| Full description | Adverse effect of fentanyl or fentanyl analogs, subsequent encounter |
| Billable | Yes |
| Chapter | Chapter 19: Injury, poisoning and certain other consequences of external causes (S00-T88) |
| Section | Poisoning by, adverse effects of and underdosing of drugs, medicaments and biological substances (T36-T50) |
| Parent code | T40.415 — Adverse effect of fentanyl or fentanyl analogs |