burns
HCC (V28): HCC 385 — Severe Skin Burn or Condition
RAF reference coefficient: 1.291
Billable: Yes
Payment year: 2026

HCC Category Mapping

V28HCC 385, Severe Skin Burn or Condition

1.291

ESRDHCC 162, Severe Skin Burn or Condition

Not separately weighted

These are source-labeled model coefficients, not member totals. A category may still be removed by hierarchy or model cleanup rules. Weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member context, hierarchy and cleanup rules, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains available for historical review.

Work T31.64 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT review for T31.64

For T31.64, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule.

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

Coder workflow notes

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What This Code Means

T31.64 is the ICD-10-CM diagnosis code for burns involving 60-69% of body surface with 40-49% third degree burns. Very severe burns affecting 60-69% of the body surface, with 40-49% being third-degree burns that destroy all skin layers. T31.64 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, T31.64 maps to Severe Skin Burn or Condition (HCC 385) with a source-labeled community, non-dual, aged reference coefficient of 1.291. No V24 mapping is shown for T31.64; use the applicable model and payment year when reviewing the V28 mapping. For CY2026 non-PACE Medicare Advantage, CMS uses 100% of the 2024 CMS-HCC model (V28). PACE uses a separate model blend. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes.

These extensive burns have extremely high mortality rates and require specialized burn unit management. For T31.64, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule. 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, source-labeled coefficient references, and MEAT documentation criteria for T31.64 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•These extensive burns have extremely high mortality rates and require specialized burn unit management
•Ensure all associated injuries and complications are documented and coded separately

Clinical Significance

This represents a life-threatening burn injury with massive body surface involvement and nearly half being full-thickness burns. These patients require immediate burn center management with intensive multidisciplinary care and have extremely high morbidity risk.