Skip to main content
ICD-10/T20.79

T20.79 ICD-10-CM Code: Corrosion of third degree of multiple sites of head, face, and neck

Billing Status: NO. This is a clinician non-billable / parent hierarchy grouping in the ICD-10-CM system.

Official Registry Overview & Definition

Corrosion of third degree of multiple sites of head, face, and neck is a non-billable ICD-10-CM category code (T20.79). A more specific billable subcode must be selected for claims submission.

Official Tabular Instructional Notes

Sequencing, inclusion, and exclusion notes published for T20.79 in the official ICD-10-CM tabular list.

Includes

Conditions the official ICD-10-CM tabular list includes under this code.

  • 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]

Excludes2 — Not Included Here

Conditions not covered by this code, but which may be reported alongside it when both are present.

Code First

Underlying conditions that must be sequenced before this code.

  • (T51-T65) to identify chemical and intent

Use Additional Code

Supplementary codes the tabular list directs you to add.

  • external cause code to identify place (Y92)
  • Use additional code from category T31 or T32 to identify extent of body surface involved

Change history

No changes recorded for this code — unchanged since the FY2016 baseline of the change ledger.

Verify Before Coding

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim.

Contextual Map

Every relationship of T20.79 in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Hierarchy

  • S00-T88 — Chapter 19: Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88) (S00-T88) [Hierarchy]

Referenced by Excludes1 notes

  • T07 — Unspecified multiple injuries [Excludes1](via T20.-): “burns and corrosions (T20-T32)” · check together
  • T66 — Radiation sickness, unspecified [Excludes1](via T20.-): “burns (T20-T31)” · check together

Referenced by Excludes2 notes (121)

  • S00 — Superficial injury of head [Excludes2](via T20.-): “burns and corrosions (T20-T32)” · check together
  • S00-S09 — Injuries to the head (S00-S09) [Excludes2](via T20.-): “burns and corrosions (T20-T32)” · check together
  • S01 — Open wound of head [Excludes2](via T20.-): “burns and corrosions (T20-T32)” · check together
  • S02 — Fracture of skull and facial bones [Excludes2](via T20.-): “burns and corrosions (T20-T32)” · check together
  • S03 — Dislocation and sprain of joints and ligaments of head [Excludes2](via T20.-): “burns and corrosions (T20-T32)” · check together
  • S04 — Injury of cranial nerve [Excludes2](via T20.-): “burns and corrosions (T20-T32)” · check together
  • S05 — Injury of eye and orbit [Excludes2](via T20.-): “burns and corrosions (T20-T32)” · check together
  • S06 — Intracranial injury [Excludes2](via T20.-): “burns and corrosions (T20-T32)” · check together
  • and 113 more

Index entries

  • Corrosion (injury) (acid) (caustic) (chemical) (lime) (external) (internal), head (and face) (and neck), multiple sites, third degree[Index term]

Nearest codes (40)

  • T20 — Burn and corrosion of head, face, and neck [Sibling]
  • T20.71 — Corrosion of third degree of ear [any part, except ear drum] [Sibling]
  • T20.711 — Corrosion of third degree of right ear [any part, except ear drum] [Sibling]
  • T20.711A — Corrosion of third degree of right ear [any part, except ear drum], initial encounter [Sibling]
  • T20.711D — Corrosion of third degree of right ear [any part, except ear drum], subsequent encounter [Sibling]
  • T20.711S — Corrosion of third degree of right ear [any part, except ear drum], sequela [Sibling]
  • T20.712 — Corrosion of third degree of left ear [any part, except ear drum] [Sibling]
  • T20.712A — Corrosion of third degree of left ear [any part, except ear drum], initial encounter [Sibling]
  • and 32 more

Referenced by Other Codes

Official ICD-10-CM tabular notes on other codes that name T20.79 or its code family.

2 Excludes1 notes: T07 (via T20.-), T66 (via T20.-).

121 Excludes2 notes: S00 (via T20.-), S00-S09 (via T20.-), S01 (via T20.-), S02 (via T20.-), S03 (via T20.-), S04 (via T20.-), S05 (via T20.-), S06 (via T20.-), S07 (via T20.-), S08 (via T20.-) and 111 more.

Frequently Asked Questions (FAQ) & Clinical Guidance

Can T20.79 be billed directly?

No. T20.79 (Corrosion of third degree of multiple sites of head, face, and neck) is a non-billable ICD-10-CM category code. A more specific billable subcode must be selected based on clinical documentation.

Does T20.79 require a 7th character?

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

Nearest Codes in This Family

Official ICD-10-CM classifications closest to T20.79 in its code family, with their registry titles.

  • T20.76 — Corrosion of third degree of forehead and cheek
  • T20.76XA — Corrosion of third degree of forehead and cheek, initial encounter
  • T20.76XD — Corrosion of third degree of forehead and cheek, subsequent encounter
  • T20.76XS — Corrosion of third degree of forehead and cheek, sequela
  • T20.77 — Corrosion of third degree of neck
  • T20.77XA — Corrosion of third degree of neck, initial encounter
  • T20.77XD — Corrosion of third degree of neck, subsequent encounter
  • T20.77XS — Corrosion of third degree of neck, sequela
  • T20.79XA — Corrosion of third degree of multiple sites of head, face, and neck, initial encounter
  • T20.79XD — Corrosion of third degree of multiple sites of head, face, and neck, subsequent encounter

View all codes in the T20 family

Indexed Clinical Terms (1)

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code.

  • Corrosion (injury) (acid) (caustic) (chemical) (lime) (external) (internal), head (and face) (and neck), multiple sites, third degree