2027 ICD-10-CM Diagnosis Code T67.3XXAHeat exhaustion, anhydrotic, initial encounter
T67.3XXA is a billable ICD-10-CM diagnosis code for heat exhaustion, anhydrotic, 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 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 922 through 923. Coders also document this condition as anhidrosis. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Effect of other external causes, initial encounter.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Anhidrosis
- Heat exhaustion
- Heat exhaustion co-occurrent and due to anhidrosis
- Heat-induced dermatosis
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 2027, published by CMS and the National Center for Health Statistics.
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to T67.3XXA: its own notes plus those printed at T67.3, T67, block T66-T78, and Chapter 19. A note printed at a category, block or chapter applies to every code under it.
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
- heat exhaustion due to salt depletion (T67.4)
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.
Use Additional Code
Add a second code, after this one, to fully describe the condition.
- code to identify any retained foreign body, if applicable (Z18.-)
Code Also
A second code may be needed to fully describe the condition; the note gives no sequencing direction.
- if applicable, place of occurrence, such as:
- highway rest stop (Y92.523)
- school (private) (public) (state) as the place of occurrence of the external cause (Y92.21-)
- service areas as the place of occurrence of the external cause (Y92.52-)
- single-family non-institutional (private) house as the place of occurrence of the external cause (Y92.01-)
- transport vehicle as the place of occurrence of the external cause (Y92.81-)
Notes
General instructions on how these codes are used.
- Use secondary code(s) from Chapter 20, External causes of morbidity, to indicate cause of injury. Codes within the T section that include the external cause do not require an additional external cause code
- The chapter uses the S-section for coding different types of injuries related to single body regions and the T-section to cover injuries to unspecified body regions as well as poisoning and certain other consequences of external causes.
7th Character
Every code in the category takes a 7th character from the listed values, with the placeholder X filling any empty positions before it.
- The appropriate 7th character is to be added to each code from category T67
- Ainitial encounter this code
- Dsubsequent encounter
- Ssequela
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name T67.3XXA, its category, or a range that includes it.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Heat Exhaustion
a clinical syndrome caused by heat stress, such as over-exertion in a hot environment or excessive exposure to sun. it is characterized by sweating, water (volume) depletion, salt depletion, cool clammy skin, nausea, and headache.
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.
Convert T67.3XXA to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About T67.3XXAOverview
What is the ICD-10 code for heat exhaustion, anhydrotic, initial encounter?
The ICD-10-CM code for heat exhaustion, anhydrotic, initial encounter is T67.3XXA (sometimes written as T673XXA). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is T67.3XXA (Heat exhaustion, anhydrotic) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report heat exhaustion, anhydrotic, initial encounter on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What does the 7th character A in T67.3XXA mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for heat exhaustion, anhydrotic, such as an emergency visit or first evaluation.
What MS-DRG does T67.3XXA group to?
When heat exhaustion, anhydrotic, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 923, 922, with relative weights from 0.9980 to 1.6248 depending on complications. Higher weights mean higher Medicare reimbursement.
Can T67.3XXA be reported with T67.4?
Not as a rule. The Excludes1 note at T67.3, which applies to T67.3XXA, lists "heat exhaustion due to salt depletion (T67.4)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
