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Compare/W93 vs X31

W93 vs X31

W93 (Exposure to excessive cold of man-made origin) compared with X31 (Exposure to excessive natural cold), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.

Can these codes be reported together?

No — do not report together. W93 carries an Excludes1 note covering X31: “natural cold (X31)”

Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

No — do not report together. X31 carries an Excludes1 note covering W93: “cold of man-made origin (W93.-)”

Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

No — do not report together. X31 carries an Excludes1 note covering W93: “contact with or inhalation of dry ice (W93.-)”

Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

No — do not report together. X31 carries an Excludes1 note covering W93: “contact with or inhalation of liquefied gas (W93.-)”

Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Side by side

W93Exposure to excessive cold of man-made originX31Exposure to excessive natural cold
Billing statusNon-billable header

Report instead: W93.01XA, W93.01XD, W93.01XS, W93.02XA, W93.02XD

Non-billable header

Report instead: X31.XXXA, X31.XXXD, X31.XXXS

ClassificationV00-Y99 — External Causes of Morbidity (V00-Y99)V00-Y99 — External Causes of Morbidity (V00-Y99)
DefinitionExposure to excessive cold of man-made origin is a non-billable ICD-10-CM category code (W93).Exposure to excessive natural cold is a non-billable ICD-10-CM category code (X31).
7th characterThe appropriate 7th character is to be added to each code from category W93The appropriate 7th character is to be added to code X31
Includes
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

Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources