T38.3X4 vs T38.3X6

T38.3X4 (Poisoning by insulin and oral hypoglycemic [antidiabetic] drugs, undetermined) compared with T38.3X6 (Underdosing of insulin and oral hypoglycemic [antidiabetic] drugs), from the official CMS tabular data. T38.3X4 and T38.3X6 code the same substance (Acetohexamide) with a different intent.

Relationship

Informational

Drug table relationship

T38.3X4

Poisoning by insulin and oral hypoglycemic [antidiabetic] drugs, undetermined

↔

T38.3X6

Underdosing of insulin and oral hypoglycemic [antidiabetic] drugs

Same substance, different circumstance of exposure.

Same substance — underdosing (Acetohexamide)

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. T38.3X4 and T38.3X6 code the same substance (Acetohexamide) 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

	T38.3X4Poisoning by insulin and oral hypoglycemic [antidiabetic] drugs, undetermined	T38.3X6Underdosing of insulin and oral hypoglycemic [antidiabetic] drugs
Billing status	Non-billable header Report instead: T38.3X4A, T38.3X4D, T38.3X4S	Non-billable header Report instead: T38.3X6A, T38.3X6D, T38.3X6S
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 insulin and oral hypoglycemic [antidiabetic] drugs, undetermined is a non-billable ICD-10-CM category code (T38.3X4).	Underdosing of insulin and oral hypoglycemic [antidiabetic] drugs is a non-billable ICD-10-CM category code (T38.3X6).
7th character	The appropriate 7th character is to be added to each code from category T38	The appropriate 7th character is to be added to each code from category T38
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