T23.421A Corrosion of unspecified degree of single right finger (nail) except thumb, initial encounter

Billable ICD-10-CM code, FY2026.

Built from T23.421 with 7th character A (initial encounter).

Applies from T23 Burn and corrosion of wrist and hand

7th character note

• The appropriate 7th character is to be added to each code from category T23

7th character required

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

Applies from T23.4 Corrosion of unspecified degree of wrist and hand

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 T23.421A

Back-references to T23

• Type 2 Excludes: T22 Burn and corrosion of shoulder and upper limb, except wrist and hand ("burn and corrosion of wrist and hand (T23.-)")
• 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 T23.421A

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

Nearby codes

• T23.419A Corrosion of unspecified degree of unspecified thumb (nail), initial encounter
• T23.419D Corrosion of unspecified degree of unspecified thumb (nail), subsequent encounter
• T23.419S Corrosion of unspecified degree of unspecified thumb (nail), sequela
• T23.42 Corrosion of unspecified degree of single finger (nail) except thumb
• T23.421 Corrosion of unspecified degree of single right finger (nail) except thumb
• T23.421A Corrosion of unspecified degree of single right finger (nail) except thumb, initial encounter (this code)
• T23.421D Corrosion of unspecified degree of single right finger (nail) except thumb, subsequent encounter
• T23.421S Corrosion of unspecified degree of single right finger (nail) except thumb, sequela
• T23.422 Corrosion of unspecified degree of single left finger (nail) except thumb
• T23.422A Corrosion of unspecified degree of single left finger (nail) except thumb, initial encounter
• T23.422D Corrosion of unspecified degree of single left finger (nail) except thumb, subsequent encounter