Coding and coverage · ICD-10-CM

T20

T20.7 Corrosion of third degree of head, face, and neck

Not billable (header)Chapter 19

This code needs a 7th character (use X as a placeholder for missing characters).

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Codes under this one

  • T20.70 Corrosion of third degree of head, face, and neck, unspecified siteHeader
  • T20.71 Corrosion of third degree of ear [any part, except ear drum]Header
  • T20.72 Corrosion of third degree of lip(s)Header
  • T20.73 Corrosion of third degree of chinHeader
  • T20.74 Corrosion of third degree of nose (septum)Header
  • T20.75 Corrosion of third degree of scalp [any part]Header
  • T20.76 Corrosion of third degree of forehead and cheekHeader
  • T20.77 Corrosion of third degree of neckHeader
  • T20.79 Corrosion of third degree of multiple sites of head, face, and neckHeader

Instructional notes

Chapter 19

Excludes2Not included here: the patient may have both; report both when both are present.
Use additional codeAdd a second code for the full picture.
  • code to identify any retained foreign body, if applicable (Z18.-)
Notes
  • Use secondary code(s) from Chapter 20, External causes of morbidity, to indicate cause of injury. Codes within the T section that include the external cause do not require an additional external cause code
  • The chapter uses the S-section for coding different types of injuries related to single body regions and the T-section to cover injuries to unspecified body regions as well as poisoning and certain other consequences of external causes.

T20

Excludes2Not included here: the patient may have both; report both when both are present.
  • 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 charactersThe appropriate 7th character is to be added to each code from category T20
  • A initial encounter
  • D subsequent encounter
  • S sequela

This code

Code firstSequence the underlying condition first.
  • (T51-T65) to identify chemical and intent
Use additional codeAdd a second code for the full picture.
  • external cause code to identify place (Y92)

Chapter 19: Injury, poisoning and certain other consequences of external causes · T07-T88 Injury, poisoning and certain other consequences of external causes (T07-T88)

Source: ICD-10-CM FY 2027 code descriptions and tabular list (CMS and CDC National Center for Health Statistics), effective 2026-10-01 through 2027-09-30 · CMS ICD-10 files. HCC mapping: CMS-HCC V28, payment year 2027. As of 2026-11-04.

Coverage and payment depend on the claim details; confirm with the Medicare Administrative Contractor.