ICD-10-CM Tabular Index · Chapter 20 · FY 2026 X30

Exposure to excessive natural heat (X30) ICD-10-CM

The X30 code range covers exposure to excessive natural heat with 4 ICD-10-CM diagnosis codes. 3 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.

✓ Built from the official CMS FY 2026 datasetEffective Oct 1, 2025 – Sep 30, 2026
4
Diagnosis Codes
3
Billable Codes
X30
Code Range
X30–X39
Parent Section

Inclusion Terms

These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.

Type 1 Excludes

A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.

7th Character Note

Certain ICD-10-CM categories have applicable 7th characters. The applicable 7th character is required for all codes within the category, or as the notes in the Tabular List instruct. The 7th character must always be the 7th character in the data field. If a code that requires a 7th character is not 6 characters, a placeholder X must be used to fill in the empty characters.

7th Character

Indicates that a seventh character is to be assigned to codes in a subcategory.

ICD-10-CM

Codes in the X30 Range 4 codes · 3 billable

4 of 4 shown
  • X30 Exposure to excessive natural heatNon-billable
  • X30.XXXA Exposure to excessive natural heat, initial encounter
  • X30.XXXD Exposure to excessive natural heat, subsequent encounter
  • X30.XXXS Exposure to excessive natural heat, sequela

About the X30 Code Range

The ICD-10 code X30 and its variants are used specifically to document cases of exposure to excessive natural heat. These codes help identify and classify health issues related to heat-related conditions caused by environmental heat stress.

The code X30 covers general exposure to excessive natural heat, while the extensions X30.XXXA, X30.XXXD, and X30.XXXS specify the stage of care: initial encounter, subsequent encounter, and sequela, respectively. Conditions often referred to using terms like heatwave, accident due to hot weather, heat-induced dermatosis, or simply exposure to heat fall under these codes. Using the ICD-10 code for exposure to excessive natural heat assists healthcare professionals in accurately recording heat-related illnesses or injuries caused by prolonged heat exposure, guiding treatment decisions and tracking public health trends related to heat emergencies.

Questions About This Page

How many billable codes are in the X30 range?

Of the 4 codes in this range, 3 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.

What does the X30 range classify?

The range classifies exposure to excessive natural heat. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.

Related References

Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.