T20.42 ICD-10-CM Code: Corrosion of unspecified degree of lip(s)
Billing Status: NO. This is a clinician non-billable / parent hierarchy grouping in the ICD-10-CM system.
Official Registry Overview & Definition
Official Tabular Instructional Notes
Sequencing, inclusion, and exclusion notes published for T20.42 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.
- burn and corrosion of ear drum (T28.41, T28.91) Compare T20.42 vs T28.41 →
- burn and corrosion of eye and adnexa (T26.-) Compare T20.42 vs T26 →
- burn and corrosion of mouth and pharynx (T28.0) Compare T20.42 vs T28.0 →
Code First
Underlying conditions that must be sequenced before this code.
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), lip (s)
Frequently Compared Codes
The official Excludes notes on T20.42 name these codes. Each comparison page covers when the two can — or must not — be reported together.
Change history
No changes recorded for this code — unchanged since the FY2016 baseline of the change ledger.
Verify Before Coding
- Not billable as written — a more specific code is required: T20.42XA, T20.42XD, T20.42XS.
- Requires a 7th character. "The appropriate 7th character is to be added to each code from category T20" Options: T20.42XA, T20.42XD, T20.42XS
From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim.
Relationships & Classification
Official ICD-10-CM tabular notes on other codes that name T20.42 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.
Contextual Map
Every relationship of T20.42 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), lip (s)[Index term]
Nearest codes (40)
- T20 — Burn and corrosion of head, face, and neck [Sibling]
- T20.39XD — Burn of third degree of multiple sites of head, face, and neck, subsequent encounter [Sibling]
- T20.39XS — Burn of third degree of multiple sites of head, face, and neck, sequela [Sibling]
- T20.4 — Corrosion of unspecified degree of head, face, and neck [Sibling]
- T20.40 — Corrosion of unspecified degree of head, face, and neck, unspecified site [Sibling]
- T20.40XA — Corrosion of unspecified degree of head, face, and neck, unspecified site, initial encounter [Sibling]
- T20.40XD — Corrosion of unspecified degree of head, face, and neck, unspecified site, subsequent encounter [Sibling]
- T20.40XS — Corrosion of unspecified degree of head, face, and neck, unspecified site, sequela [Sibling]
- and 32 more
Frequently Asked Questions (FAQ) & Clinical Guidance
Can T20.42 be billed directly?
No. T20.42 (Corrosion of unspecified degree of lip(s)) is a non-billable ICD-10-CM category code. A more specific billable subcode must be selected based on clinical documentation.
Does T20.42 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 T20.42 in its code family, with their registry titles.
- T20.412S — Corrosion of unspecified degree of left ear [any part, except ear drum], sequela
- T20.419 — Corrosion of unspecified degree of unspecified ear [any part, except ear drum]
- T20.419A — Corrosion of unspecified degree of unspecified ear [any part, except ear drum], initial encounter
- T20.419D — Corrosion of unspecified degree of unspecified ear [any part, except ear drum], subsequent encounter
- T20.419S — Corrosion of unspecified degree of unspecified ear [any part, except ear drum], sequela
- T20.42XA — Corrosion of unspecified degree of lip(s), initial encounter
- T20.42XD — Corrosion of unspecified degree of lip(s), subsequent encounter
- T20.42XS — Corrosion of unspecified degree of lip(s), sequela
- T20.43 — Corrosion of unspecified degree of chin
- T20.43XA — Corrosion of unspecified degree of chin, initial encounter