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ICD-10/T49.91

T49.91 ICD-10-CM Code: Poisoning by unspecified topical agent, accidental (unintentional)

Billing Status: NO. This is a clinician non-billable / parent hierarchy grouping in the ICD-10-CM system.

Code Set: Valid FY2026 and FY2027. FY2026 took effect October 1, 2025.

Official Registry Overview & Definition

Poisoning by unspecified topical agent, accidental (unintentional) is a non-billable ICD-10-CM category code (T49.91). A more specific billable subcode must be selected for claims submission.

Official Tabular Instructional Notes

Sequencing, inclusion, and exclusion notes published for T49.91 in the official ICD-10-CM tabular list.

Includes

Conditions the official ICD-10-CM tabular list includes under this code.

  • 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
  • underdosing by (inadvertently) (deliberately) taking less substance than prescribed or instructed

Excludes1 — Not Coded Here

Conditions that can never be reported with this code; the two are mutually exclusive.

  • toxic reaction to local anesthesia in pregnancy (O29.3-)

Excludes2 — Not Included Here

Conditions not covered by this code, but which may be reported alongside it when both are present.

  • abuse and dependence of psychoactive substances (F10-F19)
  • abuse of non-dependence-producing substances (F55.-)
  • immunodeficiency due to drugs (D84.821)
  • drug reaction and poisoning affecting newborn (P00-P96)
  • pathological drug intoxication (inebriation) (F10-F19)

Code First

Underlying conditions that must be sequenced before this code.

  • Code first, for adverse effects, the nature of the adverse effect, such as:
  • adverse effect NOS (T88.7)
  • aspirin gastritis (K29.-)
  • blood disorders (D56-D76)
  • contact dermatitis (L23-L25)
  • dermatitis due to substances taken internally (L27.-)
  • nephropathy (N14.0-N14.2)

Use Additional Code

Supplementary codes the tabular list directs you to add.

  • Use additional code(s) to specify:
  • manifestations of poisoning
  • underdosing or failure in dosage during medical and surgical care (Y63.6, Y63.8-Y63.9)
  • underdosing of medication regimen (Z91.12-, Z91.13-)

Frequently Asked Questions (FAQ) & Clinical Guidance

Can T49.91 be billed directly?

No. T49.91 (Poisoning by unspecified topical agent, accidental (unintentional)) is a non-billable ICD-10-CM category code. A more specific billable subcode must be selected based on clinical documentation.

Does T49.91 require a 7th character?

Yes. The appropriate 7th character is to be added to each code from category T49.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to T49.91 in its code family, with their registry titles.

  • T49.8X6 — Underdosing of other topical agents
  • T49.8X6A — Underdosing of other topical agents, initial encounter
  • T49.8X6D — Underdosing of other topical agents, subsequent encounter
  • T49.8X6S — Underdosing of other topical agents, sequela
  • T49.9 — Poisoning by, adverse effect of and underdosing of unspecified topical agent
  • T49.91XA — Poisoning by unspecified topical agent, accidental (unintentional), initial encounter
  • T49.91XD — Poisoning by unspecified topical agent, accidental (unintentional), subsequent encounter
  • T49.91XS — Poisoning by unspecified topical agent, accidental (unintentional), sequela
  • T49.92 — Poisoning by unspecified topical agent, intentional self-harm
  • T49.92XA — Poisoning by unspecified topical agent, intentional self-harm, initial encounter

View all codes in the T49 family

Associated Substances (5)

Substances from the official ICD-10-CM Table of Drugs and Chemicals that map to this code.

  • External medications (skin) (mucous membrane)
  • Liniments NEC
  • Lotions NEC
  • Mucous membrane agents (external)
  • Topical action drug NEC