T48.902 vs T48.906

T48.902 (Poisoning by unspecified agents primarily acting on the respiratory system, intentional self-harm) compared with T48.906 (Underdosing of unspecified agents primarily acting on the respiratory system), from the official CMS tabular data. T48.902 and T48.906 code the same substance (Respiratory) with a different intent.

Relationship

Informational

Drug table relationship

T48.902

Poisoning by unspecified agents primarily acting on the respiratory system, intentional self-harm

↔

T48.906

Underdosing of unspecified agents primarily acting on the respiratory system

Same substance, different circumstance of exposure.

Same substance — underdosing (Respiratory)

Accidental poisoning, intentional self-harm, assault, undetermined intent, adverse effect and underdosing are mutually exclusive columns — exactly one applies to a given encounter.

Source: CMS Table of Drugs and Chemicals

Can these codes be reported together?

Same substance, different intent. T48.902 and T48.906 code the same substance (Respiratory) 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

	T48.902Poisoning by unspecified agents primarily acting on the respiratory system, intentional self-harm	T48.906Underdosing of unspecified agents primarily acting on the respiratory system
Billing status	Non-billable header Report instead: T48.902A, T48.902D, T48.902S	Non-billable header Report instead: T48.906A, T48.906D, T48.906S
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 agents primarily acting on the respiratory system, intentional self-harm is a non-billable ICD-10-CM category code (T48.902).	Underdosing of unspecified agents primarily acting on the respiratory system is a non-billable ICD-10-CM category code (T48.906).
7th character	The appropriate 7th character is to be added to each code from category T48	The appropriate 7th character is to be added to each code from category T48
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)

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Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources