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T42.74XA ICD-10-CM Code: Poisoning by unspecified antiepileptic and sedative-hypnotic drugs, undetermined, 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, 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.

Official Registry Overview & Definition

Poisoning by unspecified antiepileptic and sedative-hypnotic drugs, undetermined, initial encounter is a billable ICD-10-CM diagnosis code (T42.74A).

Official Tabular Instructional Notes

Sequencing, inclusion, and exclusion notes published for T42.74XA 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

Excludes1 — Not Coded Here

Conditions generally not reported together with this code (Excludes1) -- an error unless the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Excludes2 — Not Included Here

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

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 Compared Codes

The official Excludes notes on T42.74XA name these codes. Each comparison page covers when the two can — or must not — be reported together.

Change history

No changes recorded for this code — unchanged since the FY2016 baseline of the change ledger.

Verify Before Coding

  • No Medicare Code Editor or MS-DRG Definitions Manual restrictions apply to this code.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim.

Contextual Map

Every relationship of T42.74XA in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Hierarchy

  • S00-T88 — Chapter 19: Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88) (S00-T88) [Hierarchy]
  • T36-T50 — Poisoning by, adverse effects of and underdosing of drugs, medicaments and biological substances [Hierarchy]
  • T42-T43 — Anticonvulsants & Psychotropics [Hierarchy]

Referenced by Excludes2 notes

  • F13.2 — Sedative, hypnotic or anxiolytic-related dependence [Excludes2](via T42.-): “sedative, hypnotic, or anxiolytic poisoning (T42.-)” · check together

Clinical classification (CCSR)

  • INJ022 — Poisoning by drugs, initial encounter [CCSR]
  • EXT014 — External cause codes: poisoning by drug [CCSR]
  • EXT023 — External cause codes: intent of injury, undetermined [CCSR]
  • MBD020 — Sedative-related disorders [CCSR]

Potential MS-DRG

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

MDC crossing · procedures (32029)

  • MDC 21 — Injuries, Poisonings and Toxic Effects of Drugs [MDC crossing]: “Injuries, Poisonings and Toxic Effects of Drugs — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs.”
  • 0016070 — Bypass Cerebral Ventricle to Nasopharynx with Autologous Tissue Substitute, Open Approach [Same-MDC procedure]: “Bypass Cerebral Ventricle to Nasopharynx with Autologous Tissue Substitute, Open Approach — grouped in MDC 21, the procedure side of this code's crossing.” · check together
  • 0016071 — Bypass Cerebral Ventricle to Mastoid Sinus with Autologous Tissue Substitute, Open Approach [Same-MDC procedure]: “Bypass Cerebral Ventricle to Mastoid Sinus with Autologous Tissue Substitute, Open Approach — grouped in MDC 21, the procedure side of this code's crossing.” · check together
  • 0016072 — Bypass Cerebral Ventricle to Atrium with Autologous Tissue Substitute, Open Approach [Same-MDC procedure]: “Bypass Cerebral Ventricle to Atrium with Autologous Tissue Substitute, Open Approach — grouped in MDC 21, the procedure side of this code's crossing.” · check together
  • 0016073 — Bypass Cerebral Ventricle to Blood Vessel with Autologous Tissue Substitute, Open Approach [Same-MDC procedure]: “Bypass Cerebral Ventricle to Blood Vessel with Autologous Tissue Substitute, Open Approach — grouped in MDC 21, the procedure side of this code's crossing.” · check together
  • 0016074 — Bypass Cerebral Ventricle to Pleural Cavity with Autologous Tissue Substitute, Open Approach [Same-MDC procedure]: “Bypass Cerebral Ventricle to Pleural Cavity with Autologous Tissue Substitute, Open Approach — grouped in MDC 21, the procedure side of this code's crossing.” · check together
  • and 32024 more

Nearest codes (40)

  • T42 — Poisoning by, adverse effect of and underdosing of antiepileptic, sedative- hypnotic and antiparkinsonism drugs [Sibling]
  • T42.6X5D — Adverse effect of other antiepileptic and sedative-hypnotic drugs, subsequent encounter [Sibling]
  • T42.6X5S — Adverse effect of other antiepileptic and sedative-hypnotic drugs, sequela [Sibling]
  • T42.6X6 — Underdosing of other antiepileptic and sedative-hypnotic drugs [Sibling]
  • T42.6X6A — Underdosing of other antiepileptic and sedative-hypnotic drugs, initial encounter [Sibling]
  • T42.6X6D — Underdosing of other antiepileptic and sedative-hypnotic drugs, subsequent encounter [Sibling]
  • T42.6X6S — Underdosing of other antiepileptic and sedative-hypnotic drugs, sequela [Sibling]
  • T42.7 — Poisoning by, adverse effect of and underdosing of unspecified antiepileptic and sedative-hypnotic drugs [Sibling]
  • and 32 more

Referenced by Other Codes

Clinical classification (AHRQ CCSR):INJ022 — Poisoning by drugs, initial encounter (default); EXT014 — External cause codes: poisoning by drug; EXT023 — External cause codes: intent of injury, undetermined; MBD020 — Sedative-related disorders.

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Potential MS-DRG Relationships (FY2026)

Not on the CMS CC/MCC list — as a secondary diagnosis this code does not change MS-DRG severity.

Named in the grouper logic of 2 MS-DRGs: DRG 917 (MDC 21), DRG 918 (MDC 21).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Official ICD-10-CM tabular notes on other codes that name T42.74XA or its code family.

1 Excludes2 notes: F13.2 (via T42.-).

Frequently Asked Questions (FAQ) & Clinical Guidance

Does T42.74XA 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 T42.74XA in its code family, with their registry titles.

  • T42.73 — Poisoning by unspecified antiepileptic and sedative-hypnotic drugs, assault
  • T42.73XA — Poisoning by unspecified antiepileptic and sedative-hypnotic drugs, assault, initial encounter
  • T42.73XD — Poisoning by unspecified antiepileptic and sedative-hypnotic drugs, assault, subsequent encounter
  • T42.73XS — Poisoning by unspecified antiepileptic and sedative-hypnotic drugs, assault, sequela
  • T42.74 — Poisoning by unspecified antiepileptic and sedative-hypnotic drugs, undetermined
  • T42.74XD — Poisoning by unspecified antiepileptic and sedative-hypnotic drugs, undetermined, subsequent encounter
  • T42.74XS — Poisoning by unspecified antiepileptic and sedative-hypnotic drugs, undetermined, sequela
  • T42.75 — Adverse effect of unspecified antiepileptic and sedative-hypnotic drugs
  • T42.75XA — Adverse effect of unspecified antiepileptic and sedative-hypnotic drugs, initial encounter
  • T42.75XD — Adverse effect of unspecified antiepileptic and sedative-hypnotic drugs, subsequent encounter

View all codes in the T42 family