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T24.632A vs T24.639A

T24.632A (Corrosion of second degree of left lower leg, initial encounter) compared with T24.639A (Corrosion of second degree of unspecified lower leg, initial encounter), from the official CMS tabular data. T24.632A and T24.639A code the same condition on opposite sides. MedCoder-derived

Relationship

Review

Laterality relationship

T24.632A
Left
Corrosion of second degree of left lower leg, initial encounter
T24.639A
Unspecified
Corrosion of second degree of unspecified lower leg, initial encounter

Same condition; these differ only in which side is documented.

These codes share a category and title and differ only in the side affected. The documentation decides which applies, and a bilateral code is reported only where the code set provides one.

Source: ICD-10-CM tabular list (laterality variant derived from the code title)

Can these codes be reported together?

Same condition, opposite side. T24.632A and T24.639A name the same condition on opposite sides of the body.

Same category and title, differing only in which side is affected — the documentation decides which one applies, and a bilateral code is reported only where the code set provides one.

Side by side

T24.632ACorrosion of second degree of left lower leg, initial encounterT24.639ACorrosion of second degree of unspecified lower leg, initial encounter
Billing statusBillableBillable
ClassificationS00-T88 — Injury, poisoning and certain other consequences of external causesS00-T88 — Injury, poisoning and certain other consequences of external causes
DefinitionCorrosion of second degree of left lower leg, initial encounter is a billable ICD-10-CM diagnosis code (T24.632A).Corrosion of second degree of unspecified lower leg, initial encounter is a billable ICD-10-CM diagnosis code (T24.639A).
7th characterThe appropriate 7th character is to be added to each code from category T24The appropriate 7th character is to be added to each code from category T24
Includes
burns and corrosions of first degree [erythema]
burns and corrosions of second degree [blisters][epidermal loss]
burns and corrosions of third degree [deep necrosis of underlying tissue] [full- thickness skin loss]
burns and corrosions of first degree [erythema]
burns and corrosions of second degree [blisters][epidermal loss]
burns and corrosions of third degree [deep necrosis of underlying tissue] [full- thickness skin loss]
Use additional code
external cause code to identify place (Y92)
code from category T31 or T32 to identify extent of body surface involved
external cause code to identify place (Y92)
code from category T31 or T32 to identify extent of body surface involved
Code first
(T51-T65) to identify chemical and intent
(T51-T65) to identify chemical and intent

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