T25.799A Corrosion of third degree of multiple sites of unspecified ankle and foot, initial encounter

Billable ICD-10-CM code, FY2026.

Built from T25.799 with 7th character A (initial encounter).

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 T25.7 Corrosion of third degree of ankle and foot

Code first

• (T51-T65) to identify chemical and intent

Use additional code

• external cause code to identify place (Y92)

Medicare Code Edits (MCE v43.1 (April 2026))

• Unspecified code (laterality): Unspecified codes for which a more specific code identifying laterality (right, left, bilateral) exists within the same code family.

Code annotations containing back-references to T25.799A

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 T25.799A

• Corrosion (injury) (acid) (caustic) (chemical) (lime) (external) (internal) › lower › limb › multiple sites, except ankle and foot › ankle and foot › third degree

Nearby codes

• T25.792 Corrosion of third degree of multiple sites of left ankle and foot
• T25.792A Corrosion of third degree of multiple sites of left ankle and foot, initial encounter
• T25.792D Corrosion of third degree of multiple sites of left ankle and foot, subsequent encounter
• T25.792S Corrosion of third degree of multiple sites of left ankle and foot, sequela
• T25.799 Corrosion of third degree of multiple sites of unspecified ankle and foot
• T25.799A Corrosion of third degree of multiple sites of unspecified ankle and foot, initial encounter (this code)
• T25.799D Corrosion of third degree of multiple sites of unspecified ankle and foot, subsequent encounter
• T25.799S Corrosion of third degree of multiple sites of unspecified ankle and foot, sequela