T25.421S Corrosion of unspecified degree of right foot, sequela

Billable ICD-10-CM code, FY2026.

Built from T25.421 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)

Applies from T25.42 Corrosion of unspecified degree of foot

Excludes2 (not included here)

• corrosion of unspecified degree of toe(s) (nail) (T25.43-)

Code annotations containing back-references to T25.421S

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 T25.421S

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

Nearby codes

• T25.419S Corrosion of unspecified degree of unspecified ankle, sequela
• T25.42 Corrosion of unspecified degree of foot
• T25.421 Corrosion of unspecified degree of right foot
• T25.421A Corrosion of unspecified degree of right foot, initial encounter
• T25.421D Corrosion of unspecified degree of right foot, subsequent encounter
• T25.421S Corrosion of unspecified degree of right foot, sequela (this code)
• T25.422 Corrosion of unspecified degree of left foot
• T25.422A Corrosion of unspecified degree of left foot, initial encounter
• T25.422D Corrosion of unspecified degree of left foot, subsequent encounter
• T25.422S Corrosion of unspecified degree of left foot, sequela
• T25.429 Corrosion of unspecified degree of unspecified foot