X30 Exposure to excessive natural heat

The ICD-10-CM code for Exposure to excessive natural heat is X30 (FY2026). It is a billable, claim-ready diagnosis code.

Classification

Chapter

20: External causes of morbidity (V00-Y99)

Section

X30-X39: Exposure to forces of nature (X30-X39)

Category X30

1 code (1 billable)

FY2026 Status

Stable since FY2024

Inclusion Terms

• Exposure to excessive heat as the cause of sunstroke
• Exposure to heat NOS

Official Coding Guidelines

Other external cause issues—when not direct hurricane result

c. Other External Causes of Morbidity Code Issues For injuries that are not a direct result of the hurricane, such as an evacuee that has incurred an injury as a result of a motor vehicle accident, assign the appropriate external cause of morbidity code(s) to describe the cause of the injury, but do not assign code X37.0-, Hurricane. If it is not clear whether the injury was a direct result of the hurricane, assume the injury is due to the hurricane and assign code X37.0-, Hurricane, as well as any other applicable external cause of morbidity codes. In addition to code X37.0-, Hurricane, other possible applicable external cause of morbidity codes include: X30-, Exposure to excessive natural heat X31-, Exposure to excessive natural cold X38-, Flood

Used with any code in range A00.0-T88.9, Z00-Z99

1) Used with any code in the range of A00.0-T88.9, Z00-Z99 An external cause code may be used with any code in the range of A00.0-T88.9, Z00-Z99, classification that represents a health condition due to an external cause. Though they are most applicable to injuries, they are also valid for use with such things as infections or diseases due to an external source, and other health conditions, such as a heart attack that occurs during strenuous physical activity.

Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026

References

• CMS — ICD-10-CM Official Code Set and Guidelines, FY2026
• CDC/NCHS — ICD-10-CM Files and Browser Tool