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T42.4X4 vs T42.4X6

T42.4X4 (Poisoning by benzodiazepines, undetermined) compared with T42.4X6 (Underdosing of benzodiazepines), from the official CMS tabular data. T42.4X4 and T42.4X6 code the same substance (Alprazolam) with a different intent.

Can these codes be reported together?

Same substance, different intent. T42.4X4 and T42.4X6 code the same substance (Alprazolam) with a different circumstance of exposure.

From the CMS Table of Drugs and Chemicals: accidental poisoning, intentional self-harm, assault, undetermined intent, adverse effect and underdosing are mutually exclusive columns — only one of them applies to a given encounter.

Side by side

T42.4X4Poisoning by benzodiazepines, undeterminedT42.4X6Underdosing of benzodiazepines
Billing statusNon-billable headerNon-billable header
ClassificationS00-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)
DefinitionPoisoning by benzodiazepines, undetermined is a non-billable ICD-10-CM category code (T42.4X4).Underdosing of benzodiazepines is a non-billable ICD-10-CM category code (T42.4X6).
7th characterThe appropriate 7th character is to be added to each code from category T42The appropriate 7th character is to be added to each code from category T42
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