| Billable | No — use a more specific child code |
| Chapter | Chapter 19: Injury, poisoning and certain other consequences of external causes (S00-T88) |
| Section | Burns and corrosions of external body surface, specified by site (T20-T25) |
| Parent code | T23.21 — Burn of second degree of thumb (nail) |
| Requires 7th character | Yes |