T49.4X5 vs T49.4X6

T49.4X5 (Adverse effect of keratolytics, keratoplastics, and other hair treatment drugs and preparations) compared with T49.4X6 (Underdosing of keratolytics, keratoplastics, and other hair treatment drugs and preparations), from the official CMS tabular data. T49.4X5 and T49.4X6 code the same substance (Allantoin) with a different intent.

Relationship

Informational

Drug table relationship

T49.4X5

Adverse effect of keratolytics, keratoplastics, and other hair treatment drugs and preparations

↔

T49.4X6

Underdosing of keratolytics, keratoplastics, and other hair treatment drugs and preparations

Same substance, different circumstance of exposure.

Same substance — underdosing (Allantoin)

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. T49.4X5 and T49.4X6 code the same substance (Allantoin) 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

	T49.4X5Adverse effect of keratolytics, keratoplastics, and other hair treatment drugs and preparations	T49.4X6Underdosing of keratolytics, keratoplastics, and other hair treatment drugs and preparations
Billing status	Non-billable header	Non-billable header
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	Adverse effect of keratolytics, keratoplastics, and other hair treatment drugs and preparations is a non-billable ICD-10-CM category code (T49.4X5).	Underdosing of keratolytics, keratoplastics, and other hair treatment drugs and preparations is a non-billable ICD-10-CM category code (T49.4X6).
7th character	The appropriate 7th character is to be added to each code from category T49	The appropriate 7th character is to be added to each code from category T49
Includes	poisoning by, adverse effect of and underdosing of glucocorticoids, topically used adverse effect of correct substance properly administered poisoning by overdose of substance poisoning by wrong substance given or taken in error	poisoning by, adverse effect of and underdosing of glucocorticoids, topically used adverse effect of correct substance properly administered poisoning by overdose of substance poisoning by wrong substance given or taken in error
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