ICD-10-CM 2027 diagnosis code
X39.01Exposure to radon
X39.01 is a header code, so it can't be reported by itself. Choose one of the 3 more specific codes beneath it and add the required 7th character.
Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data
About X39.01
X39.01 is the ICD-10-CM diagnosis code for exposure to radon. It belongs to category X39 (exposure to other forces of nature), block X30-X39 (exposure to forces of nature) and chapter 20 (external causes of morbidity). It is a header code, so it can't be reported by itself; one of its 3 subcodes must be used instead.
Within X39.0 (exposure to natural radiation), X39.01 is specifically for exposure to radon. Related codes cover other natural radiation (X39.08).
Codes in this range require a 7th character: A for initial encounter, D for subsequent encounter and S for sequela. Use placeholder "X" characters to fill any empty positions before the 7th character.
It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.
7th character
The appropriate 7th character is to be added to each code from category X39
Notes that apply from higher levels
Instructions written at a parent level also apply to X39.01.
Broader instructions also apply from Chapter 20: External causes of morbidity.
Alphabetic index entries
3 entriesTerms in the official ICD-10-CM index that lead to X39.01.
- Forces of nature › radiation (natural) › radon
- Forces of nature › radon
- Radiation (exposure to) › natural NEC › radon
Code history
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
- No changes since FY2016.
Common questions about X39.01
Is X39.01 billable?
- No. X39.01 is a header code. Report one of its more specific subcodes instead.