X31 – Exposure to excessive natural cold
ICD-10-CM 2027 diagnosis code · Exposure to forces of nature
ICD-10-CM code
X31
- Code
X31(claims format:X31)- Description
- Exposure to excessive natural cold
- Billable
- No – use a more specific code below
- Valid for
- Dates of service October 1, 2026 – September 30, 2027 (FY2027)
- Chapter
- 20. External causes of morbidity (V00-Y99)
- Block
- X30-X39 Exposure to forces of nature
Billable codes under X31
X31 is a header code and cannot be used on claims. Choose the most specific code:
7th character values
Codes in this category need a 7th character to describe the encounter or episode of care (use placeholder X for empty positions).
| Character | Meaning |
|---|---|
A | initial encounter |
D | subsequent encounter |
S | sequela |
Notes for X31
Applicable to:
- Excessive cold as the cause of chilblains NOS
- Excessive cold as the cause of immersion foot or hand
- Exposure to cold NOS
- Exposure to weather conditions
Excludes1 (not coded here):
7th character note:
- The appropriate 7th character is to be added to code X31
Frequently asked questions
What is ICD-10 code X31?
X31 is the ICD-10-CM code for exposure to excessive natural cold, in the block X30-X39 (Exposure to forces of nature).
Is X31 a billable code?
No. X31 is a header code with more specific child codes; report one of the billable codes listed above.
Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.