T20.77XA vs T28.0
T20.77XA (Corrosion of third degree of neck, initial encounter) compared with T28.0 (Burn of mouth and pharynx), from the official CMS tabular data. Both may be reported when both conditions are documented (Excludes2).
Can these codes be reported together?
Yes, when both are documented. T20.77XA carries an Excludes2 note covering T28.0: “burn and corrosion of mouth and pharynx (T28.0)”
Excludes2 marks distinct conditions — both may be reported when both are documented.
Side by side
| T20.77XACorrosion of third degree of neck, initial encounter | T28.0Burn of mouth and pharynx | |
|---|---|---|
| Billing status | Billable | Non-billable header |
| Classification | S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88) | S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88) |
| Definition | Corrosion of third degree of neck, initial encounter is a billable ICD-10-CM diagnosis code (T20.77A). | Burn of mouth and pharynx is a non-billable ICD-10-CM category code (T28.0). |
| 7th character | The appropriate 7th character is to be added to each code from category T20 | The appropriate 7th character is to be added to each code from category T28 |
| 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 | external cause code to identify place (Y92) code from category T31 or T32 to identify extent of body surface involved | external cause code to identify the source and intent of the burn (X00-X19, X75-X77, X96-X98) external cause code to identify place (Y92) |
| Code first | (T51-T65) to identify chemical and intent | — |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources