X31
ICD-10Non-billable categoryExposure to excessive natural cold
Official ICD-10-CM descriptor (FY2026)
Exposure to excessive natural cold
X31 is a category heading, not a billable code. CMS does not accept it on a claim; report one of the more specific codes beneath it.
Inclusion terms
- 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. An Excludes1 code should never be reported at the same time as the code above it.
- cold of man-made origin (W93.-)
- contact with or inhalation of dry ice (W93.-)
- contact with or inhalation of liquefied gas (W93.-)
7th character
- The appropriate 7th character is to be added to code X31
Permitted 7th characters
| A | initial encounter |
| D | subsequent encounter |
| S | sequela |
Where this code sits
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ICD-10-CM FY2026. Centers for Medicare & Medicaid Services (CMS) / National Center for Health Statistics (NCHS), “2026 ICD-10-CM Code Descriptions in Tabular Order” (icd10cm_order_2026.txt). Download the original file from cms.gov. Public domain (US Government work). Descriptors, billable flags and instructional notes on this page are reproduced from that file without modification. Krasyn adds no clinical guidance.