T25.439S Corrosion of unspecified degree of unspecified toe(s) (nail), sequela

Billable ICD-10-CM code, FY2026.

Built from T25.439 with 7th character S (sequela).

Applies from T25 Burn and corrosion of ankle and foot

7th character note

• The appropriate 7th character is to be added to each code from category T25

7th character required

• A — initial encounter
• D — subsequent encounter
• S — sequela

Applies from T25.4 Corrosion of unspecified degree of ankle and foot

Code first

• (T51-T65) to identify chemical and intent

Use additional code

• external cause code to identify place (Y92)

Code annotations containing back-references to T25.439S

Back-references to T25.43

• Type 2 Excludes: T25.42 Corrosion of unspecified degree of foot ("corrosion of unspecified degree of toe(s) (nail) (T25.43-)")

Back-references to T25

• Type 2 Excludes: T24 Burn and corrosion of lower limb, except ankle and foot ("burn and corrosion of ankle and foot (T25.-)")
• Type 1 Excludes: T66 Radiation sickness, unspecified ("burns (T20-T31)")
• Type 2 Excludes: T67 Effects of heat and light ("burns (T20-T31)")
• Type 2 Excludes: T75 Other and unspecified effects of other external causes ("burns (electric) (T20-T31)")

Diagnosis Index entries for T25.439S

• Corrosion (injury) (acid) (caustic) (chemical) (lime) (external) (internal) › toe

Nearby codes

• T25.432D Corrosion of unspecified degree of left toe(s) (nail), subsequent encounter
• T25.432S Corrosion of unspecified degree of left toe(s) (nail), sequela
• T25.439 Corrosion of unspecified degree of unspecified toe(s) (nail)
• T25.439A Corrosion of unspecified degree of unspecified toe(s) (nail), initial encounter
• T25.439D Corrosion of unspecified degree of unspecified toe(s) (nail), subsequent encounter
• T25.439S Corrosion of unspecified degree of unspecified toe(s) (nail), sequela (this code)
• T25.49 Corrosion of unspecified degree of multiple sites of ankle and foot
• T25.491 Corrosion of unspecified degree of multiple sites of right ankle and foot
• T25.491A Corrosion of unspecified degree of multiple sites of right ankle and foot, initial encounter
• T25.491D Corrosion of unspecified degree of multiple sites of right ankle and foot, subsequent encounter
• T25.491S Corrosion of unspecified degree of multiple sites of right ankle and foot, sequela