Skip to main content
ICD-10/T42.71XA

T42.71XA ICD-10-CM Code: Poisoning by unspecified antiepileptic and sedative-hypnotic drugs, accidental (unintentional), initial encounter

Billing Status: YES. This is a valid, specific, and billable ICD-10-CM reference.

Inpatient Payment Groups (MS-DRG)

MS-DRGs this diagnosis helps define, as principal or secondary, per the CMS ICD-10-CM/PCS MS-DRG Definitions Manual v43.0 (FY2026), Appendix B.

  • MS-DRG 917 — POISONING AND TOXIC EFFECTS OF DRUGS WITH MCC (MDC 21)
  • MS-DRG 918 — POISONING AND TOXIC EFFECTS OF DRUGS WITHOUT MCC (MDC 21)

A diagnosis appearing in a group's logic does not by itself determine the DRG assigned to a stay; the grouper uses the full claim.

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

Official Registry Overview & Definition

Poisoning by unspecified antiepileptic and sedative-hypnotic drugs, accidental (unintentional), initial encounter is a billable ICD-10-CM diagnosis code (T42.71A).

Official Tabular Instructional Notes

Sequencing, inclusion, and exclusion notes published for T42.71XA in the official ICD-10-CM tabular list.

Includes

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

  • 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

Inclusion Terms

Alternative terms the tabular list files under this code.

  • Poisoning by antiepileptic and sedative-hypnotic drugs NOS

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.

  • drug dependence and related mental and behavioral disorders due to psychoactive substance use (F10.--F19.-)
  • 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

Does T42.71XA require a 7th character?

Yes. The appropriate 7th character is to be added to each code from category T42.

Nearest Codes in This Family

Official ICD-10-CM classifications closest to T42.71XA in its code family, with their registry titles.

  • T42.6X6A — Underdosing of other antiepileptic and sedative-hypnotic drugs, initial encounter
  • T42.6X6D — Underdosing of other antiepileptic and sedative-hypnotic drugs, subsequent encounter
  • T42.6X6S — Underdosing of other antiepileptic and sedative-hypnotic drugs, sequela
  • T42.7 — Poisoning by, adverse effect of and underdosing of unspecified antiepileptic and sedative-hypnotic drugs
  • T42.71 — Poisoning by unspecified antiepileptic and sedative-hypnotic drugs, accidental (unintentional)
  • T42.71XD — Poisoning by unspecified antiepileptic and sedative-hypnotic drugs, accidental (unintentional), subsequent encounter
  • T42.71XS — Poisoning by unspecified antiepileptic and sedative-hypnotic drugs, accidental (unintentional), sequela
  • T42.72 — Poisoning by unspecified antiepileptic and sedative-hypnotic drugs, intentional self-harm
  • T42.72XA — Poisoning by unspecified antiepileptic and sedative-hypnotic drugs, intentional self-harm, initial encounter
  • T42.72XD — Poisoning by unspecified antiepileptic and sedative-hypnotic drugs, intentional self-harm, subsequent encounter

View all codes in the T42 family