T40.601A vs T40.601D
T40.601A (Poisoning by unspecified narcotics, accidental (unintentional), initial encounter) compared with T40.601D (Poisoning by unspecified narcotics, accidental (unintentional), subsequent encounter), from the official CMS tabular data. T40.601A and T40.601D code the same injury at a different phase of treatment.
Can these codes be reported together?
Same injury, other encounter phase. T40.601A and T40.601D 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.
Side by side
| T40.601APoisoning by unspecified narcotics, accidental (unintentional), initial encounter | T40.601DPoisoning by unspecified narcotics, accidental (unintentional), subsequent encounter | |
|---|---|---|
| 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 | Poisoning by unspecified narcotics, accidental (unintentional), initial encounter is a billable ICD-10-CM diagnosis code (T40.601A). | Poisoning by unspecified narcotics, accidental (unintentional), subsequent encounter is a billable ICD-10-CM diagnosis code (T40.601D). |
| 7th character | The appropriate 7th character is to be added to each code from category T40 | The appropriate 7th character is to be added to each code from category T40 |
| Includes | adverse effect of correct substance properly administered poisoning by overdose of substance poisoning by wrong substance given or taken in error underdosing by (inadvertently) (deliberately) taking less substance than prescribed or instructed | adverse effect of correct substance properly administered poisoning by overdose of substance poisoning by wrong substance given or taken in error underdosing by (inadvertently) (deliberately) taking less substance than prescribed or instructed |
| Use additional code | code(s) to specify: manifestations of poisoning underdosing or failure in dosage during medical and surgical care (Y63.6, Y63.8-Y63.9) | code(s) to specify: manifestations of poisoning underdosing or failure in dosage during medical and surgical care (Y63.6, Y63.8-Y63.9) |
| Code first | , for adverse effects, the nature of the adverse effect, such as: adverse effect NOS (T88.7) | , for adverse effects, the nature of the adverse effect, such as: adverse effect NOS (T88.7) |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources