T20.411A (Corrosion of unspecified degree of right ear [any part, except ear drum], initial encounter) compared with T20.411S (Corrosion of unspecified degree of right ear [any part, except ear drum], sequela), from the official CMS tabular data. T20.411A and T20.411S code the same injury at a different phase of treatment. MedCoder-derived
Same underlying diagnosis, different encounter phase.
The 7th character records the phase of care for the encounter being coded, so a single encounter takes one of these characters, not several. Review whether both phases belong on the same episode of care.
Source: ICD-10-CM Official Guidelines, Section I.C.19.a
Same injury, other encounter phase. T20.411A and T20.411S code the same injury at a different phase of treatment, set by the 7th character.
The 7th character records the type of care given at the encounter being coded (ICD-10-CM Official Guidelines, Section I.C.19.a), so one encounter takes one of these, not both.
| T20.411ACorrosion of unspecified degree of right ear [any part, except ear drum], initial encounter | T20.411SCorrosion of unspecified degree of right ear [any part, except ear drum], sequela | |
|---|---|---|
| Billing status | Billable | Billable |
| 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 unspecified degree of right ear [any part, except ear drum], initial encounter is a billable ICD-10-CM diagnosis code (T20.411A). | Corrosion of unspecified degree of right ear [any part, except ear drum], sequela is a billable ICD-10-CM diagnosis code (T20.411S). |
| 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 T20 |
| 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] | 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 place (Y92) code from category T31 or T32 to identify extent of body surface involved |
| Code first | (T51-T65) to identify chemical and intent | (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