T20.412 – Corrosion of unspecified degree of left ear [any part, except ear drum]

ICD-10-CM 2027 diagnosis code · Burns and corrosions of external body surface, specified by site

Non-billable header

ICD-10-CM code T20.412

Code: T20.412 (claims format: T20412)
Description: Corrosion of unspecified degree of left ear [any part, except ear drum]
Short description: Corrosion of unspecified degree of left ear
Billable: No – use a more specific code below
Valid for: Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter: 19. Injury, poisoning and certain other consequences of external causes (S00-T88)
Block: T20-T25 Burns and corrosions of external body surface, specified by site
Parent codes: T20 › T20.4 › T20.41

Billable codes under T20.412

T20.412 is a header code and cannot be used on claims. Choose the most specific code:

7th character values

Codes in this category need a 7th character to describe the encounter or episode of care.

Character	Meaning
`A`	initial encounter
`D`	subsequent encounter
`S`	sequela

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

T20 – Burn and corrosion of head, face, and neck

Excludes2 (not included here):

burn and corrosion of ear drum (T28.41, T28.91)
burn and corrosion of eye and adnexa (T26.-)
burn and corrosion of mouth and pharynx (T28.0)

7th character note:

The appropriate 7th character is to be added to each code from category T20

T20.4 – Corrosion of unspecified degree of head, face, and neck

Code first:

(T51-T65) to identify chemical and intent

Use additional code:

external cause code to identify place (Y92)

T20.41 – Corrosion of unspecified degree of ear [any part, except ear drum]

Excludes2 (not included here):

corrosion of ear drum (T28.91-)

Block T20-T25

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]

Use additional code:

code from category T31 or T32 to identify extent of body surface involved

Related codes in T20.41

Frequently asked questions

What is ICD-10 code T20.412?

T20.412 is the ICD-10-CM code for corrosion of unspecified degree of left ear [any part, except ear drum], in the block T20-T25 (Burns and corrosions of external body surface, specified by site).

Is T20.412 a billable code?

No. T20.412 is a header code with more specific child codes; report one of the billable codes listed above.

What category does T20.412 belong to?

It belongs to category T20 – Burn and corrosion of head, face, and neck.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.