2026 ICD-10-CM Diagnosis Code T67.01XAHeatstroke and sunstroke, initial encounter

ICD-10-CM Codes›S00–T88›T66-T78›T67

ICD-10-CM T67.01XA
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T67.01XA is a billable ICD-10-CM diagnosis code for heatstroke and sunstroke, initial encounter. The 7th character A marks it as an initial encounter code, used while the patient is receiving active treatment. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 922 through 923. Coders also document this condition as heat exposure. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Effect of other external causes, initial encounter.

Code Identity

ICD-10-CM Code
T67.01XA
Billable Status
Yes — Valid for Submission
Code Describes
Heatstroke and sunstroke, initial encounter
Short Description
Heatstroke and sunstroke, initial encounter
Same as the full description in the CMS dataset.
Parent Code
T67.01
Heatstroke and sunstroke

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionT66-T78Other and unspecified effects of external causes
CategoryT67Effects of heat and light
This CodeT67.01XAHeatstroke and sunstroke, initial encounter

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Heat exposure
  • Heat stroke
  • Hyperthermia
  • Sunstroke

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Effects of heat and light (T67). Use the following options for the applicable episode of care:

  • A - initial encounter
  • D - subsequent encounter
  • S - sequela

Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2026, published by CMS and the National Center for Health Statistics.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INJ021
Effect of other external causes, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Drug Fever

    drug-induced fever.

  • Hyperthermia

    an abnormal elevation of body temperature, usually as a result of inability to regulate core body temperature due to non-pathologic factors.

  • Hyperthermia, Induced

    abnormally high temperature intentionally induced in living things regionally or whole body. it is most often induced by radiation (heat waves, infra-red), ultrasound, or drugs.

  • Malignant Hyperthermia

    rapid and excessive rise of temperature accompanied by muscular rigidity following general anesthesia.

  • Sunstroke

    heat stroke caused by exposure to the sun. it is characterized by dangerously high body temperature; red, hot skin; delusions; convulsions; or coma. it can be a life-threatening emergency and is most common in infants and the elderly.

  • Heat Stroke

    a condition caused by the failure of body to dissipate heat in an excessively hot environment or during physical exertion in a hot environment. contrast to heat exhaustion, the body temperature in heat stroke patient is dangerously high with red, hot skin accompanied by delusions; convulsions; or coma. it can be a life-threatening emergency and is most common in infants and the elderly.

Patient EducationClinical

Heat Illness

Your body normally cools itself by sweating. During hot weather, especially when it is very humid, sweating just isn't enough to cool you off. Your body temperature can rise to dangerous levels and you can develop a heat illness.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Code History & ChangesHistory

Replacement T67.01XA replaces the following previously assigned code(s):

  • T67.0XXA - Heatstroke and sunstroke, initial encounter
FY 2020AddedAdded to the ICD-10-CM code setEffective October 1, 2019.
FY 2021–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About T67.01XAOverview

Is T67.01XA (Heatstroke and sunstroke) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report heatstroke and sunstroke, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in T67.01XA mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for heatstroke and sunstroke, such as an emergency visit or first evaluation.

What MS-DRG does T67.01XA group to?

When heatstroke and sunstroke, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 922, 923, with relative weights from 1.0177 to 1.7494 depending on complications. Higher weights mean higher Medicare reimbursement.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.